Compositions and methods for treating influenza infection

Abstract

Pharmaceutical compositions comprising a dual hapten conjugate for treating viral infections such as influenza; and methods for treating such infections are disclosed herein.

Description

70849-04 COMPOSITIONS AND METHODS FOR TREATING INFLUENZA INFECTION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The application claims the benefit of priority from U.S. Appl. No.63 / 685,528, filed August 21, 2024; U.S. Appl. No. 63 / 708,668, filed October 17, 2024; and U.S. Appl. No. 5 63 / 789,850, filed April 16, 2025, each of which is incorporated by reference as if fully set forth herein. TECHNICAL FIELD

[0002] The invention described herein pertains to formulations of pharmaceutically active ingredients and methods for using pharmaceutically active ingredients to treat influenza 10 infections. BACKGROUND

[0003] Influenza is one of the most life-threatening disseminated diseases, resulting in about 3 to 5 million yearly cases of severe illness and about 250,000 to 500,000 yearly deaths. In addition to causing high morbidity and mortality, influenza imposes a substantial 15 social economic burden arising from the productivity lost and medical prevention and treatment.

[0004] Because influenza virus constantly changes via antigen shift and drift, vaccines often become ineffective against mutating strains. Though vaccines against common influenza antigens have proven successful in limiting the severity and spread of the virus during years 20 when the most aggressive viral strains are correctly predicted, due to the rapid evolution of the virus they have been only 19-60% effective over the past decade, and annual formulations of the vaccine often fail to match the most virulent strains, resulting in many vaccinated patients still contracting an infection. Further complicating this issue is that generally the highest risk populations have the highest numbers of people who either are ineligible for the 25 vaccine or are unable to develop immune responses to the vaccine.

[0005] Chemotherapeutic applications presently available are also limited. Approved anti- influenza drugs are either M2 ion channel inhibitors or neuraminidase inhibitors.

[0006] M2 ion channel inhibitors include amantadine and rimantadine. The mechanism of action of these drugs results from blocking the acid-activated viral M2 ion channel, and as a 30 consequence, inhibit the release of viral ribonucleoprotein from virion to host cytosol. However, both H1N1 and H3N2 viruses currently circulating in human populations are - 1 -70849-04 resistant to these inhibitors. Thus, Centers for Disease Control and Prevention (CDC) has advised against their use, due to the potential for rapid emergence of drug resistance.

[0007] The commonly used neuraminidase inhibitors include oseltamivir and zanamivir and act as competitive inhibitors competing with sialic acid to bind to the active site of 5 neuraminidase. While these inhibitors are effective against both influenza A and influenza B viruses, they have two major limitations. First, only small benefits have been observed for neuraminidase inhibitors in terms of symptom severity alleviation and sickness duration reduction (0.6-0.7 day out of 7 days). Second, this class of antivirals also suffer from the drug-resistant problem. An increase in the number of oseltamivir-resistant strains has been 10 noted since 2007 to 2008 season. In light of the limitations of the current anti-influenza chemotherapies, there is an urgent need to develop new anti-influenza drugs with novel mechanisms of action.

[0008] While prophylactic treatments, such as vaccines, play an important role in managing influenza’s medical burden, both current vaccines and antiviral agents should be 15 supplemented with new antiviral therapies to address future pandemic influenza years. A potent and broad-spectrum anti-influenza therapy is needed. In view of the foregoing, it is an object of the present disclosure to provide such a therapy. This and other objects and advantages, as well as inventive features, will be apparent from the detailed description provided herein. 20 SUMMARY

[0009] Pharmaceutical compositions comprising (i) conjugates of the formula: , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1 and A2 are each, 25 independently, a hapten; and (ii) non-ionic surfactants are described herein. In some embodiments, the compounds are of Formula I:or a pharmaceutically acceptable salt or solvate thereof wherein T is a radical of a ligand for a target protein of an influenza virus or a virus-infected cell; 30 L1, L2, and L3are each, an independently selected linker; and - 2 -70849-04 A1 and A2 are each, a radical of an independently selected hapten. In an illustrative embodiment, each of L1, L2, and L3is independently selected, and each may comprise a single divalent atom, or a chain of atoms. In another illustrative embodiment, L2may be a bond attaching L1to A1. In another illustrative embodiment, each of L3may be a bond 5 attaching L1to A2.

[0010] Pharmaceutical compositions for use in treating an influenza infection are described herein, where the pharmaceutical composition comprises (i) a therapeutically effective amount of a conjugate of the formula:, 10 and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0011] In many aspects, the pharmaceutical compositions are not solids.

[0012] Unit doses and unit dosage forms in single or divided form are described herein, 15 where the unit doses and unit dosage forms comprise (i) a therapeutically effective amount of a conjugate of the formula: , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1 and A2 are each, 20 independently, a hapten; and (ii) a non-ionic surfactant.

[0013] Methods for treating an influenza infection in a host animal are described herein, where the methods comprise administering to the host animal a composition comprising (i) a therapeutically effective amount of a conjugate of the formula: , 25 and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0014] Uses of compositions in the manufacture of medicaments for treating an influenza infection are described herein, where the compositions comprise (i) a therapeutically effective - 3 -70849-04 amount of a conjugate of the formula:, and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, 5 independently, a hapten and (ii) a non-ionic surfactant.

[0015] In a first illustrative embodiment, T is a radical of a neuraminidase inhibitor.

[0016] In a second illustrative embodiment, T is a radical of a hemagglutinin inhibitor.

[0017] In another illustrative embodiment, the haptens recruit endogenous antibodies present in the host animal. 10

[0018] In another aspect, the compositions, unit doses, and unit dosage forms described herein comprise a conjugate of the formula:and diastereomers thereof, also referred to herein as “Compound 24.”

[0019] In further aspects, methods of treating influenza and uses of compositions for treating 15 influenza with pharmaceutical compositions comprising:are described herein.

[0020] In further aspects, compositions, unit doses, and unit dosage forms comprising Compound 24 are described herein. 20

[0021] In additional aspects, methods of treating influenza and uses of compositions for treating influenza with pharmaceutical compositions comprising Compound 24 are described herein. - 4 -70849-04 BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG.1 shows plots of effectiveness of Compound 24 and other compounds with various routes of administration.

[0023] FIG.2 shows plots of effectiveness of Compound 24 and other compounds with 5 various routes of administration.

[0024] FIG.3 from Method Example 5 shows a graph of days after infection vs. survival (%) and days after infection vs. body weight (%) for mice (n = 5 / group) infected with 10 LD50of influenza A H3N2 / Wisconsin / 15 / 2009, intraperitoneal administration of human IgG (IVIg (GAMUNEX®-C) at 24 hours post-infection (hpi), and administration of Compound 10 24 at 48 hpi.

[0025] FIG.4 is from the study in Method Example 2 is a plot of TCID50 / mL (Tissue Culture Infectious Dose) as a function of dose (mg / kg). FIG.4 shows the viral titer measured by hemagglutination 24 hours after treatment with Tamiflu® (oseltamivir phosphate), vehicle (phosphate-buffered saline; “PBS”), or increasing concentrations of Compound 24 (the four 15 measurements shown with a “mg / kg” value reported). Mice treated with Compound 24 have a 100-fold reduction in infectious virus, as compared to the vehicle, and a greater than 10- fold reduction in infectious virus as compared to the standard of care.

[0026] FIG.5 is a synthetic scheme for Compound 11, which is used in the synthesis of Compound 24. 20

[0027] FIG.6 is a synthetic scheme for Compound 24.

[0028] FIG.7 shows example compounds of the invention.

[0029] FIG.8 is a plot of fluorescence intensity as a function of zanamivir-rhodamine. It shows that zanamivir-rhodamine binds to neuraminidase with a binding affinity of 8.253 nM.

[0030] FIG.9 are plots of fluorescence intensity as a function of the log[concentration] 25 (nM) for Compound 24 and zanamivir. FIG.9 shows the competitive binding of Compound 24 (left panel) and zanamivir (right panel) to neuraminidase-expressing HEK cells. It shows retained affinity for neuraminidase after incorporation into the conjugate Compound 24.

[0031] FIG.10 shows the cytokine response to various treatments, including Compound 24, in human PBMC (Method Example 6). 30

[0032] FIG.11 shows a plot of normalized fluorescence (RFU) as a function of the log of the concentration of Compound 24. FIG.11 shows neuraminidase inhibition activity of Compound 24 against multiple influenza strains. - 5 -70849-04

[0033] FIG.12 shows a plot of normalized fluorescence (RFU) as a function of the log of the concentration of Compound 41. FIG.12 shows neuraminidase inhibition activity of Compound 41 against multiple influenza strains (Method Example 7).

[0034] FIG.13 from Method Example 5 and shows graphs of cytokine and chemokine 5 levels measured in the lungs of mice from treatment (Compound 24 or Tamiflu®) or control groups.

[0035] FIG.14 from Method Example 5 and graphs of cytokine and chemokine levels measured in the serum of mice from treatment (Compound 24 or Tamiflu®) or control groups. 10

[0036] FIG.14A shows the in vivo efficacy of Compound 24 against seasonal flu strains A / California / 07 / 2009(H1N1) pdm09, B / Brisbane / 60 / 2008, and A / H3N2 / Wisconsin / 15 / 2009 in mice infected with 10x LD50titers compared to oseltamivir phosphate and vehicle control (N=5 / cohort).

[0037] FIG.14B shows the viral titer measured by hemagglutination 24 hours after 15 treatment with vehicle (PBS), oseltamivir phosphate, or Compound 24 in vivo against seasonal flu strains A / California / 07 / 2009(H1N1) pdm09, A / H3N2 / Wisconsin / 15 / 2009, and B / Brisbane / 60 / 2008 in mice infected with 10x LD50 titers (N=5 / cohort). Compound 24 demonstrates a statistically significant improvement over both vehicle control and oseltamivir phosphate positive control. 20

[0038] FIG 15A shows the in vivo efficacy of Compound 24 against A / Hong Kong / 2369 / 2009 (H1N1pdm09), a Tamiflu® resistant influenza A, in mice infected with 10x LD50 titers compared to oseltamivir phosphate and vehicle control (N=5 / cohort).

[0039] FIG.15B shows the body weight % (B) following administration of Compound 24, oseltamivir phosphate, or vehicle treated mice infected with Influenza A / Hong 25 Kong / 2369 / 2009 (H1N1pdm09, oseltamivir phosphate (Tamiflu®) Resistant).

[0040] FIG.15C shows the viral titers present in the lungs of mice treated with Compound 24, oseltamivir phosphate, or vehicle 24 hours after drug administration and 48 hours after infection with 10xLD50 of Influenza A strain – A / Hong Kong / 2369 / 2009 (H1N1pdm09, oseltamivir phosphate (Tamiflu®) Resistant). 30

[0041] FIG.16 shows the prevention of influenza transmission in co-housed guinea pigs by Compound 24.

[0042] FIG.17A the change in efficacy of Compound 24 compared to oseltamivir phosphate after 5 cycles of in vivo mutation as measured by neuraminidase inhibition. - 6 -70849-04

[0043] FIG.17B shows the change in virulence of influenza virus A / PR8 / 34 (H1N1) after 5 cycles of in vivo mutation using Compound 24 compared to oseltamivir phosphate as measured by LD50 measured in vivo.

[0044] FIG.18A shows IVIS imaging of Group 1 (mock) and Group 2 (infected and 5 vehicle treated mice).

[0045] FIG.18B shows IVIS imaging of Group 3 (infected and oseltamivir phosphate treated mice) and Group 4 (infected and Compound 24 treated mice) from Method Example 12.

[0046] FIG.19A shows antibody-dependent cellular cytotoxicity (ADCC) induced killing 10 of virus-infected HEK293 cells by Compound 24.

[0047] FIG.19B shows antibody-dependent cellular phagocytosis (ADCP) induced killing of virus-infected HEK293 cells by Compound 24.

[0048] FIG.19C shows complement dependent cytotoxicity (CDC) induced killing of virus-infected HEK293 cells by Compound 24. 15

[0049] FIG.20 shows the neuraminidase inhibition activity of Compound 24 intranasally (“IN”) against seasonal and drug-resistant influenza A and B strains.

[0050] FIG.21 shows the in vivo efficacy of Compound 24 against A / Illinois / 37 / 2018 (H1N1, Baloxavir Resistant) - Survival over Time. DETAILED DESCRIPTION 20

[0051] Several illustrative embodiments of the present disclosure are described by the following enumerated embodiments:

[0052] Embodiment 1 relates to a pharmaceutical composition comprising (i) a conjugate of the formula: , 25 and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0053] Embodiment 2 relates to a pharmaceutical composition for use in treating an influenza infection, the composition comprising (i) a therapeutically effective amount of a 30 conjugate of the formula: - 7 -70849-04, and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant. 5

[0054] Embodiment 3 relates to a unit dose or unit dosage form in single or divided form, the unit dose or unit dosage comprising (i) a therapeutically effective amount of a conjugate of the formula:, and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target 10 protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, independently, a hapten and (ii) a non-ionic surfactant.

[0055] Embodiment 4 relates to a method for treating an influenza infection in a host animal, the method comprising the step of administering to the host animal a composition comprising (i) a therapeutically effective amount of a conjugate of the formula: 15, and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0056] Embodiment 5 relates to the use of a composition in the manufacture of a 20 medicament for treating an influenza infection, the composition comprising (i) a therapeutically effective amount of a conjugate of the formula: , and pharmaceutically acceptable salts thereof wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L is a linker; and A1and A2are each, 25 independently, a hapten and (ii) a non-ionic surfactant.

[0057] Embodiment 6 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding embodiments comprising (i) a conjugate of the formula: - 8 -70849-04, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant. 5

[0058] Embodiment 7 relates to a pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments wherein T is a radical of the formula:.

[0059] Embodiment 8 relates to the pharmaceutical composition, unit dose, unit dosage 10 form, method, or use of any one of the preceding Embodiments wherein T is a radical of the formula:.

[0060] Embodiment 9 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments where L or L1, L2, and L3, 15 comprise a group of the formula:.

[0061] Embodiment 10 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments comprising (i) a conjugate of the formula: - 9 -70849-04, and diastereomers thereof, and (ii) a non-ionic surfactant.

[0062] Embodiment 11 relates to the pharmaceutical composition, unit dose, unit dosage 5 form, method, or use of any one of the preceding Embodiments comprising Compound 24 and a non-ionic surfactant.

[0063] Embodiment 12 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments wherein the non-ionic surfactant is n-dodecyl ^-D-maltoside (DDM). 10

[0064] Embodiment 13 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments comprising microcrystalline cellulose.

[0065] Embodiment 14 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments comprising carboxymethyl 15 cellulose.

[0066] Embodiment 15 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments comprising Avicel® RC 591.

[0067] Embodiment 16 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of any one of the preceding Embodiments further comprising one or 20 more carriers, diluents, excipients, or a combination of two or more thereof.

[0068] Embodiment 17 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of Embodiment 16 comprising a carrier.

[0069] Embodiment 18 relates to the pharmaceutical composition, unit dose, unit dosage form, method, or use of Embodiment 17 wherein the carrier is phosphate-buffered saline 25 (PBS).

[0070] Embodiment 19 relates to the pharmaceutical composition of any one of embodiments 1 to 18, wherein the pharmaceutical composition is not a solid.

[0071] Embodiment 20 relates to the pharmaceutical composition of any one of Embodiments 1 to 12 or 16 to 19, wherein the pharmaceutical composition does not comprise - 10 -70849-04 a polymer.

[0072] Embodiment 21 relates to the pharmaceutical composition of any one of Embodiments 1 to 12 or 16 to 20, wherein the pharmaceutical composition does not comprise a cellulose. 5

[0073] Embodiment 22 relates to the pharmaceutical composition of any one of Embodiments 1 to 21, wherein the pharmaceutical composition does not further comprise a cellulose derivative.

[0074] Embodiment 23 relates to the pharmaceutical composition of any one of Embodiments 1 to 22, wherein the pharmaceutical composition does not comprise a cellulose 10 derivative selected from the group consisting of hydroxy propyl methyl cellulose, methyl cellulose, cellulose acetate, ethyl cellulose, cellulose nitrate, and cellulose succinate.

[0075] Embodiment 24 relates to a method of treating influenza comprising administering to a patient in need thereof an effective amount of a pharmaceutical composition of any one of Embodiments 1 to 23. 15

[0076] Embodiment 25 relates to the method of Embodiment 24, wherein the influenza is Influenza A virus.

[0077] Embodiment 26 relates to the pharmaceutical composition of any one of Embodiments 1 to 24 for use as a medicament.

[0078] Embodiment 27 relates to a pharmaceutical composition of any one of Embodiments 20 1 to 24 for use in the treatment of influenza.

[0079] Embodiment 28 relates to a pharmaceutical composition of any one of Embodiments 1 to 24 for use in the treatment of Influenza A virus.

[0080] In another embodiment, A1is a rhamnose fragment.

[0081] In another embodiment, A2is a dinitrophenyl (DNP) fragment. 25

[0082] In many embodiments, the non-ionic surfactant is n-dodecyl ^-D-maltoside (DDM).

[0083] In many embodiments, the formulations described herein include one or more excipients, diluents, or combinations of two or more thereof. In another embodiment, the formulations described herein include one or more carriers.

[0084] In many embodiments, unit doses of the compounds and pharmaceutical 30 compositions containing one or more of the compounds are also described herein. The unit doses include a therapeutically effective amount of the one or more compounds for treating a host animal with an influenza infection. The unit doses are in single or divided form, and may correspond to a daily dosage amount, or adjusted to a periodic amount that is shorter, including for multiple daily doses, or longer, including weekly or monthly doses. It is to be - 11 -70849-04 understood that the compositions may include other components and / or ingredients, including, but not limited to, other therapeutically active compounds, and / or one or more carriers, vehicles, diluents, adjuvants, excipients, and the like, and combinations thereof.

[0085] In many embodiments, methods for treating host animals with an influenza infection 5 are also described herein, where the methods include administering one or more of the compounds and / or compositions described herein to a host animal with. In another embodiment, uses of the compounds and compositions in the manufacture of a medicament for treating host animals with an influenza infection are also described herein. In another embodiment, the methods, uses, and medicaments include a therapeutically effective amount 10 of the one or more compounds and / or compositions described herein for treating a host animal with an influenza infection.

[0086] In many embodiments, the pharmaceutical composition of the disclosure comprises Compound 24 and DDM. In these and other embodiments, such compositions are formulated as solutions for intranasal delivery to treat an influenza infection in a human. In some 15 embodiments, the amount of Compound 24 per dose is 30 mg, 300 mg, or between 30 mg and 300 mg. Treatment of influenza with such compositions may reduce viral load and / or influenza symptoms.

[0087] The synthesis of Compound 24 is described herein and is also set forth in WO2025 / 085664, the contents of which are incorporated herein in their entirety. 20

[0088] It is to be understood herein that the compounds, compositions, unit doses, and methods described herein may be used alone or in combination with other compounds useful for treating an influenza infection, including those compounds that may be therapeutically effective by the same or different modes of action. In addition, it is to be understood herein that the compositions comprising the compounds described herein may be used in 25 combination with other compounds and / or formulations thereof that are administered to treat other symptoms or complications of an influenza infection.

[0089] Additional illustrative excipients, include but are not limited to thickening agents, gel forming agents, viscosity modifiers, and the like, such as microcrystalline cellulose (MCC), carboxymethyl cellulose (CMC), and the like. An illustrative excipient is Avicel® 30 RC 591 comprising microcrystalline cellulose and carboxymethyl cellulose.

[0090] Conjugates described herein include a small molecule neuraminidase inhibitor covalently conjugated to haptens, such as DNP and rhamnose. Conjugates described herein utilize the neuraminidase inhibitor to both suppress viral budding from the host cells, and to bind to the surface of viral particles and virus infected cells, decorating them with haptens. - 12 -70849-04 The viral-bound haptens recruit naturally occurring antibodies, such as anti-DNP and anti- rhamnose antibodies, resulting in opsonization of the virus / virus-infected cell and immune- mediated clearance. The mechanism of action of compounds described herein differs from other neuraminidase inhibitors which are susceptible to resistance development via mutations 5 affecting enzymatic activity. The dual mechanism of action of the compound’s neuraminidase-targeted anti-influenza therapy holds promise for significantly reducing the time and severity of influenza-associated symptoms in clinical settings. Conjugates described herein employ that dual-mechanism immunotherapy that targets the viral surface for immune recognition, potentially hindering the emergence of resistance because mutations are less 10 likely to impede this binding compared with enzyme inhibition alone.

[0091] In another embodiment, compositions comprising a conjugate described herein and one or more excipients are described herein. Illustrative excipients, include but are not limited to surfactants, such as n-dodecyl ^-D-maltoside (DDM). Additional illustrative excipients, include but are not limited to thickening agents, gel forming agents, viscosity 15 modifiers, and the like. Additional illustrative excipients, include but are not limited to microcrystalline cellulose, carboxymethyl cellulose, and the like. An illustrative excipient is Avicel® RC 591.

[0092] In another embodiment, compositions are described herein that include DDM in the range from about 0.1% to about 1% by weight. In another embodiment, the compositions 20 include DDM in the range from about 0.2% to about 0.9%, from about 0.3% to about 0.8%, from about 0.4% to about 0.7%, or from about 0.5% to about 0.7%.

[0093] In another embodiment, compositions comprising a compound described herein, one or more excipients, and a carrier are described herein, Illustrative carriers include water, saline, buffered water, phosphate buffered saline, and the like. Illustrative carriers optionally 25 include addition agents, such as but not limited to potassium chloride, sodium hydroxide, hydrochloric acid, and combinations thereof for pH modification, and the like.

[0094] In another embodiment, the compositions described are configured for intranasal (IN) administration, optionally using a device loaded with the composition.

[0095] In another embodiment, the compositions described are configured for intravenous 30 (IV) administration.

[0096] In another embodiment, the compositions described are configured for subcutaneous (SC) administration.

[0097] In another embodiment, the therapeutically effective amount is in the range from about 1 mg to about 1,000 mg for treating a human. In another embodiment, the - 13 -70849-04 therapeutically effective amount is in the range from about 10 mg to about 900 mg, from about 20 mg to about 800 mg, from about 20 mg to about 700 mg, from about 20 mg to about 600 mg, from about 20 mg to about 500 mg, or from about 20 mg to about 400 mg.

[0098] In another embodiment, the therapeutically effective amount is in the range from 5 about 100 mg to about 1,000 mg for treating a human. In another embodiment, the therapeutically effective amount is in the range from about 100 mg to about 900 mg, from about 100 mg to about 800 mg, from about 100 mg to about 700 mg, from about 100 mg to about 600 mg, from about 100 mg to about 500 mg, or from about 100 mg to about 400 mg.

[0099] In another embodiment, the therapeutically effective amount is in the range from 10 about 200 mg to about 1,000 mg for treating a human. In another embodiment, the therapeutically effective amount is in the range from about 200 mg to about 900 mg, from about 200 mg to about 800 mg, from about 200 mg to about 700 mg, from about 200 mg to about 600 mg, from about 200 mg to about 500 mg, or from about 200 mg to about 400 mg.

[0100] In another embodiment, the therapeutically effective amount is in the range from 15 about 300 mg to about 1,000 mg for treating a human. In another embodiment, the therapeutically effective amount is in the range from about 300 mg to about 900 mg, from about 300 mg to about 800 mg, from about 300 mg to about 700 mg, from about 300 mg to about 600 mg, from about 300 mg to about 500 mg, or from about 300 mg to about 400 mg.

[0101] In another embodiment, compositions are described herein that include the 20 compound in the range from about 0.1% to about 60% by weight. In another embodiment, the compositions include the compound in the range from about 0.2% to about 60%, or from about 0.25% to about 55% by weight.

[0102] In another embodiment, compositions are described herein that include the compound in the range from about 10% to about 60% by weight. In another embodiment, the 25 compositions include the compound in the range from about 20% to about 60%, from about 30% to about 60%, or from about 40% to about 60% by weight.

[0103] In another embodiment, compositions are described herein that include the compound in the range from about 10% to about 55% by weight. In another embodiment, the compositions include the compound in the range from about 20% to about 55%, from about 30 30% to about 55%, or from about 40% to about 55% by weight.

[0104] In another embodiment, compositions described herein also include one or more preservatives, antibacterial agents, antifungal agents, and the like, and combinations thereof.

[0105] In another embodiment, compositions described herein are administered using a device, such as an Aptar Unidose nasal device. - 14 -70849-04

[0106] In another embodiment, methods are described herein where the compositions are administered for a total treatment duration of 1 day, and dosed either q.d. or b.i.d.

[0107] In another embodiment, the virus is influenza. In another embodiment, the virus is an H1N1 virus, an H3N2 virus, an H3N3 virus, or an oseltamivir-resistant virus. 5

[0108] A pharmaceutical composition comprising a conjugate of any of the embodiments recited herein, and optionally comprising one or more carriers, diluents, excipients, and the like, and combinations thereof.

[0109] A pharmaceutical composition comprising a conjugate of any of the embodiments recited herein, and optionally comprising one or more carriers, diluents, excipients, and the 10 like, and combinations thereof for use in treating a host animal having an influenza infection.

[0110] A unit dose comprising a conjugate of any of the embodiments recited herein, or a pharmaceutical composition thereof and optionally comprising one or more carriers, diluents, excipients, and the like, and combinations thereof, where the unit dose is in single or divided form, and includes a therapeutically effective amount of the compound for treating a host 15 animal having an influenza infection.

[0111] A method for treating a host animal having an influenza infection, the method comprising administering a therapeutically effective amount of a conjugate of any of the embodiments recited herein, or a pharmaceutical composition thereof and optionally comprising one or more carriers, diluents, excipients, and the like, and combinations thereof, 20 or a unit dose comprising any of the foregoing, in single or divided form, to the host animal.

[0112] Use of a conjugate of any of the embodiments recited herein, or a pharmaceutical composition thereof and optionally comprising one or more carriers, diluents, excipients, and the like, and combinations thereof, in the manufacture of a medicament, including a unit dose, in single or divided form, for treating a host animal having an influenza infection. 25

[0113] A kit comprising a conjugate, composition, or unit dose, of any one of the preceding embodiments; an optional carrier; an optional container for preparing a composition for administration comprising the conjugate or composition or unit dose and the optional carrier; and instructions for administering the conjugate or composition or unit dose or composition for administration to a host animal having an influenza infection. 30

[0114] The compositions and methods of the disclosure can be used for both human clinical medicine and veterinary applications. Thus, the host animal harboring the population of pathogenic cells and treated with the compounds described herein can be human or, in the case of veterinary applications, can be a laboratory, agricultural, domestic, or wild animal.

[0115] Unless otherwise indicated, the recitation of a numerical value necessarily reflects - 15 -70849-04 the relative precision of the numerical value. For example, the recitation of a number with a specified precision based on significant figures necessarily includes a range of values that would match that number after appropriate rounding. For example, the recitation of the number 1 with a single significant figure is understood to properly refer to a range of values 5 from 0.5 to 1.4. Similarly, the recitation of the number 1.0 with two significant figures is understood to properly refer to a range of values from 0.95 to 1.04. The relative precision of the numerical value can be further indicated by modifying with the term “about” to indicate that the modified number has lower precision.

[0116] The term “about” when used with numerical values or limits generally means that 10 the number is approximate and that, as recited, it is understood to include a range of values. For example, a real number that is recited with a single significant figure, would by definition include a so-called rounding range; the number about 5 would at the very least include the range 4.5-5.4, as each of those values rounds to 5. The same is to be understood for real numbers expressed with additional significant figures, where the corresponding rounding 15 range applies to the last significant figure. Integers are to be understood to at least include the values ±1 for single-digit numbers, ±10 for two-digit numbers, etc. Depending upon the context and the variable recited, the term “about” is also interpreted to contemplate a range based on a percentage of the recited number, such as about 5 construed to include 5 ±10% or 5 ±20%. Notwithstanding the foregoing, it is understood that the range of values, unless 20 otherwise indicated, should not be interpreted to include a negative range for a positively recited number, and vice-versa. In addition, depending up on the context, the recited number, unless otherwise indicated, should not be interpreted to include a value of zero when used in conjunction with an added component.

[0117] The term “therapeutically effective amount,” as used herein, refers to that amount of 25 active compound or pharmaceutical agent that elicits the biological or medicinal response in a tissue system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, which includes alleviation of the symptoms of the disease or disorder being treated. In one aspect, the therapeutically effective amount is that which may treat or alleviate the disease or symptoms of the disease at a reasonable benefit / risk ratio 30 applicable to any medical treatment. However, it is to be understood that the total daily usage of the compounds and compositions described herein may be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically-effective dose level for any particular patient will depend upon a variety of factors, including the disorder being treated and the severity of the disorder; activity of the specific compound - 16 -70849-04 employed; the specific composition employed; the age, body weight, general health, gender and diet of the patient: the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidentally with the specific compound employed; and like factors well 5 known to the researcher, veterinarian, medical doctor or other clinician of ordinary skill.

[0118] Illustrative formats for oral administration include tablets, capsules, elixirs, syrups, and the like.

[0119] Illustrative routes for parenteral administration include intravenous, intraarterial, intraperitoneal, epidural, intraurethral, intrasternal, intramuscular and subcutaneous, as well 10 as any other art recognized route of parenteral administration.

[0120] The terms “nasal administration” and / or “intranasal administration” refer to a route of administration where the compound or composition described herein in insufflated through the nose or into the nasal cavity. Nasal administration and / or intranasal administration may use the compound or composition in a variety of physical forms, including, but not limited to 15 powders, suspensions, gels, solutions, and the like. Nasal administration and / or intranasal administration may also use devices loaded with the compound or composition.

[0121] The compound and optionally one or more other therapeutic agents can be administered as a free compound or as a salt. When used in medicine the salts should be pharmaceutically acceptable, but non-pharmaceutically acceptable salts may conveniently be 20 used to prepare pharmaceutically acceptable salts thereof.

[0122] The conjugates hereof can be “deuterated,” meaning one or more hydrogen atoms can be replaced with deuterium. As deuterium and hydrogen have nearly the same physical properties, deuterium substitution is the smallest structural change that can be made. Deuteration is well known to those of ordinary skill in the art. 25

[0123] The conjugates, in some embodiments, can contain one or more asymmetric centers and thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that are defined, in terms of absolute stereochemistry, as (R) or (S) . In certain embodiments, the conjugate is of R-configuration. In certain embodiments, the conjugate is of S-configuration. Unless stated otherwise, it is intended that all stereoisomeric forms of the conjugates are 30 contemplated. When the conjugates contain alkene double bonds, and unless specified otherwise, it is intended that both E and Z geometric isomers (e.g., cis or trans) and / or optical isomers are included. In certain embodiments, for example, D and A of a conjugate are arranged in a relative cis orientation. In certain embodiments, D and A of a conjugate are arranged in a relative trans orientation. Likewise, all possible isomers, as well as their - 17 -70849-04 racemic and optically pure forms, and all tautomeric forms are also intended to be included. The term “geometric isomer” refers to E or Z geometric isomers (e.g., cis or trans) of an alkene double bond. The term “positional isomer” refers to structural isomers around a central ring, such as ortho-, meta-, and para- isomers around a benzene ring. 5

[0124] Further, in each of the foregoing and following embodiments, it is to be understood that the formulae include and represent not only all pharmaceutically acceptable salts of the conjugates, but also include hydrates and / or solvates of the conjugate formulae or salts thereof. Indeed, hydrates and solvates of the conjugates are also contemplated. The term “solvate” means a conjugate, or a salt thereof, that further includes a stoichiometric or non- 10 stoichiometric amount of solvent bound by non-covalent intermolecular forces. Where the solvent is water, the solvate is a hydrate.

[0125] Pharmaceutical compositions, methods of treatment, and uses of said pharmaceutical compositions of the disclosure may be made or performed with one or more of the compounds of WO2023 / 205669, which is incorporated herein by reference in its entirety and 15 WO2025 / 085664 also incorporated herein by reference in its entirety.

[0126] The conjugate compounds described herein may be formed from a ligand that is capable of targeting a protein of an influenza or virus-infected cell. In many embodiments, said protein is on the surface of an influenza or virus-infected cell, or is otherwise accessible from the surface of an influenza or virus-infected cell. The conjugates described herein may 20 also be formed from two or more haptens, each comprising an immune system responsive epitope or antigen. The conjugates described herein may also be formed from a polyvalent linker that covalently attaches the ligand to the two or more haptens. Described herein are numerous selections for each of the ligand, the haptens, and the linker. Each of the ligands and haptens described herein may be proteinaceous or small molecules. Each of the linkers 25 described herein may be proteinaceous or small molecules, or combinations thereof. It is to be understood that any ligand, any haptens, and any linker described herein may be combined to form the conjugates. In addition, the linkers themselves are formed from various building blocks, including single atoms, functional groups, and chemical fragments. It is to be understood that every combination of building blocks is described herein for forming the 30 linkers included in the conjugates.

[0127] In some embodiments, the conjugates have a dual mechanism of action, where the conjugate inhibits the virus, and also labels or decorates virus-infected cells for intervention by the immune system of the host animal, including humans. The conjugates elicit host - 18 -70849-04 animal immune response against the virus or virus-infected cells by recruiting antibodies in the host animal. Illustratively, the antibodies are endogenous.

[0128] Without being bound by theory, it is believed that once recruited, the anti-hapten antibodies bind to the hapten and activate the innate immune system against the target virus 5 and virus-infected cells. The haptens may be the same or different. In the conjugates where the haptens are the same, the immune system of the host animal may be multiplied. In the conjugates where the haptens are different, the immune system of the host animal may respond in multiple ways. The conjugates described herein provide a therapeutic delivery system for selectively or specifically delivering haptens to target virus and virus-infected 10 cells. In certain embodiments, the haptens are selected to activate the innate immune system of the subject to recruit immune cells and / or otherwise leverage the subject’s own immune system against the virus. The targeting ligand can selectively or specifically recognize a target protein or receptor, such as an envelope protein of a virus, which can be highly or exclusively expressed on the virus, the surface of an infected cell, or accessible from the 15 surface of an infected cell.

[0129] In other embodiments, the conjugate compound of Formula I can have fragments L2- A1and L3-A2bound to the same atom on L1. In some embodiments, the same atom is not a carbon atom. In some embodiments, the same atom is a nitrogen atom. Alternatively, the conjugate of Formula I can have fragments L2-A1and L3-A2bound to a different atom on L1. 20

[0130] The compounds, compositions, unit doses, and methods described herein are useful in treating Influenza A, Influenza B, and Avian Influenza. Illustrative strains of influenza that are treatable using the compounds, compositions, unit doses, and methods described herein include, but are not limited to, H1N1, H1N1pdm09, H3N2, and avian strains H5N1 and H7N9, and resistant strains, such as H1N1pdm09, oseltamivir-resistant, and H1N1pdm09, 25 baloxavir-resistant.

[0131] Without being bound by theory, it is believed the method can elicit an immune response leading to clearance of an antibody (Ab)-coated virus or an Ab-coated-virally infected cell via Ab-dependent cellular phagocytosis (ADCP), Ab-dependent cellular cytotoxicity (ADCC), and / or complement-dependent cytotoxicity (CDC) which works in 30 conjunction with the inhibition of viral budding by neuraminidase inhibition leading to viral eradication. The method for activating an immune response can further comprise administering to the subject autologous antibodies, allogeneic IgG antibodies, or human IVIG. In these and other embodiments, the subject may be further treated with anti-hapten antibodies. - 19 -70849-04

[0132] In many illustrative embodiments, T is a radical of a neuraminidase inhibitor. Illustrative neuraminidase inhibitors include, but are not limited to, sialic acid and analogs and derivatives thereof, zanamivir, peramivir, laninamivir, oseltamivir, 2,3-dehydro-2-deoxy- n-acetylneuraminic acid, and analogs and derivatives of the foregoing, such as compounds 5 disclosed in US 6340702, WO 1991 / 016320, WO 1996 / 026933, WO 1999 / 033781, and the like.

[0133] In many embodiments, the ligand is zanamivir:or an analog or derivative thereof. 10

[0134] It is to be understood that a radical may be formed on any atom of the foregoing to form the radical T.

[0135] In many embodiments, T is a radical of the formula:having any specific stereochemical configuration, or a having a mixture of two or more 15 stereochemical configurations.

[0136] In many embodiments, T is a radical of the formula:.

[0137] In many embodiments, the ligand is peramivir: - 20 -70849-04or an analog or derivative thereof, including compounds described in Chand et al. J Med Chem 44(25):4379-92 (2001) Bai et al. Viruses 13(624):1-13 (2021), and the like.

[0138] In many embodiments, T is a radical of the formula: 5.

[0139] In many embodiments, the ligand is an amino analog of peramivir:or an analog or derivative thereof.

[0140] In many embodiments, T is a radical of the formula: 10.

[0141] In many embodiments, the ligand is laninamivir:- 21 -70849-04 or an analog or derivative thereof.

[0142] In many embodiments, the ligand is a compound of the formula:or an analog or derivative thereof. 5

[0143] In many embodiments, the ligand is oseltamivir.

[0144] In many embodiments, the ligand is of the formula:wherein R is alkyl, H, or salt; R1 is NH2, NHCH2CH2OH, azido, guanidino, NHallyl, N(allyl)2, or a heterocyclyl group; and R2 is NH2 or acetamido. 10

[0145] In many embodiments, the ligand is of the formula:wherein R is Me, H, or salt; R1 is NH2 or guanidino; R2 is NH2 or acetamido; and R4 is alkyl (C-4 to C-14), and ether, acyl, and carbamoyl derivatives thereof.

[0146] In many embodiments, the ligand is of the formula: 15where R is Me or Et; R2 is H or OH; R1 is alkyl (primary and secondary, C-3 to C-10); and R3 is NH2 or optionally substituted guanidino.

[0147] In many embodiments, the ligand is of the formula: - 22 -70849-04wherein R is H, Me, Et or a salt; R1 is NH2, azido, or guanidino; R2 is C(O)CH3, C(O)CF3, or SO2Me; and R3 is alkyl (primary or secondary, C-1 to C-5), or CH2OMe.

[0148] In another illustrative embodiment, T is a radical of a hemagglutinin inhibitor. 5 Illustrative hemagglutinin inhibitors include, but are not limited to, flufirvitide 3, umifenovir, arbidol, tert-butyl hydroquinone, and the like.

[0149] In many embodiments, the ligand is of the formula:and analogs and derivatives thereof, including compounds described in Kitamura et al. PNAS 10 121(22):1-9 (2024), Bai et al. Viruses 13(624):1-13 (2021), and the like.

[0150] It is to be understood that a radical may be formed on any atom of any of the foregoing ligands to form the radical T.^

[0151] In many embodiments, T is a radical of flufirvitide 3 of the formula VEDTKIDLWSYNAELL (SEQ ID NO: 1). 15

[0152] In many embodiments, the ligand is cyclo(Ac-YWHKNKYVLTYSC)LFAAG- CONH2 (SEQ ID NO: 2), cyclo(Ac-YRWVWTSFFSEPYFVVC)G-CONH2 (SEQ ID NO: 3), cyclo(Ac-YLKIYWSKIHGLVSEWC)G- CONH2 (SEQ ID NO: 4), or cyclo(Ac- YVLFRWDHGTLATHWVC)G-CONH2 (SEQ ID NO: 5), including compounds described in Pascha et al. ACS Chem Biol 17:2425-36 (2022). 20

[0153] It is to be understood that radicals may be formed at the N-terminus, the C-terminus, or on an interior atom on the peptide chain to form the radical T. It is also to be understood that other radicals may be formed on a side chain of an amino acid to form the radical T.

[0154] The haptens described herein can each be bound by an antibody. After administration to a subject, each hapten (A1and A2) can be bound by an antibody. In certain embodiments, - 23 -70849-04 the two haptens, A1and A2can each be bound by a different antibody after administration to a subject. It is to be understood that any hapten, including peptide sequences, that elicit an immunological response in the host animal may be used to form the conjugates described herein. It is to be further understood an immunological response in the host animal may be 5 elicited or supplemented via vaccination as a co-therapy to the methods and uses described herein.

[0155] In another embodiment, A1 and A2 are each an independently selected radical of an antigen where for each antigen there is an endogenous antibody present in the host animal. Illustrative haptens include, but are not limited to, a rhamnose, including L-rhamnose, a 10 nitrophenyl, a nitrophenol, a nitroaniline, a dinitrophenyl (DNP), a dinitrophenol, a dinitroaniline, a trinitrophenyl (TNP), a trinitrophenol, a trinitroaniline, a chloronitrophenyl, a chloronitrophenol, a chloronitroaniline, an iodonitrophenyl, an iodonitrophenol, an iodonitroaniline, a nitrotyrosine, an hydroxynitrotyrosine, an aminonitrotyrosine, 4-hydroxy- 3-nitrophenyl acetic acid, an ^-galactosyl moiety, a sulfated Gal, compounds of the formulae: 15, a phosphorylcholine, a bacterial antigen, a viral antigen, and the like, and any combination of two or more of the foregoing.

[0156] In many embodiments, the hapten is selected from a dinitrophenyl (DNP), a dinitrophenol, and a dinitroaniline. In many embodiments, A1and / or A2is a radical of a 20 dinitrophenyl (DNP), a dinitrophenol, or a dinitroaniline, including radicals of the formulae:where L2or L3is attached at (*). - 24 -70849-04

[0157] In many embodiments, the hapten is selected from a rhamnose, including L-rhamnose. In many embodiments, A1and / or A2is a radical of a rhamnose, including L-rhamnose, and including a radicals of the formulae:5 where L2or L3is attached at (*).

[0158] In many embodiments, A1is a DNP radical and A2is a rhamnose radical, or vice versa. In many embodiments, A1is a DNP radical and A2is an L-rhamnose radical, or vice versa.

[0159] In another embodiment, neither A1nor A2comprises a fluorescein, such as FITC, and 10 the like.

[0160] As used herein, the term “linker” generally refers to a chain of atoms that connects two or more functional parts of a molecule to form a conjugate. Illustratively, the chain of atoms is selected from C, N, O, S, Si, and P, or C, N, O, S, and P, or C, N, O, and S. The chain of atoms covalently connects different functional capabilities of the conjugate. The 15 linker may have a wide variety of lengths, such as in the range from about 2 to about 100 atoms in the contiguous backbone. The atoms used in forming the linker may be combined in all chemically relevant ways, such as chains of carbon atoms forming alkylene, alkenylene, and alkynylene groups, and the like; chains of carbon and oxygen atoms forming ethers, polyoxyalkylene groups, or when combined with carbonyl groups forming esters and 20 carbonates, and the like; chains of carbon and nitrogen atoms forming amines, imines, polyamines, hydrazines, hydrazones, or when combined with carbonyl groups forming amides, ureas, semicarbazides, carbazides, and the like; chains of carbon, nitrogen, and oxygen atoms forming alkoxyamines, alkoxylamines, or when combined with carbonyl groups forming urethanes, amino acids, acyloxylamines, hydroxamic acids, and the like; and 25 many others. In addition, it is to be understood that the atoms forming the chain in each of the foregoing illustrative embodiments may be either saturated or unsaturated, thus forming single, double, or triple bonds, such that for example, alkanes, alkenes, alkynes, imines, and the like may be radicals that are included in the linker. In addition, it is to be understood that the atoms forming the linker may also be cyclized upon each other or be part of cyclic 30 structure to form divalent cyclic structures that form the linker, including cycloalkanes, cyclic ethers, cyclic amines, and other heterocycles, arylenes, heteroarylenes, and the like in the - 25 -70849-04 linker. In this latter arrangement, it is to be understood that the linker length may be defined by any pathway through the one or more cyclic structures. Illustratively, the linker length is defined by the shortest pathway through the each one of the cyclic structures. It is to be understood that the linkers may be optionally substituted at any one or more of the open 5 valences along the chain of atoms, such as optional substituents on any of the carbon, nitrogen, silicon, or phosphorus atoms. It is also to be understood that the linker may connect the two or more functional parts of a molecule to form a conjugate at any open valence, and it is not necessary that any of the two or more functional parts of a molecule forming the conjugate are attached at any apparent end of the linker. 10

[0161] In many embodiments, L1, L2, and L3each, independently comprises a chain of atoms from 3 atoms to about 60 atoms in length. In many embodiments, L1, L2, and L3each, independently comprises a chain of atoms from about 4 ^ to about 72 ^ in length. The chain of atoms are part of the backbone of the conjugate of Formula I. As used herein, the term “backbone” of the linker L refers to the shortest chain of contiguous 15 atoms forming a covalently bonded connection between T and L2, between T and L3, between A1and L1, or between A2and L1.

[0162] In many embodiments, L1, L2, or L3each, independently, comprise a chain of atoms at least 3 atoms in length, at least 7 atoms in length, at least 10 atoms in length, at least 14 atoms in length, or at least 20 atoms in length. In many embodiments, L1, L2, or 20 L3each, independently, have a chain of between 3 and 7 atoms in length, between 7 and 10 atoms in length, between 10 and 14 atoms in length, between 14 and 20 atoms in length, between 20 and 30 atoms in length, between 30 and 40 atoms in length, between 40 and 50 atoms in length, or between 50 and 60 atoms in length. In many embodiments, L1, L2, or L3each, independently, comprise a chain of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 25 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60 atoms in length. As used herein, the term “between” is inclusive of the endpoints meaning that between 3 and 5 atoms in a chain length includes 3 atoms, 4 atoms, and 5 atoms. 30

[0163] It is to be understood that while both L2and L3are covalently attached to L1, both L2and L3may be attached to the same atom of L1, or L2and L3may each be attached to different atoms of L1. In another embodiment, L2and L3are attached to the same atom on L1where that atom is not a carbon atom.

[0164] In many embodiments, L1, L2, or L3can each, independently, comprise one or more - 26 -70849-04 amino acid or peptide residues.

[0165] As used herein, the term “amino acid” refers generally to beta, gamma, and longer amino acids, and including cyclic groups, that have both an amino group and an acid group from each of which a radical can be formed. Illustrative acyclic amino acids include the 5 formula: -N(R)-(CR^R^)q-C(O)- where R is hydrogen, alkyl, acyl, or a suitable nitrogen protecting group, R^ and R^ are hydrogen or a substituent, each of which is independently selected in each occurrence, and q is an integer such as 1, 2, 3, 4, or 5. Illustratively, R^ and / or R^ independently correspond to, 10 but are not limited to, hydrogen or the side chains present on naturally occurring amino acids, such as methyl, benzyl, hydroxymethyl, thiomethyl, carboxyl, carboxylmethyl, guanidinopropyl, and the like, and derivatives and protected derivatives thereof. The above- described formula includes all stereoisomeric variations. For example, the amino acid may be selected from asparagine, aspartic acid, cysteine, glutamic acid, lysine, glutamine, 15 arginine, serine, ornithine, threonine, and the like.

[0166] For example, L1, L2, or L3can each, independently, comprise one or more lysine residues, each of which is independently optionally substituted. For example, L1can comprise a lysine residue of the formula:20 wherein A1or A2is attached to the lysine residue via a linker. In another embodiment, the lysine residue is L-Lys. In one example, L1comprises at least one lysine residue, such as L- Lys.

[0167] In many embodiments, L1, L2, or L3can each, independently, comprise a polyethylene glycoln (PEGn) moiety, wherein n is between, and including 1 to 36. In 25 many embodiments, a linker comprises one or more PEG moieties where all carbon and oxygen atoms of the one or more PEG moieties are part of the backbone of the linker.

[0168] In many embodiments, L1, L2, or L3can each, independently, comprise one or more alkyl groups.

[0169] In many embodiments, L1, L2, or L3can each, independently, comprise one or 30 more or sugar moieties, glycan residues, or peptidoglycan residues. - 27 -70849-04

[0170] It is to be understood that the bonds connecting atoms in the chain can be either saturated or unsaturated, such that for example, alkanes, alkenes, alkynes, cycloalkanes, arylenes, imides, and the like can be divalent radicals that are included in L. In each of the foregoing, the atoms of L in the chain can be substituted or unsubstituted. 5

[0171] In addition, it is to be understood that the atoms forming the linker may also be cyclized to form saturated or unsaturated divalent cyclic radicals in the linker, such as radicals of the formulae:wherein each X1is independently CH2, NR’, or O wherein R’ is alkyl or hydrogen and 10 each X2is independently S, O, N, NH, CR” wherein R” is alkyl or hydrogen. Examples of such radicals include:

[0172] In some embodiments, L1, L2, or L3comprises suitable substituents that change the hydrophobicity or hydrophilicity of the linker. Illustrative hydrophobic groups 15 include alkyl, cycloalkyl, aryl, and arylalkyl, each of which is optionally substituted.

[0173] L1, L2, or L3can each, independently, comprise alkylene-amino-alkylenecarbonyl, alkylene-thio-(carbonylalkylsuccinimid-3-yl) moieties, including the following formulae:wherein x and y are each independently 1, 2, 3, 4, or 5, where the asterisk identifies 20 points of attachment either to other linker fragments of T or A1or A2.

[0174] Additional examples of groups which may be present in the linkers include 1- alkylsuccinimid-3-yl, carbonyl, thionocarbonyl, alkyl, cycloalkyl, alkylcycloalkyl, - 28 -70849-04 alkylcarbonyl, cycloalkylcarbonyl, carbonylalkylcarbonyl, 1-alkylsuccinimid-3-yl, 1- (carbonylalkyl)succinimid-3-yl, alkylsulfoxyl, sulfonylalkyl, alkylsulfoxylalkyl, alkylsulfonylalkyl, carbonyltetrahydro-2H-pyranyl, carbonyltetrahydrofuranyl, 1- (carbonyltetrahydro-2H-pyranyl)succinimid-3-yl, and 1- 5 (carbonyltetrahydrofuranyl)succinimid-3-yl, wherein each group can be substituted or unsubstituted. In some embodiments, one or more of the aforementioned groups can be used in combination (or more than once) (e.g., -alkyl-C(O)-alkyl) and may further comprise an additional nitrogen (e.g., alkyl-C(O)-NH-, -NH-alkyl-C(O)- or -NH-alkyl-), oxygen (e.g., -alkyl-O-alkyl-) or sulfur (e.g., -alkyl-S-alkyl-). Examples include 10 alkylcarbonyl, cycloalkylcarbonyl, carbonylalkylcarbonyl, 1-(carbonylalkyl)succinimid- 3-yl, and succinimid-3-ylthiol, wherein each group can be substituted or unsubstituted.

[0175] In some embodiments, L1, L2, or L3can be formed via click chemistry or be click chemistry-derived. For example, L1, L2, or L3can be derived from copper-catalyzed azide-alkyne cycloaddition (CuAAC), strain promoted azide-alkyne cycloaddition 15 (SPAAC), inverse electron demand Diels-Alder reaction (IEDDA), and Staudinger ligation (SL). For example, T can be a moiety of the formula T-N3. T-N3 can then be reacted with an alkyne as shown in the following scheme:where the wavy line connected to T and to A1 / A2represents a linker between T and A1 / A220 and the groups to which they are attached.

[0176] In other embodiments, L1, L2, or L3can include:where x is an integer from 0 to 50 and y is an integer from 0 to 50. 25

[0177] In other embodiments, L1, L2, or L3can include: - 29 -70849-04wherein each of R2and R3is independently H or C1-6alkyl; and z is an integer from 1 to 8.

[0178] In other embodiments, L1, L2, or L3can include an amide, ester, urea, carbonate, 5 carbamate, amino acid, amine, ether, alkyl, alkene, alkyne, heteroalkyl, cycloalkyl, aryl, heterocycloalkyl, heteroaryl, carbohydrate, glycan, peptidoglycan, polypeptide, or any combination thereof. In some embodiments, L1, L2, or L3can include a glycosylated amino acid. In some embodiments, L1, L2, or L3can include one or more monosaccharide, disaccharide, polysaccharide, glycan, or peptidoglycan. In some 10 embodiments, L1, L2, and L3do not comprise a glycan. In some embodiments, L1, L2, and L3do not comprise a sugar.

[0179] In some embodiments, L1, L2, or L3can include a rigid functionality such as an oligoproline or oligopiperidine.

[0180] In some embodiments, an oligoproline or oligopiperidine has about two up to and 15 including about fifty, about two to about forty, about two to about thirty, about two to about twenty, about two to about fifteen, about two to about ten, or about two to about six repeating units (e.g., prolines or piperidines).

[0181] In some embodiments, L1, L2, or L3can comprise (–CH2CH2-O-)n, where n is an integer between and including 1 and 36 (e.g., 1 to 2, 2 to 6, 3 to 8, 6 to 12, and 4 to 10) a 20 peptide, an alkylamido group (e.g., C(O)N(H)C2-C18 alkyl- or C2-C18 alkyl-C(O)N(H)-), an alkylamidoalkyl group (e.g., a C2-C18alkyl-C(O)N(C2-C18alkyl)2or a C2-C18alkyl- C(O)N(H)-C2-C18alkyl group, such as a -CH2CH2C(O)N(CH2CH2)2or a - CH2CH2C(O)N(H)(CH2CH2)- group), or a combination of two or more of the foregoing.

[0182] In some embodiments, L1, L2, or L3can comprise: 25wherein m is an integer from 0 to 20, such as from 1 to 20, 0 to 15, 1 to 10, 2 to 10, 2 to 8, or 3 to 9. For example, m can be 0 or 1. Or m can be 5 or 6. Or m can be 7 or 8. In some embodiments, L1, L2, or L3can comprise: - 30 -70849-04wherein p and q are each, independently, an integer from 0 to 20, such as from 1 to 20, 0 to 15, 1 to 10, 2 to 10, 2 to 8, or 3 to 9. For example, p can be 2 or 3. For example, q can be 2 or 3. In some embodiments, L1, L2, or L3can comprise: 5wherein d is an integer from 0 to 20, such as from 1 to 20, 0 to 15, 1 to 10, 2 to 10, 2 to 8, or 3 to 9. For example, d can be 1, 2, or 3.

[0183] In some embodiments, L1, L2, and L3taken together can comprise: , 10such as wherein m, p, d, and q are each, independently, an integer from 0 to 20, such as from 1 to 20, 0 to 15, 1 to 10, 2 to 10, 2 to 8 or 3 to 9. For example, m can be 0 or 1. Or m can be 5 or 6. Or m can be 7 or 8. For example, p can be 2 or 3. For example, q can be 2 or 3. For 15 example, d can be 1, 2 or 3.

[0184] In some embodiments, L1, L2, and L3taken together can comprise: - 31 -70849-04.

[0185] In another embodiment, the following compounds are described: 5- 32 -70849-04.

[0186] In many embodiments, the target protein can be an envelope protein of an influenza 5 or an influenza envelope protein on the surface of a virus-infected cell. In many embodiments, the target protein can be influenza neuraminidase or influenza hemagglutinin.

[0187] In many embodiments, a solution formulation comprising Compound 24, N- Dodecyl-Beta-D-Maltoside and phosphate buffered saline is provided. In these and other embodiments, said formulations are used to treat influenza in human patients. In many 10 embodiments, said solutions are delivered intranasally. The dosage strengths of such formulations may be, for example, 2.5 mg / mL or 250 mg / mL and all values in between. In many embodiments, a single dose is provided. The strength of such dose includes such amounts of the formulation that 30 mg of Compound 24, 100 mg of Compound 24, or 300 mg of Compound 24 are delivered in such said dose. Other delivered amounts of 15 Compound 24 include between 10 mg and 500 mg, or between 20 g and 100 mg, or between 20 mg and 50 mg, or between 20 mg and 40 mg, or between 25 mg and 35 mg, or between 80 mg and 120 mg, or between 90 mg and 110 mg, or between 95 mg and 105 mg, or between 200 mg and 400 mg, or between 250 mg and 350 mg, or between 275 mg and 325 mg, or between 290 mg and 310 mg. 20

[0188] The following examples further illustrate specific embodiments of the present disclosure^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ to limit the scope of the claimed invention. Unless otherwise indicated, all starting compounds, reagents, and solvents described in the following examples are obtainable from commercial suppliers. - 33 -70849-04 EXAMPLES

[0189] The following examples serve to further illustrate the invention described herein. The examples are illustrative of the many embodiments of the invention and are not to be 5 construed as limiting the scope of the invention in any way. LIST OF ABBREVIATIONS- 34 -70849-04

[0190] General. Unless otherwise indicated, all starting compounds and reagents are commercially available. Unless otherwise indicated, reactions are performed under an - 35 -70849-04 ambient atmosphere, and at ambient temperature and pressure, and reaction progress is monitored by TLC, LCMS, or both. Unless otherwise indicated, solutions are concentrated and compounds are isolated by rotary evaporation under reduced pressure, under high vacuum, or both. 5 COMPOUND EXAMPLES

[0191] EXAMPLE 1. Compound 3 (FIG.5): To a solution of Compounds 1 (0.5 g, 2.47 mmol) and 2 (0.33 g, 2.47 mmol) (both commercially available) dissolved in ethyl alcohol (25 mL) was added triethylamine (1.38 mL, 9.87 mmol). The reaction mixture was heated to 10 55 ºC for 16 hours and reaction progress was monitored by LC-MS. After completion of reaction was confirmed by disappearance of one of the starting materials, i.e., dinitrobenzene, the reaction mixture was cooled and concentrated under reduced pressure. The crude mixture was purified by flash column chromatography on a Teledyne CombiFlash Rf+Lumen (silica- gel, 12 g column, 0-20% methanol in dichloromethane) to yield Compound 3 as a yellow 15 solid, yield, 90%). LC-MS [M+H]+= 300.24. Additional details are described in Chemistry - An Asian Journal (2012), 7, (2), 272-276.

[0192] EXAMPLE 2. Compound 5: To a solution of 3-(2-((2,4- dinitrophenyl)amino)ethoxy)propanoic acid (Compound 3, 0.1 g, 0.33 mmol) in dimethyl sulfoxide (2 mL) was added 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5- 20 b]pyridinium 3-oxid hexafluorophosphate, (0.11 g, 0.28 mmol, 0.85 equiv.) followed by N,N’-diisopropylethyl amine (0.29 mL, 1.67 mmol, 5.0 equiv.) under argon atmosphere and stirred for 10 min at room temperature. Compound 4 (0.11 g, 0.27 mmol, 0.8 equiv.) was added to the reaction mixture and stirred for 2-3 hours at room temperature. Progress of the reaction was monitored by LC-MS. After completion of the reaction was confirmed by LC- 25 MS, the reaction mixture quenched by adding water and extracting with ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The resulting crude was purified by silica-gel (4 g) column chromatography on Teledyne CombiFlash Rf+ Lumen (0-10% methanol in dichloromethane) and fractions were analysed by LC-MS. The solvent evaporated from combined pure 30 fractions using a rota-evaporator under reduced vacuum and Compound 5 was isolated in 70% yield. LC-MS [M+H]+= 650.67.

[0193] EXAMPLE 3. Compound 7 (FIG.6): Compound 6 (1.0 g, 5.49 mmol) (commercially available) was dissolved in 9.2 mL of anhydrous pyridine. The solution was stirred in an ice bath and purged with nitrogen prior to the dropwise addition of acetic - 36 -70849-04 anhydride (4.15 mL, 43.92 mmol, 8.0 equiv.) for 15 minutes by maintaining the internal temperature below 10 ºC. The reaction allowed to warm to room temperature slowly in 2 hours and progress of the reaction was monitored via TLC (Hexane / EtOAc, 65:35) and LC- MS, indicated complete consumption of ^-L-rhamnose monohydrate after 20 hours of 5 reaction under an inert atmosphere. The reaction mixture was poured into ethyl acetate and extracted twice with 1.0 M HCl. The combined organic layers were washed with saturated sodium carbonate solution, water and brine and dried over anhydrous sodium sulfate, and concentrated under vacuum. The resulting crude product, Compound 7 (yield, 98%), was used in the next step. LC-MS [M+H]+= 333.32 and / or LC-MS [M+H2O] = 350.32. 10

[0194] EXAMPLE 4. Compound 9: To a solution of Compound 7 (0.50 g, 1.50 mmol) in dichloromethane (DCM, 7.5 mL) was added H2N-PEG4-OH (Compound 8, 0.35 g, 1.81 mmol, 1.2 equiv.) (commercially available) under an inert atmosphere. The reaction flask was placed in an ice bath, and boron trifluoride diethyletherate (0.56 mL, 4.51 mmol, 3.0 equiv.) was added dropwise over 30 min at 4 ºC. The reaction mixture stirred at ice bath temperature 15 for 2 hours before the reaction was allowed to warm to room temperature. The progress of the reaction was monitored by TLC (Hexane / EtOAc, 30:70, Rf = 0.30) and LC-MS indicated complete consumption of 1,2,3,4-tetra-O-acetyl-^-L-rhamnose after 16 h of reaction. The reaction mixture was poured into ice water and extracted with DCM (3x10 mL). The combined organic layers were washed twice with saturated sodium bicarbonate solution, 20 water, brine and dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting crude was purified by silica-gel (12 g) column chromatography on Teledyne CombiFlash Rf+ Lumen (0-10% methanol in dichloromethane) and Compound 9 was isolated, yield, 90%. LC-MS [M+H]+= 466.51. Additional details are described in Biomacromolecules (2020), 21, 793−802. 25

[0195] EXAMPLE 5. Compound 10 (FIG.5): To a solution of Compound 5 (0.06 g, 0.09 mmol) and 9 (0.04 g, 0.09 mmol, 1.0 equiv.) in dimethyl sulfoxide (1.5 mL) was added benzotriazole-1-yl-oxy-tris-pyrrolidino-phosphonium hexafluorophosphate (0.05 g, 0.10 mmol, 1.1 equiv.) followed by N,N-diisopropylethyl amine (DIPEA, 0.081 mL, 0.46 mmol, 5.0 equiv.) under argon atmosphere at room temperature. Progress of the reaction monitored 30 by LC / MS. After completion of the reaction confirmed by LC-MS, the reaction mixture quenched by adding water and extracting with ethyl acetate. The combined organic layers washed with brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The resulting crude was purified by silica gel (4 g) column chromatography on Teledyne CombiFlash Rf+ Lumen (0-10% MeOH in dichloromethane) and Compound 10 was isolated - 37 -70849-04 in 93% yield. LC-MS [M+H]+= 1098.15.

[0196] EXAMPLE 6. Compound 11: To Compound 10 (0.01 g, 0.01 mmol) in dry dichloromethane (0.2 ml) was added diethylamine (DEA) (100µL) under argon at room temperature. The solution stirred for 1 hour at r.t. until the reaction was complete as 5 demonstrated by LC-MS. The DEA was removed by rotary evaporation under reduced pressure and the crude product precipitated in diethyl ether to give as a yellow solid (Compound 11) with a quantitative yield and was used for next step without further purification. LC-MS [M+H]+= 875.91.

[0197] EXAMPLE 7. Compound 13: To Compound 12 (5g, 11.0 mmol) (commercially 10 available) in tetrahydrofuran (THF, 40mL) was added triphenylphosphine (3.67g, 14mmol, 1.27 equiv.), and the resulting solution was stirred at r.t. for 12 hours. Subsequently, water (10mL) was added, and the solution was stirred at r.t. for another 2-4 hours. The reaction mixture was diluted and extracted with EtOAc (2x30 mL), followed by DCM (3x25 mL). The combined organic layers were washed with saturated aq. NaCl separately, dried over 15 anhydrous sodium sulfate, and concentrated under vacuum. The resulting crude product was purified by silica-gel (24 g) flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (0-100% EtOAc in hexanes) to give Compound 13 as a yellow powder. Compound 13 was isolated, 2.89g, yield, 61 %. LC-MS [M+H]+= 431.42. The starting material, Compound 12, was purchased from commercial sources. 20

[0198] EXAMPLE 8. Compound 15: To a solution of Compound 13 (2.74 g, 6.37 mmol) and N,N’-bis(tertbutoxycarbonyl)-1H-pyrazole-1-carboxamidine (Compound 14, CAS number, 152120-54-2, Sigma-Aldrich, 2.57 g, 8.28 mmol, 1.30 equiv.) dissolved in THF (20 mL) was added triethylamine (1.5 mL). The reaction mixture was stirred overnight at r.t. and progress of the reaction was monitored by LC / MS. After completion of the reaction, 25 quenched with water, diluted and extracted with EtOAc (3x20 mL). The combined organics were washed with saturated brine solution, followed by dried over anhydrous sodium sulfate (anhy. Na2SO4) and evaporated under vacuum. The resulting crude product purified by flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 24 g column, 0- 100% EtOAc in hexanes) to give Compound 15 as a white solid (4.14 g, 97 %). LC-MS 30 [M+H]+= 673.70.

[0199] EXAMPLE 9. Compound 17: 0.5 M sodium methoxide in methanol (2.9mL, 0.5M, 1.414mmol) was added to a stirred solution of Compound 15 (4.225g, 6.281mmol) in anhydrous methanol (70mL). The reaction mixture was then stirred for 1 hour. Dowex 50XW8 (H+) resin added to the reaction mixture to lower the pH ~3 and filtered, washed with - 38 -70849-04 methanol and concentrated under reduced pressure to lead compound, Compound 16, and was used in the next step without further purification. LC-MS [M+H]+= 547.58.

[0200] To Compound 16 in anhydrous acetone (70mL) was added 2,2-dimethoxypropane (7.7mL, 6.54g, 62.81mmol, 10 equiv.), followed by p-toluenesulfonic acid (120mg, 5 0.628mmol, 0.1 equiv.), and the resulting mixture was stirred overnight at room temperature. The reaction mixture was then concentrated and purified by flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 12 g column, 0-100% EtOAc in hexanes) to give Compound 17 as a white solid, product isolated 2.4g and yield, 65 %. LC-MS [M+H]+= 587.64. 10

[0201] EXAMPLE 10. Compound 19: To a solution of Compounds 17 (1.46 g, 2.49 mmol) and 18 (3.51 g, 17.43 mmol) (commercially available) in pyridine (30 mL) was added DMAP (2.13 g, 17.43 mmol). The reaction mixture was stirred overnight at r.t. and progress of the reaction followed by LC / MS. After completion of the reaction confirmed by LC / MS by disappearance of Compound 17, the reaction mixture is diluted and extracted with EtOAc 15 (3x 25 mL). The combined organic layer was then washed with water, brine and dried over anhydrous Na2SO4 then concentrated and purified by flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 24 g column, 0-100% EtOAc in hexanes) to give Compound 19 as a white solid (1.62 g, 87%). LC-MS [M+H]+= 752.45.

[0202] EXAMPLE 11. Compound 21: To Compound 19 (0.168 g, 0.223 mmol), in 20 tetrahydrofuran (THF, 1.1 mL) was added Compound 20 (0.079 g, 0.223 mmol, 1.0 equiv.) (commercially available) followed by N,N’-diisopropylethyl amine (DIPEA, 0.1 mL, 0.56 mmol, 2.5 equiv.) at r.t. under argon and stirred for 12 hours. Progress of the reaction was monitored by TLC and LC / MS. After completion of the reaction was confirmed by LC / MS by the complete disappearance of Compound 19, the reaction was diluted and extracted with 25 EtOAc (3x 25 mL). The combined organic layers were then washed with water, brine and dried over anhydrous Na2SO4 then concentrated under vacuum. The crude product was purified by flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 12 g column, 0-10% MeOH in DCM) to give Compound 21 as a white solid (0.205 g, 90 %). LC-MS [M+H]+= 967.06. 30

[0203] EXAMPLE 12. Compound 22: To a solution of Compound 21 (0.025 g, 0.026 mmol) in dichloromethane:dimethyl sulfoxide (10:1, 0.3 mL) was added 1- [bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate, (HATU, 0.01g, 0.026 mmol, 1.0 equiv.) followed by N,N’- diisopropylethyl amine (0.012 µL, 0.065 mmol, 2.5 equiv.) under argon atmosphere and - 39 -70849-04 stirred for 3-5 min at room temperature. Compound 11 (0.023 g, 0.026 mmol, 1.0 equiv.) in dichloromethane (0.2 mL) was added to the reaction mixture and stirred for 2-3 hours at room temperature. Progress of the reaction was monitored by LC-MS. After completion of the reaction was confirmed by LC-MS, the solvent evaporated, and the resulting crude was 5 purified by silica-gel (4 g) column chromatography on Teledyne CombiFlash Rf+ Lumen (0- 10% methanol in dichloromethane) and fractions were analysed by LC-MS. The solvent evaporated from combined pure fractions using rotaevaporator under reduced pressure and product (Compound 22) was isolated in 61% yield. LC-MS [M+H]+= 1822.94.

[0204] EXAMPLE 13. Compound 24: Compound 24 is prepared by deprotection of 10 Compound 22. It is understood that the deprotection of Compound 22 may be accomplished by initial removal of the Boc and ketal protecting groups using TFA in DCM, followed by deprotection of the methyl ester and acetyl ester protecting groups using LiOH^H2O in MeOH. Alternatively, the deprotection of Compound 22 may be accomplished by initial removal of the methyl ester and acetyl ester protecting groups using 15 NaOMe in MeOH, followed by deprotection of the Boc and ketal protecting groups using TFA in DCM, as follows. Compound 22 (38 mg, 0.021 mmol) was dissolved in methanol (0.5 mL) and treated drop wise with 0.5 M sodium methoxide in methanol (190 µL). The reaction mixture stirred at r.t. for 1 hour at which time LC-MS analysis revealed that hydrolysis of methyl ester as well as -OAc groups were completed. The reaction mixture was 20 neutralized by adding Dowex® 50WX8 (H+) resin, filtered, and concentrated under reduced pressure. The crude product (Compound 23) was used directly for the next step without further purification. LC-MS analysis revealed with multiple products, i.e., [M+H]+= 1683.89, 1642 (loss of acetonide) and 1542 (loss of –boc).

[0205] To the crude compound, Compound 23, in dichloromethane (DCM, 0.8 mL) and 25 trifluoroacetic acid (TFA, 0.8 mL) was added at ice-cold temperature. The reaction mixture was stirred for 15 min at r.t. and LC-MS indicated the reaction was complete. TFA was removed by rotary evaporation under reduced pressure and washed with cold diethyl ether. The crude product purified by prep-HPLC (UPLC) on a C18 column (5-95% B over 60 min, flow 7 mL / min; B: acetonitrile; A: 20 mM NH4OAc, pH 7 buffer, UV @ 360 nm and 220 30 nm) to afford Compound 24 and yield, 42 %. Purity: 95% by LC-MS [M + H]+= 1443.83.

[0206] EXAMPLE 14. (2R,3R,4S)-3-acetamido-2-((38R,39R)-25-(18-((2,4- dinitrophenyl)amino)-13-oxo-3,6,9,16-tetraoxa-12-azaoctadecyl)-39,40-dihydroxy- 13,26,36-trioxo-1-(((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran- - 40 -70849-04 2-yl)oxy)-3,6,9,16,19,22,29,32,37-nonaoxa-12,25,35-triazatetracontan-38-yl)-4- guanidino-3,4-dihydro-2H-pyran-6-carboxylic acid (Compound 42): 5.

[0207] Compound 3:To a stirred solution of Compound 1 (Angene, 1.0 g, 1.91 mmol) and Compound 2 (1.07 g, 2.03 mmol) in DMF (15.0 mL) HATU (0.034 g, 0.09 mmol) was added at 0 °C. After 10 min ethylbis(propan-2-yl)amine (GLR, 1.77 mL, 9.57 mmol) was 10 added dropwise to the reaction mixture at 0 °C. Cooling was discontinued and the mixture was stirred for 12 h. After reaction completion, the reaction mixture was concentrated, and the remainder was purified by silica gel column chromatography eluting in 5% MeOH / DCM to afford Compound 3 as a yellowish liquid. Yield: 1.20 g, 64.65 %; LCMS (ELSD) m / z 970.60 [M+1]+. 15

[0208] Compound 4: To a solution of Compound 3 (1.0 g, 1.03 mmol) in MeOH (50.0 mL), 10% Palladium on carbon (Johnson Matthey, 1.00 g) was added and stirred under an - 41 -70849-04 hydrogen atmosphere for 6 h. After reaction completion, the reaction mixture was filtered through a celite bed, washed with MeOH and the filtrate was evaporated to dryness. The remainder was triturated with diethyl ether to afford tert-butyl Compound 4 as a pale yellow viscous liquid. Yield: (0.80 g, 82.2 %); LCMS (ELSD) m / z 944.65 [M+1]+. 5

[0209] Compound 6: Compound 6 was prepared using the same procedure to make Compound 3 in this Example. Compound 6 was made from Compound 5 (0.11 g, 0.37 mmol) and Compound 4 (0.35 g, 0.37 mmol) in DMF (10.0 mL), and HATU (0.15 g, 0.40 mmol) and ethylbis(propan-2-yl)amine (0.34 mL, 1.85 mmol). After reaction completion, the reaction mixture was concentrated and the remainder was purified by silica gel column 10 chromatography eluting in 10% MeOH / DCM to afford Compound 6 as a yellowish liquid. Yield: 0.20 g, 44.03 %; LCMS (ESI) m / z 1225.30 [M+1]+.

[0210] Compound 7: To a stirred solution of Compound 6 (0.31 g, 0.25 mmol), in anhydrous DCM (5.0 mL), TFA (3.0 mL) was added at 0 °C. Cooling was discontinued and the reaction mixture was stirred for 2 h. After reaction completion, the reaction mixture was 15 evaporated to Compound 7 as a light yellow liquid which was used without further purification. Yield: 0.22 g; LCMS (ESI) m / z 1125.10 [M+1]+.

[0211] Compound 8 was prepared as described in Carbohydrate Research, 342 (2007) 1636- 1650).

[0212] Compound 10: To a flask containing Compound 8 (0.21 g, 0.28 mmol) in dry 20 THF (5 ml) was added DIPEA (GLR, 0.26 ml, 1.44 mmol) dropwise at 25-30°C under a N2atmosphere. After 5 mins, Compound 9 (Angene, 56 mg, 0.31 mmol) in dry THF (2 ml) was added to the reaction mixture and the resulting suspension was stirred for another 24 h at 25- 30°C. Progress of the reaction was monitored by TLC and LCMS. After reaction completion, the reaction mixture was concentrated and the remainder was purified by column 25 chromatography eluting in 10% MeOH / DCM to afford Compound 10 as an off white solid. Yield: 0.16 g, 70.05 %; LCMS (ESI) m / z 790.10 [M+1]+.

[0213] ^Compound 11: Compound 11 was prepared using the same procedure to make Compound 3 in this Example. Compound 11 was made from Compound 10 (0.11 g, 0.14 mmol) and Compound 7 (0.17 g, 0.15 mmol) in DMF (5.0 mL), and HATU (0.08 g, 30 0.15mmol) and ethylbis(propan-2-yl)amine (GLR, 0.13 mL, 0.70 mmol). After reaction completion, the reaction mixture was concentrated, and the remainder was purified by silica gel column chromatography eluting in 10% MeOH / DCM to afford Compound 11 as a yellowish liquid. Yield: 0.12 g, 45.42 %; LCMS (ESI) m / z 1896.00 [M+1]+. - 42 -70849-04

[0214] Compound 42: To a stirred solution of Compound 11 (0.11 g, 0.06 mmol) in THF (3 mL) and MeOH (1 mL) was added a 1.0 M solution of sodium hydroxide (0.1 mL) at 25-30 °C over 10 mins. An homogeneous solution was observed and stirred for 4 h at 25-30 °C. Completion of the reaction was confirmed by TLC and LCMS and the reaction mixture pH 5 was slowly adjusted to pH 7, by using Dowex 50XW8 (H+) resin. The reaction mixture was filtered through celite-bed and evaporated. To the stirred solution of the remainder in anhydrous DCM (3.0 mL), TFA (1.0 mL) was added at 0 °C and the reaction mixture was stirred at 15 °C for 2 h. After reaction completion, the solvent was evaporated, and the remainder was purified by prep HPLC using water / ACN in 0.1% TFA to afford Compound 10 42 as a yellowish solid. Yield: 0.015 g, 37.07 %; LCMS (ESI) m / z 1516.35 [M+1]+.1H NMR (400 MHz, DMSO-d6): 8.86 (d, J = 2.8 Hz, 1H), 8.82 (brs, 1H), 8.25 (dd, J = 9.2 & 2.4 Hz, 1H), 7.93 (m, 2H), 7.86 (d, J = 8.80 Hz, 1H), 7.35 (brs, 1H), 7.27 (d, J = 9.60 Hz, 1H), 7.18 (brs, 3H), 5.27 (s, 1H), 5.13 - 4.84 (m, 5H), 4.72 (brs, 1H), 4.56 (s, 1H), 4.17 (d, J = 10.40 Hz, 1H), 3.93 - 3.85 (m, 2H), 3.67 - 3.35 (m, 60H), 3.21 - 3.14 (m, 6H), 3.02 (d, J = 5.20 Hz, 15 1H), 2.59 (t, J = 8.40 Hz, 1H), 2.54 - 2.51 (m, 16H), 2.36 - 2.29 (m, 4H), 1.77 (s, 3H), 1.11 (d, J = 6.0 Hz, 3H).

[0215] EXAMPLE 15. (2R,3R,4S)-3-acetamido-2-((14S,45R,46R)-14-(4-(3-(2-((2,4- dinitrophenyl)amino)ethoxy) propanamido)butyl)-46,47-dihydroxy-13,43-dioxo-1- (((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-20 3,6,9,18,21,24,27,30,33,36,39,44-dodecaoxa-12,15,42-triazaheptatetracontan-45-yl)-4- guanidino-3,4-dihydro-2H-pyran-6-carboxylic acid (Compound 41):.

[0216] Compound 1 was prepared as described in WO 2023 / 205669 A2. - 43 -70849-04

[0217] Compound 3: To Compound 1 (0.0758 g, 0.087 mmol) and N-Boc-PEG8-bromide, (Compound 2, Broad Pharm, 0.05 g, 0.087 mmol, 1.0 eq.) in DMF (0.87 mL) were added DIPEA (0.038 µL, 0.216 mmol, 2.5 eq.) followed by potassium iodide (0.014 g, 0.087 mmol, 1.0 eq.) under argon atmosphere and stirred for 1-2 h. The reaction temperature was raised to 5 50°C using oil bath and stirred for 16 h. After reaction completion, the reaction mixture was quenched with water and extracted with EtOAc (3x 5 mL). The combined organic layers were washed with brine and dried over anhydrous Na2SO4and concentrated. The remainder was purified by column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 4 g column, 5-10% MeOH in DCM) to give 34 as a yellow solid (0.083 g, 65 %). LCMS 10 [M+H]+ = 1371.52.

[0218] Compound 4: To Compound 3 (0.083 g, 0.061 mmol) in DCM (2.0 mL) was added TFA (0.6 mL) at ice-cold temperature. Cooling was removed and stirring continued for 1h. After reaction completion, TFA was evaporated, and the remainder was washed with cold diethyl ether (3x5 mL) and hexane (2x3 mL) and dried under vacuum to give Compound 4 15 (quantitative yield), which was used without further purification. LCMS [M+H]+ = 1271.41.

[0219] Compound 6: To Compound 5 (0.046 g, 0.061 mmol) in DCM (0.6 mL) was added Compound 4 (0.077 g, 0.061 mmol, 1.0 eq.), followed by TEA (0.025 µL, 0.182 mmol, 3.0 eq.) under argon atmosphere and stirred for 2-6 h. After reaction completion, the reaction mixture diluted with water and extracted with EtOAc (3x 10 mL). The combined organic 20 layers were washed with brine, dried over anhydrous Na2SO4, and concentrated. The remainder was purified by flash column chromatography on a Teledyne CombiFlash Rf+ Lumen (silica gel, 12 g column, 5-10% MeOH in DCM) to give Compound 6 as a yellow amorphous solid (0.09 g, 79 %). LCMS [M+H]+ = 1884.14.

[0220] Compound 7: To Compound 6 (0.09 g, 0.048 mmol) dissolved in DCM (2.1 mL), 25 TFA (0.6 mL) was added at ice-cold temperature. Cooling was removed and stirring continued for 1h. After reaction completion, TFA was evaporated and the remainder was washed with cold diethyl ether (3x5 mL) and hexane (2x3 mL) to give 7 (0.079 g, quantitative yield), which was used without further purification. LCMS [M+H]+ = 1643.74.

[0221] Compound 41: Compound 7 (0.079 g, 0.048 mmol) was dissolved in MeOH (1.2 30 mL) and treated dropwise with 0.5 M sodium methoxide in MeOH (0.5 mL, 3.5 eq.) and stirred 1h. After reaction completion, the reaction mixture was neutralized by adding Dowex® 50WX8 (H+) resin, filtered, washed with MeOH and concentrated. The remainder was purified by prep-UPLC on a C18 column 5-95% gradient B over 45 min, flow 15 mL / min (A: 20 mM NH4OAc, pH 7 buffer and B: ACN; UV @ 360 nm and 240 nm) to give - 44 -70849-04 Compound 41 (3.3 mg, 50% yield). Purity 89% @360 nm and 84% @ 240 nm. LCMS [M + H]+ = 1503.62.

[0222] EXAMPLE 16. (2R,3R,4S)-3-acetamido-2-((14R,58R,59R)-14-(4-(3-(2-((2,4- dinitrophenyl)amino)ethoxy)propanamido)butyl)-59,60-dihydroxy-13,16,56-trioxo-1- 5 (((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)- 3,6,9,19,22,25,28,31,34,37,40,43,46,49,52,57-hexadecaoxa-12,15,55-triazahexacontan-58- yl)-4-guanidino-3,4-dihydro-2H-pyran-6-carboxylic acid (Compound 43):. 10

[0223] Compound 1 was prepared as described in Carbohydrate Research, 342 (2007) 1636– 1650.

[0224] Compound 3: Compound 3 was prepared using the same procedure to make Compound 10 in EXAMPLE 14. Compound 3 was made from Compound 1 (0.10 g, 0.13 mmol) in dry THF (5 ml), DIPEA (0.12 ml, 0.66 mmol), and Compound 2 (Havtech, 82.2 15 mg, 0.13 mmol) in dry THF (2 ml). After reaction completion, the mixture was concentrated and the remainder was purified by column chromatography eluting in 10% MeOH / DCM to afford Compound 3 as off white solid. Yield: 0.08 g, 48.88 %; LCMS (ESI) m / z 1230.15 [M+1]+.

[0225] Compound 5: Compound 5 was prepared using the same procedure to make 20 Compound 3 in EXAMPLE 14. Compound 5 was made from Compound 3 (0.10 g, 0.08 mmol) and Compound 4 (78.2 mg, 0.12 mmol) in DMF (3.0 mL), and HATU (0.034 g, 0.09 mmol) and ethylbis(propan-2-yl)amine (GLR, 0.08 mL, 0.41 mmol). After reaction completion, the reaction mixture was concentrated, and the remainder was purified by silica - 45 -70849-04 gel column chromatography eluting in 10% MeOH / DCM to afford Compound 5 as a yellowish liquid. Yield: 0.09 g, 53.05 %; LCMS (ESI) M / 21043.85 [M+1]+.

[0226] Compound 43 was prepared using the same procedure to make Compound 42 in EXAMPLE 14. Compound 43 was made from Compound 5 (0.09 g, 0.07 mmol) in THF (3 5 mL), MeOH (1 mL) and 1.0 M aqueous sodium hydroxide. After reaction completion, the mixture was concentrated and dried, and the remainder was purified by prep HPLC purification using water / ACN in 0.1% TFA to afford Compound 43 as a yellowish solid. Yield: 0.016 g, 21.74 %; LCMS (ESI) m / z 1706.80 [M+1]+.1H NMR (400 MHz, DMSO-d6): ^ 8.86 (d, J = 2.72 Hz, 1H), 8.82 (brs, 1H), 8.26 - 8.23 (m, 2H), 7.99 (d, J = 8.12 Hz, 1H), 10 7.94 (t, J = 5.48 Hz, 1H), 7.88 (d, J = 9.12 Hz, 1H), 7.79 (t, J = 5.24 Hz, 1H), 7.40 (d, J = 7.0 Hz, 1H), 7.27 (d, J = 9.72 Hz, 1H), 7.18 - 7.04 (m, 2H), 5.34 (brs, 1H), 4.86 - 4.79 (m, 5H), 4.55 (s, 1H), 4.22 - 4.17 (m, 3H), 3.94 - 3.83 (m, 2H), 3.66 - 3.60 (m, 6H), 3.59 - 3.56 (m, 4H), 3.53 - 3.40 ( m, 56H), 3.39 -3.32 (m, 8H), 3.23 - 3.15 (m, 4H), 3.04 - 3.01 (m, 2H), 2.97 - 2.95 (m, 2H), 2.91 - 2.76 (m, 1H), 2.61 – 2.55 (m, 5H), 2.37 (q, J = 6.52 Hz, 2H), 2.33 15 - 2.99 (m, 2H), 1.90 (s, 1H), 1.77 - 1.76 (m, 3H), 1.58 - 1.56 (m, 1H), 1.49 -1.43 (m, 1H), 1.35 - 1.29 (m, 2H), 1.28 - 1.19 (m, 3H), 1.16 - 1.11 (m, 5H), 0.99 (t, J = 7.16 Hz, 8H), 0.92 - 0.90 (m, 1H).

[0227] EXAMPLE 17. (2R,3R,4S)-3-acetamido-2-((14R,31R,32R)-14-(4-(3-(2-((2,4- dinitrophenyl)amino)ethoxy)propanamido)butyl)-32,33-dihydroxy-13,16,29-trioxo-1-20 (((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-3,6,9,30- tetraoxa-12,15,28-triazatritriacontan-31-yl)-4-guanidino-3,4-dihydro-2H-pyran-6- carboxylic acid (Compound 44):. - 46 -70849-04

[0228] Compound 1 was prepared as described in Carbohydrate Research, 342 (2007) 1636– 1650.

[0229] Compound 3: Compound 3 was prepared using the same procedure to make Compound 10 in EXAMPLE 14. Compound 10 was made from Compound 1 (0.20 g, 5 0.27 mmol) in dry THF (5 ml), DIPEA (0.25 ml, 1.33 mmol), and 12-aminododecanoic acid (Compound 2, 53.7 mg, 0.27 mmol) in dry THF (2 ml). After reaction completion, the mixture was concentrated and the remainder was purified by column chromatography eluting in 10% MeOH / DCM to afford Compound 3 as off white solid. Yield: 0.09 g, 40.86 %; LCMS (ESI) m / z 828.20 [M+1]+. 10

[0230] Compound 5: Compound 5 was prepared using the same procedure as described in EXAMPLE 14 to make Compound 1. Compound 5 was made from Compound 3 (0.09 g, 0.11 mmol) and Compound 4 (0.10 mL, 0.12 mmol) in DMF (3.0 mL) with HATU (0.045 g, 0.12 mmol) and ethylbis(propan-2-yl)amine (GLR, 0.09 mL, 0.54 mmol). After reaction completion, the reaction mixture was concentrated and the remainder was purified by silica 15 gel column chromatography eluting in 10% MeOH / DCM to afford Compound 5 as a yellowish liquid. Yield: 0.08 g, 43.68 %; LCMS (ESI) m / z 1684.30 [M+1]+.

[0231] Compound 44: Compound 44 was prepared using the same procedure to make Compound 42 from EXAMPLE 14. Compound 44 was made from Compound 5 (0.09 g, 0.05 mmol) in THF (3 mL) MeOH (1 mL), and 1.0 M aqueous NaOH. After reaction 20 completion, the mixture was concentrated and dried, and the remainder was purified by prep HPLC purification using water / ACN in 0.1% TFA to afford Compound 44 as a yellowish solid. Yield: 0.024 g, 34.44 %; LCMS (ESI) m / z 1304.9 [M+1]+.1H NMR (400 MHz, DMSO-d6): ^ 13.15 (brs, 1H), 8.86 (d, J = 2.8 Hz, 1 H), 8.82 (brs, 1H), 8.25 (dd, J = 9.28, 2.32 Hz, 1H), 7.96 (d, J = 9.0 Hz, 1H), 7.87 (t, J = 1.6 Hz, 1H), 7.78 (q, J = 8.36 Hz, 2H), 25 7.53 (d, J = 8.72 Hz, 1H), 7.26 (d, J = 9.68 Hz, 2H), 7.16 - 7.08 (m, 4H), 5.67 (s, 1H), 4.91 (d, J = 1.8 Hz, 1H), 5.15 (d, J = 1.2 Hz, 1H), 4.85 (dd, J = 3.4, 1.0 Hz, 1H), 4.71 (brs, 2H), 4.56 - 4.55 (m, 2H), 4.52 - 4.12 (m, 6H), 4.01 (q, J = 2.3 Hz, 2H), 3.85 (brs, 2H), 3.66- 3.31 (m, 26H), 3.19 - 3.17 (m, 4H), 2.90 - 2.82 (m, 5H), 2.29 (t, J = 6.36 Hz, 2H), 2.09 - 2.08 (m, 2H), 1.78 (s, 3H), 1.45 - 1.21 (m, 24H), 1.12 (d, J = 6.24 Hz, 3H). 30

[0232] EXAMPLE 18. (2R,3R,4S)-3-acetamido-2-((2R,3R)-15-((S)-2-((S)-2-((S)-2-(((R)- 23-(4-(3-(2-((2,4-dinitrophenyl)amino)ethoxy)propanamido)butyl)-21,24-dioxo-36- (((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)- 3,6,9,12,15,18,28,31,34-nonaoxa-22,25-diazahexatriacontyl)carbamoyl)pyrrolidine-1- carbonyl)pyrrolidine-1-carbonyl)pyrrolidin-1-yl)-1,2-dihydroxy-5,15-dioxo-4,9,12- - 47 -70849-04 trioxa-6-azapentadecan-3-yl)-4-guanidino-3,4-dihydro-2H-pyran-6-carboxylic acid (Compound 45):. 5

[0233] Compound 3: Compound 3 was prepared using the same procedure to make compound 3 in EXAMPLE 14. Compound 3 was made from Compound 1 (0.24 g, 0.42 mmol, Habotech) and Compound 2 (0.40 g, 0.42 mmol) in DMF (8.0 mL) with HATU (0.17 g, 0.46 mmol) and ethylbis(propan-2-yl)amine (0.22 mL, 1.25 mmol).. After reaction completion, the mixture was concentrated, and the remainder was purified by silica gel 10 column chromatography eluting in 5% MeOH / DCM to afford Compound 3 as a yellowish liquid. Yield: 0.35 g, 58.6 %; LCMS (ESI) m / z 1449.20 [M+18]+.

[0234] Compound 4: To a stirred solution of Compound 3 (0.30 g, 0.21 mmol), in anhydrous dimethyl formamide (3.0 mL), piperidine (0.6 mL) was added and the reaction mixture was stirred for 30 min. After reaction completion, the solvent was evaporated and the 15 remainder was triturated with diethyl ether to afford Compound 4 as a light yellow liquid, which was used without further purification. Yield: 0.16 g, 63.13%; LCMS (ESI) m / z 1210.20 [M+1]+.

[0235] Compound 6: Compound 6 was prepared using the same procedure to make Compound 3 from EXAMPLE 14. Compound 6 was made from Compound 4 (0.20 g, 20 0.16 mmol) and Compound 5 (0.09 g, 0.16 mmol) in DMF (5.0 mL) with HATU (0.07 g, 0.18mmol) and ethylbis(propan-2-yl)amine (0.09 mL, 0.48 mmol). After reaction completion, - 48 -70849-04 the mixture was concentrated and the remainder was purified by silica gel column chromatography eluting in 10% MeOH / DCM to afford Compound 6 as a yellowish liquid. Yield: 0.11 g, 38.61 %; LCMS (ESI) M / Z 1741.48 [M+1]+.

[0236] Compound 7: To a stirred solution of Compound 6 (0.11 g, 0.17 mmol) in 5 anhydrous dimethyl formamide (2.0 mL) piperidine (0.4 mL) was added and the reaction mixture was stirred for 30 min. After reaction completion, the solvent was evaporated, and the remainder was triturated with diethyl ether to afford Compound 7 as a light-yellow liquid, which was used without further purification. Yield: 0.085 g, 88.71%; LCMS (ESI) m / z 1500.90 [M+1]+. 10

[0237] Compound 9: Compound 9 was prepared using the same procedure to make Compound 3 in EXAMPLE 14. Compound 3 was made from Compound 7 (0.08 g, 0.05 mmol) and Compound 8 (0.04 g, 0.05 mmol) in DMF (4.0 mL) with HATU (0.02 g, 0.06 mmol) and ethylbis(propan-2-yl)amine (0.03 mL, 0.15 mmol). After reaction completion, the mixture was concentrated and the remainder was purified by silica gel column 15 chromatography eluting in 10% MeOH / DCM to afford Compound 9 as a yellowish liquid. Yield: 0.09 g, 74.86 %; LCMS (ESI) m / z 1137.60 [M / 2+1]+.

[0238] Compound 45 was prepared using the same procedure to make Compound 42 in EXAMPLE 14. Compound 45 was made from Compound 9 (0.09 g, 0.04 mmol) in THF (3 mL) and MeOH (1 mL). After reaction completion, the mixture was concentrated and dried, 20 and the remainder was purified by prep HPLC purification using water / ACN in 0.1% TFA to afford Compound 45 as a yellowish color solid. Yield: 20 mg, 26.69 %; HRMS (ESI) m / z 1892.91 [M+1]+.1H NMR (400 MHz, DMSO-d6): 8.86 (d, J = 2.80 Hz, 1H), 8.83 (brs, 1H), 8.26 (dd, J = 9.2 & 2.4 Hz, 1H), 8.00 - 7.90 (m, 3H), 7.83 - 7.78 (m, 2H), 7.53 (brs, 1H), 7.27 (d, J = 9.6 Hz, 2H), 7.22 - 7.20 (m, 1H), 5.66 (brs, 1H), 5.09 (brs, 1H), 4.84 (dd, J = 10.8 & 25 2.0 Hz, 1H), 4.76 - 4.73 (m, 2H), 4.61 - 4.51 (m, 4H), 4.36 -4.28 (m, 1H), 4.26 - 4.19 (m, 3H), 3.99 (qt, J = 8.8 Hz, 1H), 3.81 (brs, 1H), 3.65 - 3.58 (m, 10H), 3.53 - 3.24 (m, 64H), 2.49 - 2.33 (m, 4H), 2.25 - 2.1.83 (m, 7H), 1.80 (s, 3H), 1.62 - 1.1.55 (m, 1H), 1.45 - 1.30 (m, 3H), 1.25 - 1.18 (m, 1H), 1.11 (d, J = 6.4 Hz, 3H).

[0239] EXAMPLE 19. (2R,3R,4S)-3-acetamido-2-((14R,17R,23R,29R,58R,59R)-14-(4-(3-30 (2-((2,4-dinitrophenyl)amino)ethoxy)propanamido)butyl)-59,60-dihydroxy-17,23,29- tris(hydroxymethyl)-13,16,19,22,25,28,31,34,56-nonaoxo-1-(((2R,3R,4R,5R,6S)-3,4,5- trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-3,6,9,37,40,43,46,49,52,57-decaoxa- 12,15,18,21,24,27,30,33,55-nonaazahexacontan-58-yl)-4-guanidino-3,4-dihydro-2H- pyran-6-carboxylic acid (Compound 46): - 49 -70849-04.

[0240] Compound 8a: Solid phase peptide synthesis (SPS) of Compound 8 was performed manually in a peptide reaction vessel using 2-CTC resin under standard peptide coupling and 5 deprotection protocol using Fmoc and tBu protection groups.

[0241] General Procedure for Amide coupling: To the reaction vessel containing swollen 2CTC resin is added activated amino acid solution, prepared by weighing out an appropriate amount of Fmoc-Gly-OH (Chemscene, 2.0 eq) or Fmoc-Ser(OtBu)-OH (BLD pharma, 2.0 eq.) or 1-(9H-fluoren-9-yl)-3-oxo-2,7,10,13,16,19,22-heptaoxa-4-azapentacosan-25-oic acid 10 (Habotech; 2.0 eq) in DMF, and HATU (2.5 eq.) and DIPEA (3.0 eq.). The reaction vessel is shaken for 2 h.

[0242] General Procedure for Fmoc De-protection: Reaction vessel containing resins in 20% piperidine in DMF is shaken at for 0.5 h to de-protect Fmoc groups. - 50 -70849-04

[0243] Compound 8: To the reaction vessel containing swollen 2CTC resin loaded Compound 6 was added a solution of Compound 7 (2.0 eq.) in dry THF followed by DIPEA (GLR, 3 eq.) dropwise. The reaction vessel was shaken for 24 h.

[0244] Compound 8a (Resin Cleavage): 2CTC resin loaded with Compound 8 was 5 suspended in 20% 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) in DCM in a peptide reaction vessel. The reaction vessel was shaken for 30 min. The resin was filtered and washed three times with 10 mL portions of 20% HFIP in DCM. To the combined filtrates was added chilled diethyl ether to give Compound 8a as a white solid. Yield: 250 mg. LC-MS (ESI) m / z 1567.45 [M+1]+. 10

[0245] Compound 10: Compound 10 was prepared using the same procedure to make Compound 3 in EXAMPLE 14. Compound 10 was made from Compound 8 (0.25 g, 0.10 mmol) and Compound 9 (0.11 g, 0.11 mmol) in DMF (6.0 mL) with HATU (Chempure, 0.043 g, 0.33 mmol) and ethylbis(propan-2-yl)amine (GLR, 0.08 mL, 0.11 mmol). After reaction completion, the mixture was concentrated and the remainder was purified by silica 15 gel column chromatography eluting in 5% MeOH / DCM to afford Compound 10 as a yellowish liquid. Yield: 0.16 g, 63.65 %; LCMS m / z 1211.85 [M / 2+1]+.

[0246] Compound 46: Compound 46 was prepared using the same procedure to make Compound 42 in EXAMPLE 14. Compound 46 was made from Compound 10 (0.12 g, 0.05 mmol) in THF (3 mL) and MeOH (1 mL). After reaction completion, the mixture was 20 concentrated and dried, and the remainder was purified by prep HPLC purification using water / ACN in 0.1% TFA to afford Compound 46 as a yellowish solid. Yield: 0.019 g, 20.47 %; HRMS (ESI) m / z 1874.82 [M+1]+.1H NMR (400 MHz, DMSO-d6): 8.86 (d, J = 2.80 Hz, 1H), 8.83 (brs, 1H), 8.27 - 8.24 (m, 3H), 8.14 (brs, 1H), 8.02 - 7.92 (m, 4H), 7.84 - 7.79 (m, 2H), 7.51 (brs, 1H), 7.27 (d, J = 10.6 Hz, 2H), 7.07 - 7.01 (m, 3H), 5.60 (brs, 1H), 5.16 - 5.06 25 ( m, 3H), 4.83 (d, J = 10.6 Hz, 1H), 4.74 - 4.73 (m, 2H), 4.56 (s, 2H), 4.48 (brs, 1H), 4.33 - 4.20 (m, 5H), 4.15 - 4.14 (m, 1H), 3.96 (qt, J = 9.2 Hz, 1H), 3.84 - 3.72 (m, 7H), 3.66 - 3.55 (m, 15H), 3.54 - 3.45 (m, 30 H), 3.44 - 3.36 (m, 7H), 3.23 - 3.16 (m, 4H), 3.05 - 2.5 (4H), 2.38 (t, J = 8.4 Hz, 1H), 2.30 (t, J = 8.4 Hz, 1H), 1.78 (s, 3H), 1.70 - 1.60 (m, 1H), 1.55 - 1.45 (m, 1H), 1.38 - 1.23 (m, 4H), 1.12 (d, J = 6.4 Hz, 3H). 30 - 51 -70849-04

[0248] EXAMPLE 20. Ethyl (3R,4R,5S)-4-acetamido-5-(3-(25-(18-((2,4- dinitrophenyl)amino)-13-oxo-3,6,9,16-tetraoxa-12-azaoctadecyl)-13,26-dioxo-1- (((2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)- 3,6,9,16,19,22,29,32-octaoxa-12,25-diazatetratriacontan-34-yl)ureido)-3-(pentan-3- 5.

[0249] Compound 3: Compound 3 was prepared as described in Eur. J. Med. Chem., 2020, 200, 112423 using commercially available Oseltamivir (Compound 1, BLD) and Amino- 10 Peg2-t-butyl ester (Compound 2, BLD).

[0250] Compound 4: To a stirred solution of Compound 3 (0.10 g, 0.17 mmol) in anhydrous DCM (3.0 mL), TFA (1.0 mL) was added at 0 °C. Cooling was discontinued, and the reaction mixture was stirred for 12 h. After reaction completion, the solvent was evaporated to Compound 4 as a light yellow liquid which was used for the next reaction. 15 Yield: 0.08 g; LCMS (ESI) m / z 516.20 [M+1]+.

[0251] Compound 6: Compound 6 was prepared using the same procedure to make Compound 3 in EXAMPLE 14. Compound 6 was made from Compound 4 (0.15 g, 0.29 mmol) and Compound 5 (0.36 g, 0.32 mmol) in DMF (8.0 mL) with HATU (0.17 g, 0.32 mmol) and ethylbis(propan-2-yl)amine (GLR, 0.27 mL, 1.45 mmol). After reaction - 52 -70849-04 completion, the mixture was concentrated, and the remainder was purified by silica gel column chromatography eluting in 10% MeOH / DCM to afford Compound 6 as a yellowish liquid. Yield: 0.095 g, 22.05 %; LCMS (ESI) m / z 1622.65 [M+1]+.

[0252] Compound 47: To a stirred solution of Compound 6 (0.10 g, 0.061 mmol) in ethanol 5 (5.0 mL) was added sodium ethoxide (0.41 mg, 0.002 mmol) at 0 °C. Cooling was discontinued, and the reaction mixture was stirred for 1 h. After reaction completion, the reaction mixture was treated with acidic (Dowex 50, H+) to pH~7 and the suspension was filtered through a sintered funnel with MeOH wash. The filtrate was concentrated, and the remainder was purified by prep HPLC to afford Compound 47 as a yellowish color solid. 10 Yield: 25 mg, 27.11 %; LCMS (ESI) m / z 1496.80 [M+1]+.1H NMR (400 MHz, DMSO-d6): ^ 8.86 (d, J = 2.80 Hz, 1H), 8.83 (brs, 1H), 8.25 (dd, J = 9.2 & 2.4 Hz, 1H), 7.90 (m, 2H), 7.80 (d, J = 8.8 Hz, 1H), 7.27 (d, J = 9.6 Hz, 1H), 6.10 (brs, 1H), 5.77 (d, J = 7.2 Hz, 1H), 4.55 (d, J = 1.6 Hz, 1H), 4.16 - 4.10 (m, 2H), 4.08 - 4.03 (m, 1H), 3.76 - 3.55 (m, 22H), 3.53 - 3.33 (m, 51H), 3.20 - 3.13 (m, 8H), 2.61 - 2.57 (m, 4H), 2.34 - 2.29 (m, 5H), 1.78 (s, 3H), 15 1.47 - 1.32 (m, 4H), 1.21 (d, J = 7.2 Hz, 3H), 1.11 (d, J = 6.0 Hz, 3H), 0.83 (t, J = 7.2 Hz, 3H), 0.76 (t, J = 7.2 Hz, 3H). DRUG PRODUCT EXAMPLES

[0253] DRUG PRODUCT EXAMPLE 1. Drug Product 1: Compound 24 drug product is an intermediate bulk solution configured for nasal (IN) administration, presented in dosage 20 strengths ranging from 2.5 mg / mL to 250 mg / mL. In addition to the active ingredient Compound 24, the clinical formulation contains the following excipients: Up to 6 mg / mL n- dodecyl-beta-D-maltoside (DDM) and 1x Phosphate-Buffered Saline (PBS). The intranasal formulation may be administered using conventional devices, such as but not limited to the Aptar Unidose nasal device.25Compound 24- 53 -70849-04- 54 -70849-04

[0254] A series of generally recognized as safe (GRAS) nasal excipients were investigated, including, but not limited to, thickeners, mucoadhesives, solubilizing agents, permeability agents, and the like. Without being bound by theory, it is believed herein that the solubility and / or the permeability of Compound 24 in phosphate-buffered saline (PBS) (100 mg / mL) 5 limits the administrable dose, and therefore solubility and permeability agents were investigated to raise the feasible concentration to a higher level and improve uptake.

[0255] It has been discovered that n-dodecyl ^-D-maltoside (DDM) improves the solubility of Compound 24 from 100 mg / mL to 500 mg / mL in a conventional carrier, PBS, and improves membrane permeability, and increases the intranasal bioavailability of Compound 10 24. DDM allows Compound 24 to be dosed at clinically relevant levels.

[0256] DRUG PRODUCT EXAMPLE 2. Drug Product 2: Compound 24 drug product is an intermediate bulk solution configured for nasal (IN) administration, presented in dosage strengths ranging from 2.5 mg / mL to 250 mg / mL. In addition to the active ingredient, Compound 24, the clinical formulation contains the following excipients: up to 6 mg / mL n- 15 dodecyl-beta-D-maltoside (DDM), up to 2% (weight / volume) Avicel® RC 591, and 1x PBS. The intranasal formulation may be administered using conventional devices, such as but not limited to the Aptar Unidose nasal device. In some embodiments, the intranasal (IN) formulations may be thickened, where such formulations comprise lower levels of the compounds described herein, such as Compound 24. Thickening agents, such as MCC 20 and / or CMC, may be added. An illustrative formulation includes by volume, 2% Avicel® RC 591 (microcrystalline cellulose / carboxymethyl cellulose), 0.6% DDM, and 1X PBS in deionized ultra-filtered (DIUF) Water.

[0257] An illustrative intranasal formulation comprising DDM and Avicel® RC 591 is prepared as follows: 25 1. Avicel® RC 591 Stock Solution. Add a target weight of the Avicel® RC 591 slowly to the desired volume of DIUF water. Allow the preparation to stir for at least 24 hours at room temperature. For a 40 mg / mL Example formulation: 4 g of Avicel® RC 591 to 100 mL of DIUF water. 2. DDM Stock Solution. Add a target weight of the DDM slowly to the desired volume of 30 DIUF water. Sonicate and stir until dissolved. Store refrigerated. For a 60 mg / mL Example formulation: 6 g of DDM to 100 mL DIUF water. 3. DDM in PBS vehicle. Measure ~25 mL of DIUF water into a calibrated beaker of 100 mL, add a stir bar and place on stir plate. Measure 50 mL of the Avicel solution and add it to the beaker while stirring at a moderate speed. Measure 10 mL of the DDM Solution - 55 -70849-04 and add it to the beaker while stirring at a moderate speed. Measure 10 mL of the 10x PBS solution and add it to the beaker while stirring at a moderate speed. Bring to final volume of 100 mL with DIUF water and continue stirring until, homogenous formulation is achieved. 5

[0258] Compound 24 is weighed into a calibrated glass container and diluted to an appropriate volume of 6 mg / mL DDM, 1x PBS, in 20 mg / mL Avicel® RC 591. For a 500 mg / mL formulation: 1. Weigh 5.450g of EV-25 and slowly add to 1 mL of 60 mg / mL DDM / DIUF stock solution in a container calibrated to a 10 mL volume. This will be done in increments 10 with sonication. Formulation will be chunky and thick and will take several hours of sonication. The end product will be honey thick and may still contain a few chunks. 2. Add 1 mL of 10x PBS. Continue to sonicate and vortex as needed to dissolve. 3. Once dissolved, add 5 mL volume with 40 mg / mL Avicel stock solution. Finally, bring the formulation to a 10 mL volume with DIUF. 15 4. Vigorously vortex and sonicate for several hours or overnight.

[0259] An illustrative intranasal formulation comprising DDM and Avicel® RC 591 is prepared as follows: 1. A stock solution of 60 mg / mL DDM is prepared in de-ionized water. 2. A stock solution of 40 mg / mL Avicel® RC 591 is prepared in de-ionized water, 20 sonicated for 1 hour, and allowed to thicken for no less than 24 hours before use. 3. Desired quantity of Compound 24 is weighed and placed in a plastic tube. 4.10% of the final formulation volume is added from the 60mg / mL stock solution of DDM 5.10% of the final formulation volume is added from a 10x PBS solution. 25 6.30% of the final formulation volume is added from de-ionized water. 7. The formulation is sonicated for up to an hour to ensure complete dissolution of Compound 24. 8.50% of the final volume is added from a stock solution of 40 mg / mL Avicel® RC 591 prepared in de-ionized water. 30 9. Final concentrations: 1X PBS, 6 mg / mL DDM, 20 mg / mL Avicel® RC 591.

[0260] DRUG PRODUCT EXAMPLE 3. Drug Product 3: Compound 24 drug product is an intermediate bulk solution configured for subcutaneous (SC) administration. An illustrative formulation includes 1X PBS in deionized ultra-filtered (DIUF) water. The formulation is prepared by dissolving the appropriate amount of Compound 24 in a - 56 -70849-04 measured volume of PBS vehicle to obtain the predetermined concentrations. Formulations are filtered using a 0.2 µm PES (polyethersulfone) syringe filter, for SC administration.

[0261] Formulations prepared before the day of administration or on the day of administration are held at room temperature (15 °C to 30 °C) prior to dose administration. 5 Formulations prepared before the day of administration are stored refrigerated (2 °C to 8 °C) until the day of administration. Formulations are allowed to acclimate to room temperature for at least 30 minutes prior to administration.

[0262] DRUG PRODUCT EXAMPLE 4. Drug Product 4: Compound 24 drug product is an intermediate bulk solution configured for intravenous (IV) administration. An illustrative 10 formulation includes 1X PBS in deionized ultra-filtered (DIUF) water. The formulation is prepared by dissolving the appropriate amount of Compound 24 in a measured volume of PBS vehicle to obtain the predetermined concentrations. Formulations are filtered using a 0.2 µm PES (polyethersulfone) syringe filter, for SC administration.

[0263] Formulations prepared before the day of administration or on the day of 15 administration are held at room temperature (15 °C to 30 °C) prior to dose administration. Formulations prepared before the day of administration are stored refrigerated (2 °C to 8 °C) until the day of administration. Formulations are allowed to acclimate to room temperature for at least 30 minutes prior to administration. METHOD EXAMPLES 20

[0264] METHOD EXAMPLE 1. Binding affinity to HEK expressing neuraminidase: The Kiof Compound 24 when competed against zanamivir-rhodamine (Nature Communications 11, Article number: 5597 (2020)) was determined using a binding and competition assay. First, the Kd of zanamivir-rhodamine binding to neuraminidase is determined. Human Embryonic Kidney cells (HEK239) transfected with influenza viral neuraminidase are 25 suspended in staining buffer (2% fetal bovine serum in phosphate buffered saline) at a density of 2 million cells / mL, and then plated in triplicate (50 µL / well) in a u-bottom plate. Next, two sets of serial dilutions of zanamivir-rhodamine are made in staining buffer. In one set, 100x concentration of zanamivir is included to determine non-specific binding. The diluted compounds are added to the cells (50 µl / well) and incubated on a shaker at room temperature 30 for 1 h. Cells are washed twice with 200 µL of phosphate-buffered saline and resuspended in 150 µL of staining buffer. Fluorescence is measured using an Attune NxT flow cytometer (Fisher), and Kdis calculated using Graph Pad Prism, One site – total and non-specific binding. - 57 -70849-04

[0265] Next the Ki of Compound 24 and zanamivir can be determined. Cells are plated as described above. One set of serial dilutions is made for Compound 24 and a separate set is made for zanamivir. Each dilution is mixed with an equal volume of 80 nM zanamivir- rhodamine. The compound mixture is added to the cells (50 µL / well) and incubated on a 5 shaker at room temperature for 1 h. Cells are washed and resuspended as described above. Fluorescence is measured using an Attune NxT flow cytometer (fisher). Using the Kdcalculated above and a final concentration of 20 nM zanamivir-rhodamine, the Kican be calculated using Graph Pad Prism, One site – Fit Ki.

[0266] FIG.8 shows that zanamivir-rhodamine binds to neuraminidase with a binding 10 affinity of 8.253 nM. It is well established in the literature that zanamivir binds to neuraminidase, and excess zanamivir blocking fluorescence shows that zanamivir-rhodamine is binding to neuraminidase. This same rhodamine conjugate is used to quantify inhibitor constants for Compound 24 and zanamivir (FIG.9). Zanamivir has a Ki of 0.496 nM. The Ki of Compound 24 is in the low nanomolar range at 7.152 nM. 15

[0267] METHOD EXAMPLE 2. Dose range finding study – Viral Titers: A group of 6-8 weeks old female BALB / c mice (n = 5 / group) were infected with 10 LD50 of Influenza virus H3N2 / Wisconsin / 15 / 2009 on day 0 of the experiment. Mice were given an intraperitoneal injection of 6 g / kg human IVIg at 24 hpi to achieve humanized titer of anti-DNP and anti- Rhamnose antibodies at the time of test article administration. Mice were treated with test 20 articles at 48 hpi. Compound 24 was administered as a single intranasal dose of 2.2 mg / kg, 0.72 mg / kg, 0.24 mg / kg or, 0.081 mg / kg in the designated cohorts. Mice in the two control groups received Tamiflu® (oseltamivir phosphate) as a positive control (5 mg / kg b.i.d. for 5 days) and Vehicle (PBS) as placebo. Viral titers in mouse lungs were measured in 2 ways: live, infectious virus is measured using a hemagglutination assay, and total viral RNA is25 measured using reverse transcription polymerase chain reaction (rt-PCR). However, the rt- PCR method cannot distinguish between live and dead viruses so is not valuable in determining efficacy.

[0268] First the mouse lungs are homogenized in 5 µL of cold phosphate buffered saline per milligram of tissue. 100 µL of lysate is saved for RNA isolation, and the remaining lysate is 30 used for hemagglutination. All samples are stored at -80 .

[0269] For the hemagglutination assay, MDCK-London (Madin-Darby canine kidney) cells are plated in a 96-well plate and incubated till confluent. On the day of the assay, lung lysate is serially diluted 3-fold in DMEM / F12 (1:1) supplemented with 0.3% bovine serum albumin. MDCK-London cells are washed and 50 µL of diluted lysate is added to each well, so that - 58 -70849-04 each dilution has 4 replicates. Cells are incubated for 1 hour at 37 °C, 5% CO2, and then 200 µL of DMEM / F12 (1:1) supplemented with 0.3% bovine serum albumin and 1 µg / ml of trypsin are added to each well. Cells are incubated 48 hours at 37 °C and 5% CO2. Each well is tested for hemagglutination by incubating 50 µL of tissue culture supernatant with 50 µL 5 of 0.5% turkey red blood cells in phosphate buffered saline in a v-bottom plate. After 30 min at room temperature, the plate is tilted 45-degrees and wells are counted as negative or positive. Negative wells have a red dot, which runs when the plate is tilted, resembling the negative control. Positive wells will appear hazy and will not have a red dot at the bottom of the well. TCID50 is calculated for each lung sample using the Reed-Muench method, and 10 values are plotted using Graph pad prism.

[0270] FIG.4 shows that much of the live, infectious virus is cleared after treatment with Compound 24. This is supported by the high survival rates and quick weight recovery of mice treated with Compound 24 as seen in Method Example 5 and the corresponding figures. 15

[0271] METHOD EXAMPLE 3. Neuraminidase inhibition assay: To evaluate the neuraminidase inhibition activity of Compound 24, a standard neuraminidase inhibition assay was performed using the NA-FluorTMInfluenza Neuraminidase Assay Kit (Catalog no. 4457091, InvitrogenTM). The assay was performed according to the manufacturer’s protocol. In brief, a standard curve was generated first using the 4-methylumbelliferone sodium salt (4- 20 MU(SS)) to determine the linear range of substrate turnover detection on the Synergy Neo2 HTS Multi-Mode Microplate Reader (Biotek). A Relative Fluorescence Unit (RFU) value was identified within the linear range of fluorescence detection on the instrument. For each viral strain, the dilution factor to be used in the assay was decided that best corresponds to the chosen Relative Fluorescence Unit (RFU) value from the 4-methylumbelliferone sodium salt 25 (4-MU(SS)) standard curve. Then the virus stock solutions were titrated by a neuraminidase activity assay. For this assay, serial dilutions of the virus stock solutions were prepared in a black, 96-well, flat bottom plate. Then 50 µL of 200 µM of the NA-FluorTMsubstrate (MUNANA, 4-(methylumbelliferyl)-N-acetylneuraminic acid) was added to the designated wells. The plate was incubated at 37°C for 60 min, protected from light. The plate was placed30 on a shaker inside the incubator. Then the reaction was terminated by adding 100 µL of NA- fluorTMstop solution (0.2 M sodium carbonate) to each well. Then the fluorescence intensities were measured using an excitation wavelength of 350 nm and emission wavelength of 440 nm. The Relative Fluorescence Unit (RFU) values were plotted against the respective virus dilutions and for each virus strain, the dilution factor that yields the RFU - 59 -70849-04 chosen from the 4-methylumbelliferone sodium salt (4-MU(SS)) standard curve was selected to use for neuraminidase activity normalization in the neuraminidase inhibition assay. Finally, for the neuraminidase inhibition assay, serial tenfold dilutions of the test compounds were prepared in NA-FluorTMassay buffer (66.6 mM 2-(N-morpholino)ethanesulfonic acid 5 (MES) buffer, 8 mM CaCl2, pH 6.5). Then 25 µL of the 4X Compound 24 dilution series was added to all rows of a 96-well plate followed by addition of 25 µL of 1X assay buffer to the no virus control wells.25 µL of diluted virus samples were added to the designated wells and mixed with the Compound 24 dilutions. The plate was incubated for 30 min at 37°C with shaking. Then 50 µL of the diluted 200 µM NA-FluorTMsubstrate was added to each 10 well and incubated for 60 min at 37°C protected from light. The reaction was terminated by adding 100 µL of NA-FluorTMstop solution to all wells. The plate was read for measuring fluorescence intensities using an excitation wavelength of 350 nm and emission wavelength of 440 nm. The data was plotted using GraphPad Prism 10.0.0 software to generate the sigmoid dose-response curve. Then the graph was analyzed using a built-in nonlinear 15 regression curve-fitting program to determine the half-maximal inhibitory concentration (IC50). Lower IC50 values indicate higher potency of the compound.

[0272] FIG.11 demonstrates the sigmoidal dose-response curves for each viral strain and the table therein denotes their respective half-maximal inhibitory concentration (IC50) values. These data illustrate that the zanamivir targeting ligand moiety in Compound 24 is not only 20 able to engage the target enzyme but also inhibit its function and act as a direct acting antiviral across many strains. Neuraminidase inhibition suppresses the budding of virus particles from infected cells and limits the spread of the infection to neighboring healthy cells.

[0273] Table 5 shows the half-maximal inhibitory concentration (IC50) values for 25 Compound 24 against multiple influenza strains. Table 5. IC50 values for Compound 24 against seasonal and multiple influenza strains

[0274] METHOD EXAMPLE 4. A group of 6-8 weeks old female BALB / c mice (n = 5 / group) were infected with 10 LD50 of influenza virus A / H1N1 / PR8 / 1934 on day 0 of the - 60 -70849-04 experiment. Mice were given an intraperitoneal injection of 6 g / kg human IVIg 24 hours before drug administration to achieve humanized titer of anti-DNP and anti-Rhamnose antibodies at the time of test article administration. Mice were treated with test articles at 48 hpi (FIG. 1) or, 96 hpi (FIG.2). Compound 24 (no DDM or Avicel® RC 591was 5 administered as a single intranasal dose of 1.5 µmol / kg, or single intravenous dose of 1.5 µmol / kg, or single oral dose of 13.5 µmol / kg in the designated cohorts. Mice in the three control groups received Tamiflu® (oseltamivir phosphate), or Xofluza® (baloxavir marboxil) or, PBS as placebo.

[0275] For evaluation of drug efficacy, mice were weighed and monitored daily for 14 days 10 post-infection and counted as dead when they lost 25% of their body weight or were diagnosed as moribund.

[0276] Results of this experiment are depicted body weight plots, which graph days after infection vs. survival (%) and days after infection vs. body weight (%) for mice (n = 5 / group). 15

[0277] At the early-stage treatment (48hpi) mice treated with 1.5 µmol / kg single intranasal dose of Compound 24 resulted in 100% survival, 1.5 µmol / kg single intravenous dose of Compound 24 resulted in 100% survival and the cohort treated with single oral dose resulted in 80% survival. Mice treated with Tamiflu® with 5 mg / kg dosage, dosed twice daily for five days resulted in 60% survival and mice treated with Xofluza® with 10 mg / kg single oral dose 20 resulted in 80% survival. On the other hand, At the late-stage treatment (96 hpi) mice treated with 1.5 µmol / kg single intranasal dose of Compound 24 resulted in 100% survival, 1.5 µmol / kg single intravenous dose of Compound 24 resulted in 80% survival and the cohort treated with single oral dose resulted in 60% survival. Mice treated with Tamiflu® with 5 mg / kg dosage, dosed twice daily for five days resulted in 20% survival and mice treated with 25 Xofluza® with 10 mg / kg single oral dose resulted in 60% survival.

[0278] It indicates the superior efficacy of Compound 24 over Tamiflu® and Xofluza® at both early and late stages of infection and demonstrates that all the three routes of administration are effective with intranasal being the best route of administration at 1.5 µmol / kg dose. 30

[0279] METHOD EXAMPLE 5. Dose range finding study – Efficacy / Toxicity: In the study of Method Example 2, survival, and cytokine response were also measured. With respect to weight gain, mice were weighed and monitored daily for 14 days post-infection and counted as dead when they lost 25% of their body weight or were diagnosed as - 61 -70849-04 moribund.

[0280] Results of this experiment are depicted in FIG. 3. FIG. 3 is a graph of days after infection vs. survival (%) and days after infection vs. body weight (%) for mice (n = 5 / group) infected with 10 LD50 of influenza A H3N2 / Wisconsin / 15 / 2009, intraperitoneal 5 administration of human IgG (IVIg (GAMUNEX®-C) at 24 hpi, and administration of conjugate at 48 hpi.

[0281] Mice treated with 2.2 mg / kg, 0.72 mg / kg and 0.24 mg / kg single intranasal dose of Compound 24 (no DDM or Avicel® RC 591) resulted in 100% survival and the cohort treated with 0.081 mg / kg single intranasal dose resulted in 60% survival. Mice treated with 10 Tamiflu® with 5 mg / kg dosage, dosed twice daily for five days also resulted in 60% survival. It indicates the superior efficacy of Compound 24 over Tamiflu® and demonstrates that 0.24 mg / kg dosage can be considered as the minimal effective dose of Compound 24 to achieve a 100% survival in mice. Mice in all cohorts had a gradual loss in body weight but the ones that survived could recover the weight loss induced by viral infection. These data show that 15 Compound 24 is 100% effective and even at 9-fold lower dose, a single dose of Compound 24 is comparable to Tamiflu® dosed 10 times in a period of five days.

[0282] The cytokines from each of the treatment and control groups were measured in lung tissue samples (n=3 / group) via BioLegend’s LEGENDplex™ bead-based immunoassay using standard protocol provided by the manufacturer (BioLegend, San Diego, CA). 20

[0283] FIGS. 12 (lungs) and 13 (serum) show graphs of specific cytokine expression levels in the lungs and serum respectively, measured for each group at 24 h after drug administration Compound 24, administered intranasally, did not induce a cytokine storm in the lungs or serum. A dose-dependent decrease in IFN-! was observed in the lungs. The level of TNF- ^ and 12 other inflammatory cytokines not reported here but included in 25 BioLegend’s LEGENDplex kit was unaltered in both lungs and serum. With respect to IL-6, the data shown were not statistically significant. By comparison, the drop in IFN- ! in lungs is indicative of a reduction in systemic inflammation due to faster clearance of the infection upon treatment with Compound 24. In serum, the IFN- ! showed an increase, but with large error bars which are not statistically significant. These data indicate that Compound 24 does 30 not induce a cytokine storm.

[0284] METHOD EXAMPLE 6. A cytokine release assay was performed on Compound 24 (results in FIG. 10) to assess the risk of causing a cytokine storm in humans. For this assay, human PBMCs pooled from at least 4 donors were washed and plated at 5x105cells / well. 1000 nM of Compound 24 was added to the PBMCs with and without 10 mg / mL IVIG to - 62 -70849-04 reach a final volume of 200 µL.1000 nM of a TLR7 agonist was used as a positive control, and media was used as a negative control. The PBMCs were incubated with compound at 37 °C, 5% CO2, and samples of supernatant were collected at 2, 6, and 24 h. Supernatant was centrifuged at 450xg for 10 min to remove cells, and stored at -80 °C. 5

[0285] Cytokines in the supernatant were measured using a Human Anti-Virus Response Panel (biolegend). This kit measures 13 different proteins: IL-1^, IL-6, IL-8, IL-10, IL- 12p70, IFN-^2, IFN-^, IFN-"1, IFN-"2 / 3, IFN-!, TNF-^, IP-10, GM-CSF, using fluorescently coded beads and fluorescently labeled antibodies. Fluorescence was measured using an Attune NxT flow cytometer (Fisher), and the concentration of each protein is 10 quantified using LEGENDplex™ software (biolegend). Finally, data was graphed with GraphPad prism.

[0286] In all the cytokines tested, Compound 24 had similar levels to the negative control, indicating no inherent immunogenicity from the molecule by itself. Because Compound 24 could potentially bind 2 antibodies, IVIG was included to determine the risk of forming an 15 aggregate, which would trigger an immune response. IVIG was at a physiologically relevant concentration of 10 mg / mL, which caused a higher background in some of the proteins tested. Considering this, Compound 24 again had similar levels to the negative control, indicating no immunogenicity from the molecule when bound to antibodies. This suggests that Compound 24 would not recruit immune cells in circulation and is unlikely to induce 20 cytokine release if not bound to neuraminidase expressing cells or virus.

[0287] METHOD EXAMPLE 7. To evaluate the neuraminidase inhibition activity of Compound 41, a standard neuraminidase inhibition assay was performed using the NA- FluorTMInfluenza Neuraminidase Assay Kit (Catalog no. 4457091, InvitrogenTM). The assay was performed according to the manufacturer’s protocol. In brief, a standard curve was 25 generated first using the 4-methylumbelliferone sodium salt (4-MU(SS)) to determine the linear range of substrate turnover detection on the Synergy Neo2 HTS Multi-Mode Microplate Reader (Biotek). A Relative Fluorescence Unit (RFU) value was identified within the linear range of fluorescence detection on the instrument. For each viral strain, the dilution factor to be used in the assay was decided that best corresponds to the chosen Relative 30 Fluorescence Unit (RFU) value from the 4-methylumbelliferone sodium salt (4-MU(SS)) standard curve. Then the virus stock solutions were titrated by a neuraminidase activity assay. For this assay, serial dilutions of the virus stock solutions were prepared in a black, 96-well, flat bottom plate. Then 50 µL of 200 µM of the NA-FluorTMsubstrate (MUNANA, 4- (methylumbelliferyl)-N-acetylneuraminic acid) was added to the designated wells. The plate - 63 -70849-04 was incubated at 37°C for 60 min, protected from light. The plate was placed on a shaker inside the incubator. Then the reaction was terminated by adding 100 µL of NA-FluorTMstop solution (0.2 M sodium carbonate) to each well. Then the fluorescence intensities were measured using an excitation wavelength of 350 nm and emission wavelength of 440 nm. 5 The Relative Fluorescence Unit (RFU) values were plotted against the respective virus dilutions and for each virus strain, the dilution factor that yields the RFU chosen from the 4- methylumbelliferone sodium salt (4-MU(SS)) standard curve was selected to use for neuraminidase activity normalization in the neuraminidase inhibition assay. Finally, for the neuraminidase inhibition assay, serial tenfold dilutions of the test compounds were prepared 10 in NA-FluorTMassay buffer (66.6 mM 2-(N-morpholino)ethanesulfonic acid (MES) buffer, 8 mM CaCl2, pH 6.5). Then 25 µL of the 4X Compound 41 dilution series was added to all rows of a 96-well plate followed by addition of 25 µL of 1X assay buffer to the no virus control wells. 25 µL of diluted virus samples were added to the designated wells and mixed with the Compound 41 dilutions. The plate was incubated for 30 min at 37°C with shaking. 15 Then 50 µL of the diluted 200 µM NA-FluorTMsubstrate was added to each well and incubated for 60 min at 37°C protected from light. The reaction was terminated by adding 100 µL of NA-FluorTMstop solution to all wells. The plate was read for measuring fluorescence intensities using an excitation wavelength of 350 nm and emission wavelength of 440nm. The data was plotted using GraphPad Prism 10.0.0 software to generate the 20 sigmoid dose-response curve. Then the graph was analyzed using a built-in nonlinear regression curve-fitting program to determine the half-maximal inhibitory concentration (IC50). Lower IC50 values indicate higher potency of the compound.

[0288] FIG.12 demonstrates the sigmoidal dose-response curves for each viral strain and the table therein denotes their respective half-maximal inhibitory concentration (IC50) values 25 related to Compound 41. This data illustrates that the zanamivir targeting ligand moiety in Compound 41 is not only able to engage the target enzyme but also inhibit its function and act as a direct-acting antiviral agent across many strains. Neuraminidase inhibition suppresses the budding of virus particles from infected cells and limits the spread of the infection to neighboring healthy cells. 30

[0289] METHOD EXAMPLE 8. Efficacy of Compound 24 intranasal (IN) formulation against Multiple Influenza Strains (FIG.14A and FIG.14B): Efficacy of an intranasal formulation of Compound 24 (0.6% n-dodecyl ^-D-maltoside, “DDM” and 2% Avicel 591 in PBS), referred to as “Compound 24 IN”) was evaluated in 3 seasonal Influenza strains: A / H3N2 / Wisconsin / 15 / 2009, A / California / 07 / 2009(H1N1) pdm09, a pandemic strain of - 64 -70849-04 H1N1 that represents a large portion of the seasonal flu burden every year, and B / Brisbane / 60 / 2008). In FIG.14A and FIG.14B, Compound 24 Intranasal (IN) was compared with oseltamivir phosphate (oral) and vehicle control (0.6% DDM and 2% Avicel 591 in PBS and intranasal). In each study, mice were infected with 10x LD50 of 1 of 3 5 seasonal influenza strains and given either 2.2 mg / kg Compound 24 IN, oseltamivir phosphate orally, or a vehicle control at 48 h post-infection intranasally. Sub-cohorts were sacrificed 24 h post-infection to detect viral titers in the lungs. The rest of the group was observed for the following 14 days as part of a survival study with body weight recorded daily. 10

[0290] As shown in FIG.14A, Compound 24 IN against A / H3N2 / Wisconsin / 15 / 2009 showed 100% survival in contrast to the group that received oseltamivir phosphate (60% survival) and the vehicle control (0% survival). A Mantel-Cox Log-rank test shows the Compound 24 survival curve to be significant with a p-value of 0.0013 for Influenza A / Wisconsin / 15 / 2009 (H3N2). Compound 24 IN against A / California / 07 / 2009(H1N1) 15 pdm09 showed 100% survival in contrast to 40% of the oseltamivir phosphate group and 0% in the vehicle control group. A Mantel-Cox log-rank test shows the Compound 24 survival curve to be significant with a p-value of 0.0006 for A / California / 07 / 2009 (H1N1pdm09) strain Compound 24 against influenza B showed 100% survival in contrast to 0% in the vehicle control group. In the oseltamivir phosphate-treated group, 40% were euthanized 20 before the study ended as they lost more than 25% of their initial weight during the two-week study period. A Mantel-Cox log-rank test shows the Compound 24 survival curve to be significant with a p-value of 0.0065 for the B / Brisbane / 60 / 2008 Strain.

[0291] In addition, Compound 24 IN appeared to provide a better quality of life for infected mice as no large changes in body weight were detected. Weight loss was observed in all other 25 treatment groups. FIG.14A shows the corresponding viral lung titers.

[0292] METHOD EXAMPLE 9. Efficacy against Influenza A / Hong Kong / 2369 / 2009 (H1N1pdm09, Tamiflu® Resistant) (FIG. 15A and FIG. 15B): The efficacy of Compound 24 IN was tested in a mouse model against a representative Influenza A strain – A / Hong Kong / 2369 / 2009 (H1N1pdm09, Oseltamivir [Tamiflu®] Resistant), a pandemic 30 strain of H1N1 that represents a large portion of the seasonal flu burden every year that is also resistant to Tamiflu®. All mice were first infected with 10x LD50of the A / Hong Kong / 2369 / 2009 (H1N1pdm09, Oseltamivir [Tamiflu®] Resistant) strain of influenza virus. At infection IVIG (6 g / kg) was administered to the Compound 24 IN and Vehicle groups via intraperitoneal injection (IP) to simulate human levels of anti-DNP and anti-rhamnose - 65 -70849-04 antibody titers.

[0293] Treatment began at 24 hpi (1 dpi). Mice receiving either 2.2 mg / kg of Compound 24 IN or a vehicle control were first anesthetized with isoflurane. Each mouse then received 0.25 mL / kg of vehicle intranasally or 0.25 mL / kg of Compound 24 IN to each nostril, then 5 released back into their cage. Mice receiving Tamiflu® (oseltamivir phosphate) were administered 5 mg / kg via oral gavage, then released back to their cage.

[0294] At 24 h after treatment, three mice from each group were selected, euthanized, and the lungs were collected and snap frozen in liquid nitrogen. Lungs were homogenized and a TCID50 assay was performed in triplicate on MDCK cells looking for cytopathic effects and 10 the virus titer were calculated using the Reed-Muench method.

[0295] The remaining mice were observed and weighed daily during the two-week study period, at which point they were sacrificed. Mice that lost 25% of their initial weight at any timepoint during the study were euthanized according to IACUC protocol.

[0296] As shown in FIG.15A, Compound 24 IN was shown to provide protection against 15 influenza A strain – A / Hong Kong / 2369 / 2009 (H1N1pdm09, Oseltamivir Resistant) by the complete elimination of detectable virus titer and the survival of all mice out to study completion (Day 14). The oseltamivir and vehicle-treated mice were found to contain comparable high viral titers in collected lung samples 24 h post-drug administration (~2x106 TCID50) as shown in FIG. 15C, and all mice in these groups (but not in the Compound 24 20 IN group) were sacrificed by Day 7 due to a body weight loss of >25%, as shown in FIG. 15B. A Mantel-Cox log-rank shows the Compound 24 survival curve to be significant with a p-value of 0.0009 for the influenza A strain – A / Hong Kong / 2369 / 2009 (H1N1pdm09, Oseltamivir Resistant).

[0297] METHOD EXAMPLE 10. Compound 24 Prevention of Transmission of H1N1 25 (FIG. 16): Compound 24 IN was evaluated for its ability to prevent transmission of influenza. It was found that a single dose of Compound 24 IN outperformed vehicle control. For this study, guinea pigs were infected with human H1N1 influenza and received 4g / kg IVIG intraperitoneally. Then the guinea pigs were treated 24 h post-infection with vehicle, or 4 mg / kg intranasally of Compound 24 IN. Twenty-four h after treatment, infected guinea 30 pigs were cohoused with naïve guinea pigs for 14 days. Nasal swabs were taken every other day, and viral RNA was measured using PCR. At the end of the study, anti-neuraminidase and anti-hemagglutinin antibody titers were measured to assess influenza exposure.

[0298] The results are shown in FIG.16. In the group treated with vehicle, all naïve co- housed animals became infected by day 4, and infection was confirmed by increased antibody - 66 -70849-04 titers. In the Compound 24 IN treatment group only 1 of the 10 naïve co-housed guinea pigs became infected, and not until day 8, which was confirmed by seropositivity of anti- hemagglutinin and anti-neuraminidase. The data suggest that not only did Compound 24 IN protect 90% of the guinea pigs in this prolonged exposure transmission model, the 5 transmission was also delayed in the one instance of transmission relative to vehicle transmission.

[0299] Mitigating viral shedding through reduced transmission is believed equally important to symptom management in public health interventions. While symptomatic relief can improve patient well-being, it may inadvertently lead to a resumption of normal activities 10 during the infectious phase. These data suggest that a single dose treatment with Compound 24 reduces secondary infection rates of human H1N1 by 90%.

[0300] METHOD EXAMPLE 11. Compound 24 Mutation Emergence (FIG. 17A and FIG.17B): Compound 24 IN was evaluated for its ability to produce drug-resistant mutants of influenza A virus (IAV) after serial passaging the virus in the presence of Compound 24. 15 Traditionally, drug resistance emergence studies are performed in vitro to streamline experimental design and quickly identify mutations. However, due to the immunological dependent nature of Compound 24, the mutation emergence study described here was performed in vivo to more rigorously test whether Compound 24 produces drug-resistant IAV in conjunction with a functioning immune system. Furthermore, due to the potency of 20 Compound 24 in eliminating nearly all traces of IAV, a sub-optimal dose was necessarily used to maintain measurable viral load and encourage mutation during passaging. It was found that an 81 #g / kg dose of Compound 24 could reduce, but not eliminate, IAV infection in mice and was therefore chosen as the sub-optimal dose.

[0301] Three groups of five mice each were used for each passage cycle. All groups received 25 10 LD50 influenza virus A / PR8 / 34 (H1N1). Group 1 was administered a single dose of 81 #g / kg of Compound 24 intranasally 48 h post-infection. Group 2 was administered vehicle (20mg / ml Avicel, 6mg / ml DDM, 1x PBS, pH 7.4) once intranasally, 48h post-infection. Group 3 was administered 5 mg / kg of oseltamivir phosphate twice daily orally for 2 days starting 48h post-infection. Twenty-four hour post-infection IVIG (6 g / kg) was administered 30 to the Compound 24 IN and vehicle groups via intraperitoneal injection (IP) to simulate human levels of anti-DNP and anti-rhamnose antibody titers. Body weight and survival monitoring was recorded each day, and each group was sacrificed 4 days after drug administration for viral titer determination by TCID50and RNA extraction from lung tissue. After titer determination to maintain consistent 10 LD50infections between passages, the - 67 -70849-04 process was repeated for each consecutive cycle.

[0302] It was found that Compound 24 IN does not produce viable drug-resistant mutants after 5 passages and was shown to maintain efficacy with a modest ~1.5-fold decrease in IC50 from ~12 nM to 20 nM as seen in neuraminidase inhibition assays (NIA), as shown in FIG. 5 17B. In contrast, oseltamivir phosphate treatment during IAV passaging resulted in a >1,500- fold decrease in NAI efficacy, from ~2 nM (Hong, B. T., et al. Oseltamivir hydroxamate and acyl sulfonamide derivatives as influenza neuraminidase inhibitors. Bioorganic & medicinal chemistry 2014, 22(23), 6647–6654) to ~3,000 nM. These results suggest that Compound 24 does not encourage the emergence of drug-resistant mutations in vivo, even at sub-optimal 10 doses like oseltamivir does. Moreover, Compound 24 was shown to maintain NIA efficacy during the duration of the study, while the efficacy of the industry standard oseltamivir was significantly impaired. Additionally, when an LD50study was run on the mutants after 5 cycles it was found the LD50 of the Tamiflu® treated mice showed a 4,000-fold increase in virulence compared to a 4-fold increase in Compound 24 treated, mice, as shown in FIG. 15 17A. Altogether, this study suggests that extended use of Compound 24 would not encourage the emergence of drug-resistant IAV mutants.

[0303] METHOD EXAMPLE 12. Compound 24 IN Avian Influenza efficacy (FIG.18A and FIG. 18B): Three groups of mice (n=4 / cohort) were infected with a labeled version of the avian flu currently spreading in Texas - rH5N1 Nluc A / Texas / 37 / 2024 with 10E2 20 PFU / mouse. A fourth group was mock infected with viral infection media containing no virus as a negative control. Mice were treated with 2mg / kg of Compound 24 IN intranasally, or 5 mg / kg BID for 5 days of Tamiflu® orally or Compound 24 vehicle intranasally. Mice were serially imaged with an IVIS imager to track the luminescence of the virus to quantify the viral load. At Day 6, Compound 24 IN treated mice had almost no 25 virus left in their body after a single dose while Tamiflu® had much higher amounts. The mice were sacrificed, and the viral load was quantified in each via TCID50 assay. The viral load in the lungs of the Tamiflu® treated mice was found to be significantly higher than in the Compound 24 IN treated mice, suggesting that even at very low doses, Compound 24 is effective at clearing avian influenza infections, including high pathogenic avian influenza 30 infections. FIG.18A shows the images of Groups 1 and 2 and FIG.18B of Groups 3 and 4.

[0304] METHOD EXAMPLE 13. Pharmacological Mechanism of Action of Compound 24: The mechanism of action of Compound 24 is evaluated by the ability to recruit sufficient naturally occurring anti-hapten antibodies to mediate antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement - 68 -70849-04 dependent cytotoxicity (CDC) induced killing of virus-infected cells. Human embryonic kidney cells (HEK293) are modified to express influenza neuraminidase (HEK293-NA), mimicking influenza-infected cells. Compound 24 is evaluated for the ability to activate specific immune system components (Fc!RIIIa, Fc!RIIa) in effector cells and the 5 complement system. If activated, these components are expected to trigger ADCC, ADCP, and CDC, ultimately killing the HEK293-NA cells. A control group using unmodified HEK293 cells (HEK293-WT) is used for comparison. The HEK293-N1-neuraminidase cell cultures are also supplemented with or without human anti-DNP antibody and incubated with serial dilutions of Compound 24. 10

[0305] As shown in the figures of FIG.19, Compound 24 is effective in mediating ADCC (FIG. 19A), and ADCP (FIG.19B) of the neuraminidase-transduced HEK293 cells, displaying the anticipated bell-shaped dependence on Compound 24 concentration as detected through changes in luminescence because of activation of the human FcgRIIIa expressing effector cells using a Promega ADCC kit. Cell death can be blocked by either 15 deletion of IVIG or the absence of neuraminidase on the target cell-surface, suggesting that ADCC-mediated and ADCP-mediated killing rely on two key elements: 1) the presence of anti-hapten antibodies and 2) cell-surface expression of influenza neuraminidase. The dependence upon cell-surface expression of influenza neuraminidase is an important safety attribute, suggesting that uninfected cells should not be damaged by Compound 24. 20

[0306] As shown in FIG.19C, Compound 24 is also found to promote CDC-mediated killing of neuraminidase expressing target cells. Cell death is blocked by introducing a 100- fold excess of free zanamivir, suggesting that Compound 24-mediated activation of CDC- mediated killing should also be limited to cells / virions that express viral neuraminidase.

[0307] The data in the figures of FIG.19 validate the immune activity of Compound 24 and 25 demonstrate that Compound 24 can recruit naturally occurring anti-hapten antibodies to activate ADCC-mediated (Panel A), ADCP-mediated (Panel B), and CDC-mediated (Panel C) killing of influenza-infected cells. Compound 24-mediated killing is dependent on the presence of both anti-hapten antibodies and viral neuraminidase on the target cell-surface, which is a desirable safety feature. - 69 -70849-04

[0308] METHOD EXAMPLE 14. Neuraminidase Inhibition Activity of Compound 24 IN Against Seasonal and Drug-resistant Influenza A and B Strains (FIG.20): The neuraminidase inhibition activity of Compound 24 IN is evaluated against 4 seasonal influenza strains (A / PR / 8 / 1934 (H1N1), A / California / 07 / 2009 (H1N1pdm09), 5 A / Wisconsin / 15 / 2009 (H3N2), and B / Brisbane / 60 / 2008 (Victoria Lineage)) and 2 drug- resistant influenza virus strains (A / Hong Kong / 2369 / 2009 (H1N1pdm09, oseltamivir- resistant), and A / Illinois / 37 / 2018 (H1N1pdm09, baloxavir-resistant)). Neuraminidase inhibition activity is measured based on the IC50in relative fluorescence unit (RFU) of the enzymatic product resulting from neuraminidase activity of the virus particles. 10

[0309] The IC50 against all six strains are shown in FIG.20. Compound 24 is found to inhibit neuraminidase activity of the three seasonal influenza A strains with IC50 ranging from 12.7-16.4 nM. Compound 24 also inhibits neuraminidase activity of the seasonal influenza B strain (Victoria Lineage) with an IC50 of 34.5 nM. Compound 24 is found to effectively inhibit the neuraminidase activity of oseltamivir-resistant and baloxavir-resistant flu strains 15 with an IC50 of 17.9 and 27.2 nM, respectively.

[0310] METHOD EXAMPLE 15. Neuraminidase Inhibition Activity Against Influenza A / PR / 8 / 1934 (H1N1): A 10-fold serial dilution of test compounds were prepared in 1X NA- FluorTMAssay Buffer. The 4x dilution series and diluted virus samples were added into the corresponding wells in a black, 96-well, clear flat bottom plate. The plate was incubated on a 20 plate shaker for 30 min at 37°C.200 µM NA-FluorTMSubstrate working solution was added and incubated on a plate shaker for an additional 1 hr at 37°C to detect the viral neuraminidase activity. The reaction was terminated by a stop solution (60% NA-FluorTMStop Solution / 40% ethanol). The fluorescence signal was detected with an excitation wavelength of 350 nm and an emission wavelength of 440 nm by BioTek Synergy Neo2 HTS 25 Multi-Mode Microplate Reader. Data were analyzed using GraphPad Prism 10 to determine the half-maximal inhibitory concentration (IC50) of the test compound. Activity in this assay demonstrates that the tested conjugates retained the direct antiviral activity of the ligand after being conjugated to the linker and two haptens. The IC50 values for the tested compounds are shown in the following table.- 70 -70849-04

[0311] METHOD EXAMPLE 16. Viral Cytopathic Effect Inhibition Activity of Compound 24: In the presence of viral infections, host cells undergo changes at the cellular level in response to infection. This phenomenon is known as the cytopathic effect (CPE). The effectiveness of Compound 24 in preventing CPE caused by an influenza virus infection and 5 its associated cytotoxicity was determined through a viral CPE-inhibition assay. Virus stock titers were measured by performing a TCID50 to determine the viral inoculation required for the CPE inhibition assay.

[0312] Cell viability from the viral CPE inhibition assay was quantified with neutral red staining to calculate the EC50of Compound 24 against 4 wild-type (A / PR / 8 / 1934 (H1N1), 10 A / Wisconsin / 629-D00015 / 2009 (H1N1pdm09), A / Hong Kong / H090-756-V1(0) / 2009 (H3N2), and B / Brisbane / 60 / 2008 (Victoria Lineage)) and 1 drug-resistant influenza strains (A / Hong Kong / 2369 / 2009 (H1N1pdm09, oseltamivir-resistant).

[0313] The summary of Viral CPE Inhibition of Compound 24 Against Wild-Type and Drug-Resistant Strains is shown in the following table.15

[0314] Compound 24 effectively prevented CPE induced by H1N1 and the oseltamivir- resistant strain (EC50 < 0.9 µM). Compound 24 also inhibited CPE of H1N1pdm09, H3N2, and influenza B with EC50 < 8 µM. It is important to note that these experiments only consider the activity of the zanamivir moiety, and Compound 24 is expected to have greater 20 than 1,000-fold activity when the immune system can be recruited in vivo. - 71 -70849-04

[0315] METHOD EXAMPLE 17. Efficacy against Avian Influenza: The efficacy of Compound 24 against the A / Duck / MN / 1525 / 81 (H5N1), A / HK / 61 / 2016 (H7N9), and A / Vietnam / 1203 / 2004 (H5N1) strains of avian influenza was evaluated in vitro. Cells were cultured and then exposed to varying dilutions of Compound 24 and an Avian strain. 5 Cytopathic effects were observed microscopically, measured with a red dye and EC50 (concentration of 50% CPE inhibition) values were calculated, as shown in the following table.

[0316] It was found that Compound 24 inhibits H5N1 and H7N9-induced cytopathic effect and production of nascent virions in vitro with single digit micromolar potency. Additionally, 10 the results confirm the direct-acting antiviral property of Compound 24 against the avian influenza strains. The direct antiviral action of Compound 24 was also validated in vivo, where very low doses of Compound 24 were 100% protective against the Texas 2024 isolated H5N1.

[0317] METHOD EXAMPLE 18. Efficacy against A / Illinois / 37 / 2018 (H1N1, Baloxavir 15 Resistant): Baloxavir treatment has very high mutation emergence rate and presents a clinical issue for baloxavir use. Mice were infected with 10LD50 of mouse adapted A / Illinois / 37 / 2018 (H1N1pdm09, baloxavir resistant) in a pilot efficacy study against baloxavir mutants. As shown in FIG.21, mice that were treated with Compound 24 had 100% survival. The vehicle control and baloxavir treatment groups had similar survival rates 20 suggesting no efficacy from baloxavir. Compound 24 may be useful in treatments against baloxovir resistant strains of influenza.

[0318] METHOD EXAMPLE 19. Compliment Dependent Cytotoxicity (CDC) Assay: Neuraminidase expressing HEK293 cells (HEK293-NA) were plated at 10,000 cells per well in a 96-well poly-D lysine coated, white-walled plate. The cells were allowed to incubate 25 overnight at 37°C, aiming for 50% confluency on the day of the assay. Serial dilutions of compound were prepared in DMEM, adjusted to be 4x higher than the target concentration. The cells were washed with 200 µL of PBS, followed by the addition of 25 µL of DMEM per well.25 µL of the serially diluted compounds were added to each well, and the plates were - 72 -70849-04 then incubated at 37°C for 30 minutes. Rabbit anti-DNP (Invitrogen, cat: A6430) or rabbit anti alpha-gal (Enzo m86) was diluted to 40 µg / mL and rabbit complement (Sigma Aldrich, cat: S7764) was diluted to 20%.50 µL of this mixture, was added to the cells for a final concentration of 20 µg / mL rabbit anti-DNP and 10% rabbit complement. The cells were 5 incubated at 37°C for 4 hours. After the incubation period, the cells were washed twice with 200 µL PBS. Subsequently, 200 µL of Cell Titer-Glo reagent (Promega, cat: G7570) in PBS was added to each well. Luminescence was measured using a plate reader equipped with glow-type luminescence read capabilities. The percent cell death was calculated and plotted, giving a bell-shaped curve. In the lower concentration range, the compound stimulates the 10 complement proteins to kill cells. In the higher concentration range, the compound blocks complement activity by saturating the receptors on to the target protein and the antibodies. Activity in this assay demonstrates the effective ability of the full conjugate to bind to the target viral protein and recruit the immune system with the other domain of the molecule. EC50 values for both the low concentration range and the high concentration ranges for the 15 tested compounds in the following table.

[0319] METHOD EXAMPLE 20. Summary of Nonclinical Pharmacokinetics and Metabolism: The pharmacokinetics (PK) of Compound 24 were characterized in BALB / c mice across four routes of administration: intravenous (IV), subcutaneous (SC), oral, and IN. 20 While IV and SC have the highest level of drug absorbed, IN was chosen as a preferred route of administration (ROA) for ease of administration in human patients. PK studies were also conducted in mice to determine the minimum pharmacologically active dose (PAD).

[0320] After IN administration, Compound 24 demonstrates rapid absorption across species with a time to maximum plasma concentration (Tmax) ranging from approximately 0.42 to 25 1.10 hours in preclinical PK studies. The bioavailability (F) of Compound 24 is dose- and formulation-dependent and was found to be highest at clinically relevant dose levels in rodents. At similar doses and across formulations, mean F was moderate to high in mouse - 73 -70849-04 (21% - ~100%), low to moderate in rat (~20% - ~50%), and low (4% - ~20%) in dogs. In each instance, the higher F was a concentration that was £10% the maximum feasible dose (MFD) and the lower range F is the MFD. The mean elimination half-life (t1 / 2) ranged from 0.603 to 6.81 hours (0.603 to 4.2 hours excluding a single outlier) with escalating IN doses in 5 rats. These data suggested that absorption had become rate-limiting in the in vivo elimination of Compound 24 (i.e., flip-flop kinetics). In dogs, the mean t1 / 2estimate was ~1 hr after IV and IN administration at doses up to ~20 mg / kg. The Day 14 / 1 ratios for Cmaxand AUC0-24were close to 1 in rats and dogs, indicating there is no accumulation following once daily administration. Compound 24 was found to have low cellular permeability and is not a 10 substrate of human P-glycoprotein (P-gp).

[0321] Compound 24 showed low to moderate plasma protein binding. The percentage of unbound Compound 24 ranged from 74.0% to 89.4% across mice, rats, dogs, monkeys, and humans with human plasma showing the highest binding. Partitioning work indicated that Compound 24 had blood to plasma ratios less than or equal to 0.72, suggesting limited 15 partitioning into red blood cells. Compound 24 was metabolically stable across various species in vitro. Profiling pooled rat plasma detected an apparent minor circulating metabolite (0.71%) resulting from amide hydrolysis (M1160), with intact Compound 24 appearing to be the predominant circulating entity.

[0322] Compound 24 did not directly (reversibly) inhibit the major human cytochrome 20 P450s (CYPs) 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4 / 5. In addition, coincubation with Compound 24 did not result in time dependent inhibition (TDI) of these same CYPs. Thus, Compound 24 is not expected to perpetrate a CYP-mediated drug-drug interaction.

[0323] METHOD EXAMPLE 21. Summary of Nonclinical Safety Pharmacology and Toxicology: Safety pharmacology studies were conducted to identify any unintended effects 25 on organ systems acutely critical for life including the central nervous system (CNS), cardiovascular, and respiratory systems. Compound 24 had no effects on these organ systems. Additionally, there were no changes in electrocardiogram (ECG) parameters in dogs administered Compound 24 for 14 days in a GLP toxicology study.

[0324] Compound 24 was not mutagenic in a bacterial reverse mutation (Ames) test or an in 30 vitro micronucleus assay in vitro. Compound 24 absorbs light between 290 and 700 nm, with an absorption maximum at 360 nm.

[0325] Non-GLP dose tolerability studies at the MFD were conducted in rats and dogs to support dose selection for 14-Day GLP toxicology studies. In rats, the MFD was 100 mg / kg by the IN route, the intended route of clinical administration. A dose of 100 mg / kg was well - 74 -70849-04 tolerated in the single dose tolerability phase. The 100 mg / kg dose was selected for further evaluation across a 3-day tolerability study with daily dosing. There were no effects of treatment on standard in-life and post-life assessments, which supported the selection of 100 mg / kg as the high dose for a 14-day GLP study. In the 14-day study, rats were administered 5 vehicle or doses up to 100 mg / kg / day by the IN route. There was no morbidity or mortality, no effect of treatment on any in-life assessments including clinical observations, body weight, food consumption, ophthalmology, CNS (Functional observational battery (FOB)), or clinical pathology parameters (hematology, coagulation, chemistry, urinalysis) and no effect on post- life assessments, including necropsy, organ weights and microscopic examination of a 10 standard list of tissues. Accordingly, the NOAEL was 100 mg / kg / day in male and female rats dosed daily by the IN route for 14 days.

[0326] In dogs, the MFD by the IN route was 10 mg / kg. Consequently, to evaluate the potential systemic toxicity of Compound 24, exposures were increased by supplementing the IN dose with a 10 mg / kg SC dose administered simultaneously. A combined dose of 20 15 mg / kg was well tolerated in the single dose tolerability phase. The combined 20 mg / kg dose was selected for further evaluation across a 3-day tolerability study with daily dosing. There were no effects of treatment on standard in-life and post-life assessments, which supported the selection of 20 mg / kg as the high dose for a 14-day GLP study. In the 14-day study, dogs were administered vehicle or doses up to 20 mg / kg / day. There was no morbidity or mortality, 20 no effect of treatment on any in-life assessments including clinical observations, body weight, food consumption, ophthalmology, ECGs, or clinical pathology parameters (hematology, coagulation, chemistry, urinalysis) and no effect on post-life assessments, including necropsy, organ weights and microscopic examination of a standard list of tissues. Accordingly, the NOAEL was 20 mg / kg / day in male and female dogs dosed daily by the combined IN and SC 25 routes for 14 days.

[0327] METHOD EXAMPLE 22. Summary of Chemistry, Manufacturing, and Controls: Compound 24 is a small molecule neuraminidase inhibitor covalently conjugated to dinitrophenyl (DNP) and ^-L-rhamnose with PEG-based linkers. Compound 24 is manufactured in a four-step process from key starting materials and has been manufactured in 30 batches up to 100g. The structure, including the absolute stereochemistry of 11 chiral centers is confirmed through analysis by infrared spectroscopy (IR), Ultraviolet-Visible Absorbance Spectroscopy, High-resolution Mass Spectrometry (HRMS), Elemental Analysis, and 1-D / 2- D Nuclear Magnetic Resonance (NMR) spectroscopy. Compound 24 is packaged in HDPE plastic bottles protected from light and stored at -20°C±5°C for up to 12 months. - 75 -70849-04

[0328] METHOD EXAMPLE 23. Single-dose pharmacokinetics of compound 24 after intravenous (IV), subcutaneous (SC), and intranasal (IN) administration in mice: Female BALB / c mice were randomly assigned and dosed with Compound 24 according to the following groups: 5 1. IV at 2.22 mg / kg in PBS 2. IN at 2.2 mg / kg in PBS 3. IN at 0.24 mg / kg in 20 mg / mL Avicel® RC 591 , 6 mg / mL DDM in 1X PBS 4. IN at 0.24 mg / kg in PBS 5. IN at 2.2 mg / kg in 20 mg / mL Avicel® RC 591 , 6 mg / mL DDM in 1X PBS 10 6. SC 2.2 mg / kg in PBS

[0329] Sparse sampling was employed (n=3 / timepoint / dose group). The PK findings are summarized in Table 1. Following IV administration, the clearance (CL) was low relative to the hepatic blood flow (Qh) in a mouse (e.g., ~18%; Table 1). The mean volume of distribution at steady state (Vss) was higher than plasma volume but lower than total body 15 water for a mouse, suggesting limited distribution into tissues. The corresponding t1 / 2 was short (<1 hr).

[0330] After IN administration in PBS, Compound 24 was readily bioavailable (F=47.8%) compared with IV. The absorption was rapid with an observed Tmaxof approximately 30 minutes. When dosed IN with a formulation including Avicel® (thickener) and DDM 20 (permeability agent), the exposure when measured by Cmaxand AUC is comparable to SC administration, suggesting that Compound 24 is readily absorbed by either ROA. This improved IN formulation doubled the F when compared with PBS IN administration (47.8% vs. 110%).

[0331] Finally, the 0.24 mg / kg IN dose was shown to have good exposure. The AUCinf25 increase between 0.24 and 2.2 mg / kg in the Avicel / DDM formulation was trending greater than dose proportional but given the sparse sampling, the significance of this trend was unknown. Table 1: PK Comparison of IN and SC Compound 24 in Mice Using Different Formulations- 76 -70849-04

[0332] METHOD EXAMPLE 24. Pharmacokinetics after single IV and IN administration in Sprague Dawley rats. The PK of Compound 24 was determined following single IV and IN administration of Compound 24 to female SD rats (n=3 per dose 5 group, serial sampling) to identify the impact of different Compound 24 formulations on the PK exposure profile of Compound 24 when dosed IN versus IV. Broad classes of excipients commonly used in nasal formulations were examined, including thickeners, mucoadhesives, solubility agents, and permeability agents.

[0333] Following a single IV dose of 1 mg / kg Compound 24 to female SD rats, the 10 elimination t1 / 2of Compound 24 was short (<1 hr). The VSSwas higher than rat serum volume but lower than total body water at 0.202 L / kg, indicating that Compound 24 was not extensively distributed in rats (10). Compound 24 was cleared slowly relative to rat Qh (10) with a mean CL of 9.43$mL / min / kg. (Table 2)

[0334] Through the IN route, exposure (Cmax, AUCinf) increased with increasing dose; 15 however, the increases were less than dose proportional. All t1 / 2 by IN were longer than found by IV, suggesting absorption becomes rate limiting in the elimination of Compound 24 (e.g., flip-flop kinetics). Finally, systemic exposure achieved was equivalent with and without Avicel as a thickener (Table 2), suggesting that DDM alone is sufficient to obtain the exposure levels desired. $ 20 Table 2: Mean (± SD) Pharmacokinetic Parameters of Compound 24 in Female SD Rats following Single IV and IN Doses of 1, 10 and 100 mg / kg Compound 24aA single aberrant time point or an unexpectedly high value at 24 hours in a single rat results in a half-life of 13.81 hours for one animal, causing the group average half-life to be reported - 77 -70849-04 as 6.81h. Exclusion of this single data point as an outlier results in a calculation of 4.2 hours, which is closer to the expected half-life.

[0335] METHOD EXAMPLE 25. Pharmacokinetics after single IV and IN administration in dog. The PK parameters of Compound 24 were determined following 5 single IV and IN administration of Compound 24 to male beagle dogs (n=3 per dose group). Serial sampling was employed. The actual doses of 2.06 mg / kg IV and 2.46 or 24.6 mg / kg IN were administered using solutions / suspensions. Groups were tested to compare IN vs IV, to test the necessity of a thickener in the nasal formulation, to explore the optimal concentration of DDM, and to examine PK profile after administration with a nasal device compared with a 10 pipette.

[0336] Following a single IV dose of 2.06 mg / kg Compound 24 to male beagle dogs, the t1 / 2of Compound 24 was short with a mean value of 0.802 hr. The mean VSSwas higher than dog serum volume but was lower than total body water at 0.193 L / kg (10), indicating that Compound 24 was not extensively distributed in dogs. Compound 24 was cleared slowly 15 relative to dog Qh with a mean CL of 3.43 mL / min / kg. (9)

[0337] Following single IN doses of 2.46 and 24.6 mg / kg Compound 24 to male beagle dogs, absorption of Compound 24 was rapid with a tmax of 0.500 hr for both dose levels. t1 / 2 is similar across dose levels and routes of administration, suggesting absorption was not rate limiting in the elimination of Compound 24 in the dog. Exposure (Cmax, AUCinf) increased 20 with increasing dose; but not dose proportionally. Mean F was low (< 10%) after IN doses of 2.46 and 24.6 mg / kg. (Table 3)

[0338] When Compound 24 was administered through the IN route using either a Unispray Single-use nasal device or a pipette, no significant difference was seen in PK parameters suggesting that spray pattern is not a significant effector of absorption. 25

[0339] To determine the effects of varying the DDM concentration, a group of dogs received a single Compound 24 dose of 10 mg / kg with either 1.5 mg / mL or 6 mg / mL DDM in PBS. The higher DDM concentration performed better than the lower concentration. (Table 4). Table 3: Mean (± SD) Pharmacokinetic parameters of Compound 24 in beagle dogs 30 following single IV and IN doses of 1, 2.46 and 24.6 mg / kg Compound 24- 78 -70849-04Table 4: Mean (± SD) Pharmacokinetic parameters of Compound 24 in female beagle dogs following single IN doses of 2 and 10 mg / kg compound 24 using the Unispray Device or via pipette5

[0340] METHOD EXAMPLE 26. A Phase I / IIa, Randomized, Double-Blind, Placebo- Controlled, Single-Dose and Single-Dose Challenge Study to Assess the Safety, Tolerability, Pharmacokinetics, and Efficacy of Intranasal Compound 24 in Healthy Volunteers and in Influenza Challenge Participants: 10

[0341] This was a First-in-Human (FIH), Phase I / IIa, placebo-controlled, randomized, double blind, single center, single ascending dose (SAD) study to evaluate the safety, tolerability, Pharmacokinetics (PK), Pharmacodynamics (PD), and efficacy of Compound 24 intranasally administered to adult participants. The study consisted of 2 parts: an SAD part (Part 1) and an influenza challenge part (Part 2). Compound 24 was prepared for the Phase I / IIa study as a 15 solution intended for a nasal administration in dosage strengths ranging from 2.5 mg / mL to 250 mg / mL. In addition to the active ingredient Compound 24, the clinical formulation contained the following excipients: Up to 6 mg / mL N-Dodecyl-Beta-D-Maltoside (DDM) and 1x Phosphate-Buffered Saline (PBS). Compound 24 was administered intranasally using an Aptar Unidose nasal device. 20

[0342] The objectives and endpoints of the study are set forth in Tables 5 and 6. Table 5 - Part 1 (SAD)- 79 -70849-04Table 6 - Part 2 (Influenza Challenge)- 80 -70849-04Part 1 (SAD)

[0343] Part 1 evaluated the safety, tolerability, PK, and PD of SADs of Compound 24 in up to 3 dose levels in 3 cohorts.

[0344] In each cohort, 8 healthy participants were randomized to receive a single dose of 5 Compound 24 or placebo intranasally at an active to placebo ratio of 3:1. The given dose levels are presented in Table 7 below. Table 7

[0345] A sentinel approach was used in all cohorts. In each cohort, 2 sentinel participants 10 received study intervention on the same day. The 2 sentinel participants were randomized at an active to placebo ratio of 1:1 and the remaining 6 participants at an active to placebo ratio of 5:1.

[0346] The screening visit was performed between Day -28 to Day -2. Eligible participants visited the clinical site in the morning of Day -1 for assessment of clinical laboratory tests 15 and urinalysis, were admitted to the clinical site in the evening of Day -1, and were discharged at the discretion of the investigator after performing the last assessment on Day 2. A follow-up visit and phone call were performed on Day 7 (±2) and Day 28 (±2), respectively.

[0347] The total duration of involvement for each participant was up to approximately 8 20 weeks. - 81 -70849-04

[0348] The end of Part 1 of the study was defined as the last contact with the last participant. Part 2 (Influenza Challenge)

[0349] Part 2 evaluated the safety, tolerability, PK, PD, and efficacy of single doses of 5 Compound 24 following an influenza challenge in up to 2 dose levels in 2 planned cohorts.

[0350] In each cohort, 30 healthy participants were randomized to receive Compound 24 or placebo intranasally at an active to placebo ratio of 2:1. After randomization, participants were inoculated with 1.0×106TCID50 / mL Influenza Type A Virus (A / Belgium / 4217 / 2015 H3N2) on Day 1 and approximately 24 h after inoculation, they received a single dose of 10 either Compound 24 or placebo.

[0351] The dose levels are presented in Table 8 below. Table 8

[0352] The MNT test was performed from Day -42 to Day -3 and other screening tests from 15 Day -28 to Day -3. If the MNT test result was obtained before performing the other screening tests and was positive, no other screening tests were performed, and the participant was not included in the study. Between Day -28 and Day -3, the MNT test and the other screening tests could be performed on the same day.

[0353] Eligible participants were admitted to the clinical site in the morning of Day -2 and 20 were discharged at the discretion of the investigator after performing the last assessment on Day 11. A follow-up visit was performed on Day 28 (±2).

[0354] The participants were monitored for disease progression using FLU-PRO©. FLU- PRO©is a validated patient-reported questionnaire that assesses symptoms associated with influenza. It assesses symptoms across multiple body systems over the disease course. 25 Participants assessed any challenge virus or influenza-related signs and symptoms using the FLU-PRO©and the FLU-PRO©Additional Daily Diary. As part of the quantitative validation analyses of the FLU-PRO©, participants were required to complete additional diary items, the FLU-PRO©Additional Daily Diary Items. The additional questions were related to: Patient Global Rating of Flu Severity; Patient Global Assessment of Interference with Daily 30 Activities; Patient Global Assessment of Physical Health; Return to ‘Usual’ Health; and Return to ‘Usual’ Activities. The FLU-PRO©questionnaire was performed twice daily, once - 82 -70849-04 in the morning and once in the evening, approximately 12 h apart. The FLU-PRO©Additional Daily Diary was completed once daily in the morning. On Day 11, participants only reported in the morning prior to discharge.

[0355] Virus levels were measured throughout the study by nasopharyngeal swab samples 5 by qRT-PCR. All positive qRT-PCR tests had to be confirmed by TCID50.

[0356] The total duration of involvement for each participant was up to approximately 10 weeks.

[0357] The end of Part 2 of the study was defined as the last visit with the last participant. Study Population 10

[0358] A maximum of 122 participants were planned to be enrolled in the study: Up to 32 participants in Part 1 (SAD) and up to 90 participants in Part 2 (Influenza Challenge). Participants enrolled in one cohort could not be enrolled in another cohort.

[0359] In Part 1 (SAD), a total of 24 participants were randomized and treated with Compound 24: 6 participants received 30 mg Compound 24, 6 participants received 100 mg 15 Compound 24, 6 participants received 300 mg Compound 24, and 6 participants received placebo.

[0360] In Part 2, a total of 57 participants were randomized, treated, and received the challenge with the Influenza A Virus (Belgium / 4217 / 2015 H3N2): 20 participants received 30 mg Compound 24, 18 participants received 300 mg Compound 24, and 19 participants 20 received placebo. Eligibility Criteria Part 1 (SAD)

[0361] Healthy volunteers, between 18 and 65 years old at screening, extremes included, and having a body weight of at least 50.0 kg at screening, with a body mass index (BMI) 25 within the range of 18.5 to 32.0 kg / m2, extremes included, at screening. Part 2 (Influenza Challenge)

[0362] Healthy volunteers, between 18 and 55 years old at screening, extremes included, and having a body weight of at least 50.0 kg at screening, with a BMI within the range of 18.5 to 30.0 kg / m2, extremes included, at screening. Participants had to have pre-existing 30 antibodies to influenza virus H3N2 subtype, strain A / Belgium / 4217 / 2015, as determined by a MNT of &14 at screening.

[0363] If after 200 screened participants, the ineligibility rate based on MNT testing was above 75%, the MNT titer could be widened to &20. This did not affect participant safety or the validity of the study results as the participants needed to be able to be infected in order to - 83 -70849-04 test Compound 24.

[0364] Table 9 sets forth a summary of the intervention details for the challenge trial. Table 9 – Test Product, Dose, Mode of Administration, Batch Number(s)Study / Intervention duration 5

[0365] In Part 1 (SAD), each participant received a single dose of Compound 24 or placebo.

[0366] In Part 2 (Influenza Challenge), each participant received a single dose of Compound 24 or placebo after inoculation.

[0367] The total duration of involvement for each participant, screening through follow-up, 10 was approximately 8 weeks for Part 1 (SAD) and 10 weeks for Part 2 (Influenza Challenge). Study Evaluations Pharmacokinetics

[0368] Plasma samples were collected for the analysis of Compound 24 in plasma. For Part 1 and Part 2, the PK parameters were determined for Compound 24 by non-compartmental 15 analysis using the individual plasma concentration time profiles, with actual sampling times. Pharmacodynamics

[0369] Pharmacodynamic assessments were performed throughout the study, venous blood samples were collected for analysis of cytokines in serum and anti-hapten titer for both study parts and for the determination of the MNT, for Part 2 (Influenza Challenge) only. 20 Safety - 84 -70849-04

[0370] The study evaluated safety and tolerability through assessment of AEs, clinical laboratory tests, ECG, vital signs, pulse oximetry, physical examination, intranasal administration site examination, spirometry (Part 2 [Influenza Challenge] only), and peak flow measurements (Part 2 [Influenza Challenge] only). 5 Statistical Methods

[0371] No formal power calculation was performed because this study did not aim to test a statistical hypothesis, but aimed to explore the safety, tolerability, PK, and PD of a new molecule for the first time in humans while exposing a minimum number of adult participants. 10

[0372] Eight participants per cohort in Part 1 (SAD) (6 participants receiving Compound 24 and 2 participants receiving matching placebo) and 30 participants per cohort in Part 2 (Influenza Challenge) (20 participants receiving Compound 24 and 10 participants receiving matching placebo) were deemed sufficient.

[0373] An interim analysis was performed once all participants in Part 1 (SAD) had 15 completed follow-up or had discontinued earlier to develop topline data on the safety, tolerability, PK, and PD of Compound 24 to perform an IND submission. Results Participant Disposition Part 1 (SAD) 20

[0374] In Part 1, 66 participants were screened. In total, 24 participants were randomized and treated (safety analysis set): 6 participants in each cohort (Cohort 1, Cohort 2, Cohort 3, and placebo). All 24 participants completed Part 1.

[0375] Participants received the following treatments: • 6 participants in Cohort 1 received 30 mg Compound 24; 25 • 6 participants in Cohort 2 received 100 mg Compound 24; • 6 participants in Cohort 3 received 300 mg Compound 24; • 6 participants received placebo.

[0376] Table 10 sets forth the Part 1 treatment summary. Table 10- 85 -70849-04 n = number of participants in the safety analysis set with this observation Part 2 (Influenza Challenge)

[0377] In Part 2, 612 participants were screened. A total of 57 participants were randomized, treated, and received the challenge with the Influenza A Virus 5 (Belgium / 4217 / 2015 H3N2). All 57 participants completed Part 2.

[0378] Participants received the following treatments: • 20 participants in Cohort 1 received Influenza Challenge and 30 mg Compound 24; • 18 participants in Cohort 2 received Influenza Challenge and 300 mg Compound 24; • 19 participants received Influenza Challenge and placebo. 10

[0379] A total of 44 participants had a positive value for influenza virus at baseline after qRT-PCR and were included in the ITTi analysis set: 14 participants in the placebo group, 16 in Cohort 1, and 14 in Cohort 2.

[0380] Table 11 sets forth additional treatment summary characteristics for Part 1. Table 11n = number of participants in the safety analysis set with this observation 15 Demography and Baseline Characteristics Part 1 (SAD)

[0381] Overall, 17 (70.8%) participants were female, and 7 (29.2%) participants were male. The median age was 42.0 years (range 18 to 65 years), and the median BMI was 24.15 kg / m220 (range 20.0 to 29.6 kg / m2). All 24 (100%) participants were White. All participants were of non-Hispanic or -Latino ethnicity. The demographic characteristics were comparable across the different treatment groups, except for Cohort 3 where all participants were female and younger in age (median age of 30.0 years compared to 58.0, 46.5, and 45.0 years in the placebo group, Cohort 1, and Cohort 2, respectively). 25 Part 2 (Influenza Challenge)

[0382] Overall, 30 (52.6%) participants were male, and 27 (47.4%) participants were - 86 -70849-04 female. The median age was 43.0 years (range 28 to 55 years), and the median BMI was 25.30 kg / m2(range 19.4 to 30.5 kg / m2). The majority of the participants were White (52 [91.2%] participants). All participants were of non-Hispanic or -Latino ethnicity. The demographic characteristics were comparable across the different treatment groups. 5 Protocol Deviations

[0383] No major protocol deviations were reported in Part 1.

[0384] No major protocol deviations were reported in Part 2, except for one participant who was reported with the following deviation in the placebo group: viral challenge was not fully administered in the right nostril, due to incorrect positioning of the administration syringe. 10 Intervention Compliance

[0385] All study interventions and viral challenge agent were administered by trial-site personnel and witnessed by the investigator.

[0386] All participants received all planned doses of study intervention and viral challenge agent. 15 Efficacy Results Primary Efficacy Endpoint Viral Load AUC Based on qCulture

[0387] The primary objective for Part 2 (Influenza Challenge)was to assess the effect of single doses of Compound 24 on viral AUC compared to placebo in healthy participants 20 exposed to influenza H3N2 with positive predose values.

[0388] The mean log viral load AUC decreased with increasing Compound 24 doses. The mean (SE) log viral load AUC was 177.224± (42.105), 129.217± (38.371), and 95.300± (41.382) log10 TCID50 / mL×h for the placebo group, the 30 mg Compound 24 group (Cohort 1), and 300 mg Compound 24 group (Cohort 2), respectively. 25

[0389] The ANCOVA on the log viral load AUC showed statistical differences between the cohorts (p-value: 0.0247). There was a decrease in LS means versus placebo (-59.798 log10 TCID50 / mL×h after receiving 30 mg Compound 24 [Cohort 1] and -150.987 log10 TCID50 / mL×h after receiving 300 mg Compound 24 [Cohort 2]). Secondary Efficacy Endpoints 30 Viral Load AUC Based on qRT-PCR

[0390] The mean log viral load AUC decreased with increasing Compound 24 doses. The mean (SE) log viral load AUC was 642.234 (103.909), 514.982 (121.072), and 423.148 (121.862) log10vp / mL×h for the placebo group, Cohort 1, and Cohort 2, respectively. - 87 -70849-04

[0391] The ANCOVA on the log viral load AUC showed statistical differences between the cohorts (p-value: 0.0306). There was a decrease in LS means versus placebo (-136.042 log10 vp / mL×h after receiving 30 mg Compound 24 [Cohort 1] and -371.726 log10 vp / mL×h after receiving 300 mg Compound 24 [Cohort 2]). 5

[0392] Table 12 indicates the FLU-PRO©results from Placebo and Cohorts 1 and 2. The data show a statistically significant drop in symptom duration for the 300 mg cohort from 42 hours to 21 hours. The 30 mg dose demonstrated a trend toward a reduction in symptom duration. Table 12 – FLU-PRO©Results 10Pharmacokinetic Results Part 1 (SAD)

[0393] The PK of Compound 24 was studied in plasma up to 24 h post dose in healthy participants after receiving a single dose of 30 mg, 100 mg, or 300 mg Compound 24 15 intranasally.

[0394] The median tmax was 0.25 h, 1 h, and 3 h for the 30-mg, 100-mg, and 300-mg doses, respectively, which corresponded to the first time point after the last spray intake.

[0395] Compound 24 Cmax increased less than dose proportionally while Compound 24 AUCs increased dose proportionally over the 30-mg to 300-mg dose range. 20

[0396] Compound 24 t1 / 2was short and ranged between 2.35 h and 3.12 h, being slightly reduced with increasing doses. Table 13 – Summary of Plasma PK Parameters of Compound 24 and Dose Proportionality Assessment, Part 1N = number of participants; NA: not applicable - 88 -70849-04Values are geometric mean (geometric CV (%)), except for tmax: median (min; max) a: Slope for log transformed dose with its 90% CI from the power model (log-transformed PK parameter as dependent variable and the log-transformed dose as fixed effect). Part 2 (Influenza Challenge)

[0397] The PK of Compound 24 was studied in plasma up to 24 h post dose in healthy participants exposed to influenza H3N2 after receiving a single dose of 30 mg or 300 mg 5 Compound 24 intranasally.

[0398] The results were similar to those observed in Part 1 (SAD).

[0399] Median tmaxwas 0.25 h and 3 h for the 30-mg and 300-mg doses, respectively, which corresponded to the first time point after last spray intake.

[0400] Compound 24 Cmax increased less than dose proportionally while Compound 24 10 AUCs increased dose proportionally over the 30-mg to 300-mg dose range.

[0401] Compound 24 t1 / 2 was short with values of 2.38 h and 2.36 h for 30-mg and 300-mg doses, respectively. Summary of Plasma PK Parameters of Compound 24 and Dose Proportionality Assessment, Part 2N = number of participants; NA: not applicable Values are geometric mean (geometric CV (%)), except for tmax: median (min; max) a: slope for log transformed dose with its 90% CI from power model (log-transformed PK parameter as dependent variable and the log-transformed dose as fixed effect). Pharmacodynamic Results 15 Humoral Immunity: Microneutralization Assay

[0402] On Day -2, MNT was negative in 13 (68.4%) participants, 9 (45.0%) participants, and 5 (27.8%) participants in the placebo group, Cohort 1 (30 mg Compound 24), and Cohort 2 (300 mg Compound 24), respectively. At the follow-up visit, MNT was negative in 2 (10.5%) participants, 1 (5.0%) participant, and 0 participants in the placebo group, Cohort 1 20 (30 mg Compound 24), and Cohort 2 (300 mg Compound 24), respectively. - 89 -70849-04

[0403] On Day -2, median (min; max) MNT titer was 10.0 (10.0; 57), 10.0 (10; 453), and 10.0 (10; 57) in the placebo group, Cohort 1 (30 mg Compound 24), and Cohort 2 (300 mg Compound 24), respectively. At the follow-up visit, the median (min; max) MNT titer was increased to 113.0 (10; 905), 80.0 (10; 905), and 60.0 (10; 1280) in the placebo group, Cohort 5 1 (30 mg Compound 24), and Cohort 2 (300 mg Compound 24), respectively. The median MNT decreased with increasing Compound 24 doses. Cytokines Part 1 (SAD)

[0404] No relevant postbaseline changes or differences from placebo were observed for the 10 tested cytokines: IFN!, IL-10, IL-6, IL-8, and TNF. Part 2 (Influenza Challenge)

[0405] No relevant postbaseline changes or differences from placebo were observed for IL- 10, IL-6, IL-8, and TNF.

[0406] Values for IFN! increased relative to the pre-inoculation baseline in all groups, with 15 numerically smaller increases in the Compound 24 groups than in the placebo group. Safety Results Adverse Events

[0407] No deaths, other serious adverse events (SAEs), or treatment emergent adverse events (TEAEs) leading to discontinuation of the study, study intervention, or viral challenge 20 were reported during the study. Conclusion

[0408] After a single Compound 24 intranasal dose in healthy participants, Compound 24 tmax occurred at the first time point after last spray intake (median tmax: 0.25 h, 1 h, and 3 h for the 30-mg, 100-mg, and 300-mg doses, respectively). A less than dose-proportional increase 25 was observed for Compound 24 Cmax while Compound 24 AUCs increased dose proportionally. Compound 24 t1 / 2 was short, ranging from 2.35 h to 3.12 h. Similar results were observed in healthy participants exposed to influenza H3N2.

[0409] The results showed that intranasal administration of Compound 24 was generally safe and well tolerated in healthy participants and in participants who were inoculated with 30 1.0×106TCID50 / mL Influenza Type A Virus (A / Belgium / 4217 / 2015 H3N2).

[0410] The following publications, and each of the additional publications cited herein are incorporated herein by reference: - 90 -70849-04 (1) Kim, Y.; Hong, K.; Kim, H.; Nam, J. Influenza Vaccines: Past, Present, and Future. Rev. Med. Virol.2022, 32 (1), e2243. https: / / doi[dot] org / 10.1002 / rmv.2243. (2) Gubareva, L. V.; Fry, A. M. Baloxavir and Treatment-Emergent Resistance: Public Health Insights and Next Steps. J. Infect. Dis.2020, 221 (3), 337–339. https: / / doi[dot] 5 org / 10.1093 / infdis / jiz245. (1) McKimm'Breschkin, J. L. Influenza Neuraminidase Inhibitors: Antiviral Action and Mechanisms of Resistance. Influenza Other Respir. Viruses 2013, 7 (s1), 25–36. https: / / doi[dot] org / 10.1111 / irv.12047. (2) Moscona, A. Neuraminidase Inhibitors for Influenza. N. Engl. J. Med.2005, 353 10 (13), 1363–1373. https: / / doi[dot] org / 10.1056 / NEJMra050740.

[0411] The pharmaceutical compositions and methods of use and / or treatment described herein may be used with a number of different compounds such as those set forth in the following enumerated Embodiments A1-A74. The Embodiments A1-A74 describe various 15 features and aspects of the compounds used in the pharmaceutical compositions and corresponding methods of the disclosure. The following enumerated Embodiments A1-A74 are understood to illustrate many compounds which may be used in pharmaceutical compositions, methods of treatment with said compositions, and / or uses with said compositions of the disclosure: 20

[0412] Embodiment A1 relates to a compound of the formula: or a pharmaceutically acceptable salts or solvates thereof, wherein T is a radical of a ligand for a target protein of an influenza virus or a virus-infected cell; L1, L2, and L3are each, an independently selected linker; and 25 A1and A2are each, a radical of an independently selected hapten.

[0413] Embodiment A2 relates to the compound of Embodiment A1 wherein the target protein is a neuraminidase.

[0414] Embodiment A3 relates to the compound of Embodiment A1 wherein the ligand is a neuraminidase inhibitor. 30

[0415] Embodiment A4 relates to the compound of Embodiment A1 wherein the ligand is selected from sialic acid and analogs thereof.

[0416] Embodiment A5 relates to the compound of Embodiment A1 wherein the ligand is - 91 -70849-04 selected from zanamivir, peramivir, laninamivir, oseltamivir, and 2,3-dehydro-2-deoxy-n- acetylneuraminic acid, and analogs and derivatives of the foregoing.

[0417] Embodiment A6 relates to the compound of Embodiment A1 wherein the ligand is zanamivir, or analog or derivative thereof. 5

[0418] Embodiment A7 relates to the compound of Embodiment A1 wherein the ligand is peramivir, or an analog or derivative thereof.

[0419] Embodiment A8 relates to the compound of Embodiment A1 wherein the ligand is a compound of the formula:10 or an analog or derivative thereof.

[0420] Embodiment A9 relates to the compound of Embodiment A1 wherein the ligand is laninamivir, or an analog or derivative thereof.

[0421] Embodiment A10 relates to the compound of Embodiment A1 wherein the ligand is of the formula: 15or an analog or derivative thereof.

[0422] Embodiment A11 relates to the compound of Embodiment A1 wherein the ligand is oseltamivir, or an analog or derivative thereof.

[0423] Embodiment A12 relates to the compound of Embodiment A1 wherein the target 20 protein is a hemagglutinin.

[0424] Embodiment A13 relates to the compound of Embodiment A1 wherein the ligand is a hemagglutinin inhibitor.

[0425] Embodiment A14 relates to the compound of Embodiment A1 wherein the ligand is: - 92 -70849-04and analogs and derivatives thereof.

[0426] Embodiment A15 relates to the compound of Embodiment A1 wherein the ligand is umifenovir, arbidol, tert-butyl hydroquinone, flufirvitide 3 (VEDTKIDLWSYNAELL (SEQ 5 ID NO: 1)), cyclo(Ac-YWHKNKYVLTYSC)LFAAG-CONH2 (SEQ ID NO: 2), cyclo(Ac- YRWVWTSFFSEPYFVVC)G-CONH2 (SEQ ID NO: 3), cyclo(Ac- YLKIYWSKIHGLVSEWC)G-CONH2 (SEQ ID NO: 4), or cyclo(Ac- YVLFRWDHGTLATHWVC)G-CONH2(SEQ ID NO: 5).

[0427] Embodiment A16 relates to the compound of Embodiment A1 wherein the ligand is 10 not a folate.

[0428] Embodiment A17 relates to the compound of Embodiments A1-A16, wherein A1and A2 are the same hapten.

[0429] Embodiment A18 relates to the compound of Embodiments A1-A17, wherein A1 and A2 are different haptens. 15

[0430] Embodiment A19 relates to the compound of Embodiments A1-A18, wherein the hapten is selected from a rhamnose, a nitrophenyl, a nitrophenol, a nitroaniline, a dinitrophenyl (DNP), a dinitrophenol, a dinitroaniline, a trinitrophenyl (TNP), a trinitrophenol, a trinitroaniline, chloronitrophenyl, a chloronitrophenol, a chloronitroaniline, an iodonitrophenyl, an iodonitrophenol, an iodonitroaniline, a nitrotyrosine, an 20 hydroxynitrotyrosine, an aminonitrotyrosine, 4-hydroxy-3-nitrophenyl acetic acid, an ^- galactosyl moiety, a sulfated Gal, a phosphorylcholine, a bacterial antigen, and a viral antigen or A1 and A2 are each an independently selected radical of a rhamnose, ^-galactosyl moiety, dinitrobenzene, dinitroaniline, trinitrobenzene, and dinitroaniline.

[0431] Embodiment A20 relates to the compound of Embodiments A1-A19, wherein A1 25 and / or A2 is a radical of a dinitrophenyl (DNP), a dinitrophenol, or a dinitroaniline.

[0432] Embodiment A21 relates to the compound of Embodiments A1-A20, wherein A1 and / or A2 is a radical of a rhamnose, including L-rhamnose. - 93 -70849-04

[0433] Embodiment A22 relates to the compound of Embodiments A1-A21, wherein one of A1 and A2 is a radical of L-rhamnose; and the other of A1 and A2 is a radical of a dinitroaniline.

[0434] Embodiment A23 relates to the compound of Embodiments A1-A22, wherein the 5 hapten has an epitope that has an endogenous Ab, B, or T cell.

[0435] Embodiment A24 relates to the compound of Embodiments A1-A23, wherein the hapten is not FITC.

[0436] Embodiment A25 relates to the compound of Embodiments A1-A24, wherein L2and L3are attached to the same atom of L1. 10

[0437] Embodiment A26 relates to the compound of Embodiments A1-A25, wherein L2 and L3 are bound to the same atom on L1.

[0438] Embodiment A27 relates to the compound of Embodiments A1-A26, wherein L2and L3are bound to the same non-carbon atom on L1.

[0439] Embodiment A28 relates to the compound of Embodiments A1-A27, wherein L2and 15 L3are bound to the same nitrogen atom on L1.

[0440] Embodiment A29 relates to the compound of Embodiments A1-A28, wherein L2and L3are attached to different atoms of L1.

[0441] Embodiment A30 relates to the compound of Embodiments A1-A29, wherein one or more of L1, L2, and L3is a single divalent atom selected from N, O, P, and S, where N and P 20 are optionally substituted.

[0442] Embodiment A31 relates to the compound of Embodiments A1-A30, wherein one or more of L1, L2, and L3is a chain of atoms, where the length of each chain is independently selected and in the range of about 2 to about 60.

[0443] Embodiment A32 relates to the compound of Embodiments A1-A31, wherein one or25 more of L1, L2, and L3includes or also includes ethoxy, ethylamino, ethylene glycol, aza- ethylene glycol, (PEG)n, or aza-(PEG)n, or a combination thereof, where n is in the range from 2 to about 36.

[0444] Embodiment A33 relates to the compound of Embodiments A1-A32, wherein one or more of L1, L2, and L3includes or also includes (PEG)n, or aza-(PEG)n, or a combination 30 thereof, where n is 2-36.

[0445] Embodiment A34 relates to the compound of Embodiments A1-A33, wherein each of L1, L2, and L3includes or also includes ethoxy, ethylamino, ethylene glycol, aza-ethylene glycol, (PEG)n, or aza-(PEG)n, or a combination thereof, where n is 2-36. Embodiment A35 relates to the compound of Embodiments A1-A34, wherein one or more of - 94 -70849-04 L1, L2, and L3includes or also includes O-alkyl-O, N-alkyl-N, C(O)-alkyl-C(O), or NC(O)- alkyl-C(O)N, or a combination thereof.

[0446] Embodiment A36 relates to the compound of Embodiments A1-A35, wherein one or more of L1, L2, and L3includes or also includes O-alkyl-C(O), N-alkyl-C(O), O-alkyl-N- 5 alkyl-C(O), N-alkyl-O-alkyl-C(O), or C(O)alkyl-C(O), or a combination thereof.

[0447] Embodiment A37 relates to the compound of Embodiments A1-A36, wherein one or more of L1, L2, and L3includes or also includes O-alkyl-C(O)N-diyl, O-alkyl-O-alkyl- C(O)N-diyl, or N-alkyl-O-alkyl-O-alkyl-C(O)N-diyl.

[0448] Embodiment A38 relates to the compound of Embodiments A1-A37, wherein one or 10 more of L1, L2, and L3includes or also includes one or more amino acids.

[0449] Embodiment A39 relates to the compound of Embodiments A1-A38, wherein one or more of L1, L2, and L3includes or also includes one or more hydrophilic amino acids selected from Arg, Asn, Asp, Cys, Glu, Gln, His, Lys, Met, Orn, Ser, or Thr, including the naturally occurring L-enantiomers of each of the foregoing. 15

[0450] Embodiment A40 relates to the compound of Embodiments A1-A39, wherein one or more of L1, L2, and L3includes or also includes one or more hydrophilic amino acids selected from ^-NH2-Ala, Arg, Asn, Asp, Cys, Glu, Gln, His, Lys, Met, Orn, Ser, or Thr, including the naturally occurring L-enantiomers of each of the foregoing.

[0451] Embodiment A41 relates to the compound of Embodiments A1-A40, wherein one or 20 more of L1, L2, and L3includes or also includes one or more amino acids selected from glycine, serine, proline, ornithine, and lysine.

[0452] Embodiment A42 relates to the compound of Embodiments A1-A41, wherein one or more of L1, L2, and L3includes or also includes an ornithine or lysine, including L-ornithine and L-lysine. 25

[0453] Embodiment A43 relates to the compound of Embodiments A1-A42, wherein one or more of L1, L2, and L3includes or also includes a lysine, including L-lysine.

[0454] Embodiment A44 relates to the compound of Embodiments A1-A43, wherein one or more of L1, L2, and L3includes or also includes a proline, including L-proline.

[0455] Embodiment A45 relates to the compound of Embodiments A1-A44, wherein one or 30 more of L1, L2, and L3includes or also includes a (Pro)n, including (L-Pro)n, where n is 1-6.

[0456] Embodiment A46 relates to the compound of Embodiments A1-A45, wherein one or more of L1, L2, and L3includes or also includes a (Pro)3, including (L-Pro)3.

[0457] Embodiment A47 relates to the compound of Embodiments A1-A46, wherein one or more of L1, L2, and L3includes or also includes a (Pro)3-Lys, including (L-Pro)3-(L-Lys). - 95 -70849-04

[0458] Embodiment A48 relates to the compound of Embodiments A1-A47, wherein one or more of L1, L2, and L3includes or also includes a (Pro)6, including (L-Pro)6.

[0459] Embodiment A50 relates to the compound of Embodiments A1-A48, wherein one or more of L1, L2, and L3includes or also includes a (Pro)6-Lys, including (L-Pro)6-(L-Lys). 5

[0460] Embodiment A51 relates to the compound of Embodiments A1-A49, wherein one or more of L1, L2, and L3includes or also includes glycine and serine, including L-serine.

[0461] Embodiment A52 relates to the compound of Embodiments A1-A50, wherein one or more of L1, L2, and L3includes or also includes (Gly-Ser)n, including [Gly-(L-Ser)]n, where n is 1-3. 10

[0462] Embodiment A53 relates to the compound of Embodiments A1-A51, wherein one or more of L1, L2, and L3includes or also includes (Gly-Ser)2, including [Gly-(L-Ser)]2.

[0463] Embodiment A54 relates to the compound of Embodiments A1-A52, wherein one or more of L1, L2, and L3includes or also includes (Gly-Ser)2-Lys, including [Gly-(L-Ser)]2-(L- Lys). 15

[0464] Embodiment A55 relates to the compound of Embodiments A1-A53, wherein one or more of L1, L2, and L3includes or also includes (Gly-Ser)3, including [Gly-(L-Ser)]3.

[0465] Embodiment A56 relates to the compound of Embodiments A1-A54, wherein one or more of L1, L2, and L3includes or also includes (Gly-Ser)3-Lys, including [Gly-(L-Ser)]3-(L- Lys). 20

[0466] Embodiment A57 relates to the compound of Embodiments A1-A55, wherein one or more of L1, L2, and L3includes or also includes a C(O), C(O)O, C(O)NH, OC(O)NH, or NHC(O)NH group.

[0467] Embodiment A58 relates to the compound of Embodiments A1-A56, wherein one or more of L1, L2, and L3includes or also includes 1,2,3-triazol-1,4-diyl, or a combination 25 thereof.

[0468] Embodiment A59 relates to the compound of Embodiments A1-A57, wherein one or more of L1, L2, and L3includes or also includes a maleimid-diyl or thiomaleimid-N,S-diyl.

[0469] Embodiment A60 relates to the compound of Embodiments A1-A58, wherein L2and / or L3are hydrophilic. 30

[0470] Embodiment A61 relates to the compound of Embodiments A1-A59, wherein L1includes a region that is capable of forming an ^-helical conformation.

[0471] Embodiment A62 relates to the compound of Embodiments A1-A60, wherein the extended conformation of L2and / or L3is at least 8 Å, 9 Å, 10 Å, 11 Å, 12 Å, 13 Å, 14 Å, 15 Å, 20 Å, 25 Å, 30 Å, 35 Å, or 40 Å, in length. - 96 -70849-04

[0472] Embodiment A63 relates to the compound of Embodiments A1-A61, wherein L2and / or L3includes or also includes (PEG)nor aza-(PEG)n, where n is in the range from about 3 to about 36, from about 4 to about 36, from about 5 to about 36, from about 6 to about 36, or from about 7 to about 36. 5

[0473] Embodiment A64 relates to the compound of Embodiments A1-A62, wherein L2and / or L3includes or also includes one or more divalent cycloalkyl, including adamantyl, heterocyclyl, including maleimidyl, aryl, heteroaryl including triazolyl, stilbene, oligoproline, or oligopiperidine groups.

[0474] Embodiment A65 relates to the compound of Embodiments A1-A63, wherein the 10 extended conformation of T-L1is at least 5 Å, 6 Å, 7 Å, 8 Å, 9 Å, 10 Å, 11 Å, or 12 Å in length.

[0475] Embodiment A66 relates to the compound of Embodiments A1-A64, wherein L1includes or also includes (PEG)nor aza-(PEG)n, where n is in the range from about 3 to about 36, from about 4 to about 36, from about 5 to about 36, or from about 6 to about 36. 15

[0476] Embodiment A67 relates to the compound of Embodiments A1-A65, wherein L1does not include L-lysine.

[0477] Embodiment A68 relates to the compound of Embodiments A1-A66, wherein L1does not include DBCO.

[0478] Embodiment A69 relates to the compound of Embodiments A1-A67, wherein the 20 conjugate is not:where L1, L2, and L3are each, independently linkers; or:- 97 -70849-04 or.

[0479] Embodiment A70 relates to a compound of any formula shown in FIG.7, or a 5 pharmaceutically acceptable salt or solvate thereof.

[0480] Embodiment A71 relates to a compound of the formula:or a pharmaceutically acceptable salt or solvate thereof.

[0481] Embodiment A72 relates to a compound of the formula: 10or a pharmaceutically acceptable salt or solvate thereof.

[0482] Embodiment A73 relates to a compound of the formula:or a pharmaceutically acceptable salt or solvate thereof. 15

[0483] Embodiment A74 relates to a compound of the formula: - 98 -70849-04or a pharmaceutically acceptable salt or solvate thereof.

[0484] Embodiment A75 relates to a pharmaceutical composition comprising (i) a conjugate of the formula: 5, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0485] Embodiment A76 relates to a pharmaceutical composition for use in treating an 10 influenza infection, the composition comprising (i) a therapeutically effective amount of a conjugate of the formula: A1T LA2, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a 15 linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0486] Embodiment A77 relates to a unit dose or unit dosage form in single or divided form, the unit dose or unit dosage comprising (i) a therapeutically effective amount of a conjugate of the formula:, 20 and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0487] Embodiment A78 relates to a method for treating an influenza infection in a host animal, the method comprising the step of administering to the host animal a composition 25 comprising (i) a therapeutically effective amount of a conjugate of the formula: - 99 -70849-04 , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant. 5

[0488] Embodiment A79 relates to the use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising (i) a therapeutically effective amount of a conjugate of the formula: , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target 10 protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0489] Embodiment A80 relates to a pharmaceutical composition, unit dose, or unit dosage form comprising (i) a conjugate of the formula:, 15 and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

[0490] Embodiment A81 relates to the pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A75, A77, or A80, wherein T is a radical of the 20 formula:.

[0491] Embodiment A82 relates to the pharmaceutical composition, unit dose, or unit dosage form of Embodiment A81, wherein T is a radical of the formula: - 100 -70849-04.

[0492] Embodiment A83 relates to the pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A75, A77, A80 or A81, wherein L is L1, L2, and L3, comprise a group of the formula: 5.

[0493] Embodiment A84 relates to pharmaceutical composition, unit dose, or unit dosage form comprising (i) a compound of the formula:, 10 and (ii) a non-ionic surfactant.

[0494] Embodiment A85 relates to a pharmaceutical composition, unit dose, or unit dosage form comprising Compound 24 and a non-ionic surfactant.

[0495] Embodiment A86 relates to the pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A84 or A85, wherein the non-ionic surfactant is n- 15 dodecyl ^-D-maltoside.

[0496] Embodiment A87 relates to the pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A75, A77, A80, A81, A84 or A85, further comprising a carrier.

[0497] Embodiment A88 relates to the pharmaceutical composition, unit dose, or unit 20 dosage form of Embodiment A87 wherein the carrier is phosphate-buffered saline. - 101 -70849-04

[0498] Embodiment A89 relates to a method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A75, A76, A77, and A80-A88. 5

[0499] Embodiment A90 relates to the use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of any one of Embodiments A75, A76, A77, and A80-A88. - 102 -

Claims

70849-04 WHAT IS CLAIMED IS: . A pharmaceutical composition comprising (i) a conjugate of the formula:, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1and A2are each, independently, a hapten; and (ii) a non-ionic surfactant. . A pharmaceutical composition for use in treating an influenza infection, the composition comprising (i) a therapeutically effective amount of a conjugate of the formula: , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant. . A unit dose or unit dosage form in single or divided form, the unit dose or unit dosage comprising (i) a therapeutically effective amount of a conjugate of the formula: , and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

4. A method for treating an influenza infection in a host animal, the method comprising the step of administering to the host animal a composition comprising (i) a therapeutically effective amount of a conjugate of the formula:, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, - 103 -70849-04 independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

5. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising (i) a therapeutically effective amount of a conjugate of the formula:, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

6. A pharmaceutical composition, unit dose, or unit dosage form comprising (i) a conjugate of the formula:, and pharmaceutically acceptable salts thereof, wherein T is a targeting ligand for a target protein on the surface of a virus or a virus-infected cell; L1-L3are each, independently, a linker; and A1 and A2 are each, independently, a hapten; and (ii) a non-ionic surfactant.

7. The pharmaceutical composition, unit dose, or unit dosage form of any one of claims 1, 3, or 6, wherein T is a radical of the formula:.

8. The pharmaceutical composition, unit dose, or unit dosage form of claim 7, wherein T is a radical of the formula: - 104 -70849-04.

9. The pharmaceutical composition, unit dose, or unit dosage form of any one of claims 1, 3, or 6, wherein L is L1, L2, and L3, comprise a group of the formula:.

10. The pharmaceutical composition, unit dose, or unit dosage form of claim 7, wherein L is L1, L2, and L3, comprise a group of the formula:.

11. A pharmaceutical composition, unit dose, or unit dosage form comprising (i) a compound of the formula:, and (ii) a non-ionic surfactant.

12. A pharmaceutical composition, unit dose, or unit dosage form comprising Compound 24 and a non-ionic surfactant. - 105 -70849-04 13. The pharmaceutical composition, unit dose, or unit dosage form of any one of claims 11 or 12, wherein the non-ionic surfactant is n-dodecyl ^-D-maltoside.

14. The pharmaceutical composition, unit dose, or unit dosage form of any one of claims 1, 3, 6, 11, or 12, further comprising a carrier.

15. The pharmaceutical composition, unit dose, or unit dosage form of claim 7, further comprising a carrier.

16. The pharmaceutical composition, unit dose, or unit dosage form of claim 14 wherein the carrier is phosphate-buffered saline.

17. The pharmaceutical composition, unit dose, or unit dosage form of claim 15 wherein the carrier is phosphate-buffered saline.

18. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of any one of claims 1, 2, 3, 6, 11, or 12.

19. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of any one of claims 1, 2, 3, 6, 11, or 12.

20. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 7.

21. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 7.

22. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 8.

23. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 8.

24. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 9.

25. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 9. - 106 -70849-04 26. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 10.

27. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 10.

28. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 13.

29. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 13.

30. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 14.

31. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 14.

32. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 15.

33. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 15.

34. A method of treating influenza infection in a host animal, the method comprising the step of administering to the host animal a pharmaceutical composition, unit dose, or unit dosage form of claim 16.

35. Use of a composition in the manufacture of a medicament for treating an influenza infection, the composition comprising a pharmaceutical composition, unit dose, or unit dosage form of claim 16. - 107 -

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