Hydrogel pharmaceutical compositions and their methods of use for treatment of cancer

Abstract

Described herein are pharmaceutical compositions and methods of their use for the treatment of cancer. The pharmaceutical compositions comprise a first anticancer drug formulated as nanoparticles or microparticles, the nanoparticles or microparticles uniformly dispersed in the injectable hydrogel polymer matrix formulation. This matrix comprises an anionic polymer and an inverse thermal gelling polymer, which transitions from a liquid to a gel state at specific temperatures and demonstrates shear-thinning properties to facilitate injection and gel reformation. The pharmaceutical compositions are administered intratumorally into solid tumors to treat cancer in a subject requiring such treatment. The method may additionally include systemic administration of a therapeutically effective amount of a second anticancer drug.

Description

HYDROGEL PHARMACEUTICAL COMPOSITIONS AND THEIR METHODS OF USE FOR TREATMENT OF CANCER CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from United States patent application 63 / 686,840 filed on August 25, 2024, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The pharmaceutical compositions and methods described herein relate to the field of cancer treatment and, in particular, treatment of solid tumors. BACKGROUND OF THE ART

[0003] Cancer remains one of the leading causes of morbidity and mortality worldwide. Conventional treatment modalities include surgery, radiation, chemotherapy, and immunotherapy. Among these, chemotherapy and immunotherapy have been extensively used and researched for their effectiveness in treating various types of cancers. However, each of these treatments has limitations that affect their overall efficacy and patient outcomes.

[0004] Chemotherapy involves the use of drugs to kill or inhibit the growth of cancer cells. Despite its widespread use, chemotherapy is associated with several disadvantages, including systemic toxicity as chemotherapeutic agents often cause significant side effects due to their non- specific targeting of rapidly dividing cells, affecting both cancerous and healthy tissues. Another disadvantage is the inability of chemotherapeutic agents to adequately penetrate certain solid tumors which can result in suboptimal drug concentrations at the target site, leading to reduced efficacy.

[0005] Immunotherapy, particularly the use of immune checkpoint inhibitors (ICIs), has emerged as a promising cancer treatment by harnessing the body's immune system to target and destroy cancer cells. ICIs block proteins that inhibit the immune response, allowing T-cells to attack cancer cells more effectively. However, this approach also has its limitations. Blocking ICIs can lead to an overactive immune response, causing inflammation and autoimmune-like side effects. Not all patients respond to ICIs, and the reasons for this variability are not fully understood.

[0006] Given the challenges associated with conventional cancer therapy, there is a need for innovative methods and delivery systems that can improve the therapeutic index of anticancer drugs. BRIEF SUMMARY

[0007] Certain embodiments provide for a method of treating cancer comprising administering to solid tumors in a subject in need thereof a therapeutically effective amount of the pharmaceutical compositions described herein comprising a first anticancer drug formulated as nanoparticles or microparticles dispersed in a hydrogel polymer matrix formulation comprising from 0.1% – 3.0% (wt / wt) of an anionic gelling polymer and from 0.1% – 3.0% (wt / wt) of an inverse thermal gelling polymer, wherein the administration is performed intratumorally.

[0008] Certain embodiments provide for a method of treating cancer comprising administering to a solid tumor in a subject in need thereof a therapeutically effective amount of the pharmaceutical compositions described herein comprising a first anticancer drug formulated as nanoparticles or microparticles dispersed in a hydrogel polymer matrix formulation comprising from 0.1% – 3.0% (wt / wt) hyaluronan and from 0.1% – 0.3% (wt / wt) methylcellulose, wherein the administration is performed intratumorally.

[0009] In some embodiments, the hydrogel polymer matrix formulation consists or consists essentially of the anionic gelling polymer (e.g. hyaluronan) and the inverse thermal gelling polymer (e.g. methycellulose), with the remainder being water and or biocompatible salts.

[0010] Some embodiments provide for a method of treating cancer comprising administering intratumorally in a patient a therapeutically effective amount of at least two or more pharmaceutical compositions, each composition comprising a distinct first anticancer drug, formulated as nanoparticles or microparticles, dispersed in a hydrogel polymer matrix formulation described herein.

[0011] As used herein, a “first anticancer” drug is used to refer to an anticancer drug delivered in a hydrogel polymer matrix as described herein. In certain embodiments, the nanoparticle or microparticle formulations described herein comprise only one first anticancer drug, while in some embodiments, more than one first anticancer drug may be administered i.e. more than one anticancer drug may be administered in a hydrogel polymer matrix as described herein (in someembodiments, in a single pharmaceutical composition, while in other embodiments, in separately administered pharmaceutical compositions as provided herein) .

[0012] In certain embodiments, the nanoparticle or microparticles formulations described herein consist of only one first anticancer drug.

[0013] In certain embodiments, the method of treating cancer in a subject in need thereof by the intratumoral administration of a therapeutically effective amount of the pharmaceutical compositions described herein may further comprise systemic administration of a therapeutically effective amount of a second anticancer drug.

[0014] In certain embodiments, the first anticancer drug may be a chemotherapeutic. In certain embodiments, the chemotherapeutic is docetaxel.

[0015] In certain embodiments, the second anticancer may be an ICI. In certain embodiments, the ICI may be an anti-CTLA-4 monoclonal antibody.

[0016] In certain embodiments, the pharmaceutical composition is a solid at room temperature, experiences shear thinning when subjected to applied pressure (e.g., during injection), and reverts to a solid gel once the pressure is removed.

[0017] In certain embodiments, the pharmaceutical compositions described herein may be administered using a delivery device selected from the group consisting of syringes, cannulas, and microinjectors. In certain embodiments, the delivery device is preferably a cannula.

[0018] In certain embodiments, a therapeutically effective amount of the pharmaceutical compositions described herein comprising one first anticancer drug and a therapeutically effective amount of at least one second anticancer drug may be administered simultaneously, repetitively, in sequence, or in any combination thereof.

[0019] In certain embodiments, the first anticancer drug is formulated as nanoparticles, which are dispersed in an injectable hydrogel polymer matrix formulation, said hydrogel formulation comprising an anionic gelling polymer and an inverse thermal gelling polymer.

[0020] In certain embodiments, the amounts of the inverse thermal gelling polymer and the anionic gelling polymer comprising the hydrogel polymer matrix formulation are selected to obtaina solid gel prior to injection, undergo shear thinning upon injection, and return to a solid gel after injection.

[0021] In certain embodiments, the hydrogel polymer matrix formulation provides for a sustained release of the first anticancer drug.

[0022] In certain embodiments, the hydrogel polymer matrix formulation provides for a zero- order sustained release of the first anticancer drug.

[0023] In certain embodiments, the ratio of the anionic gelling polymer to the inverse thermal gelling polymer may be from 1:1 (wt / wt) – 1:20 (wt / wt). In certain embodiments, the ratio of the anionic gelling polymer to inverse thermal gelling polymer is from 1:1 (wt / wt).

[0024] In certain embodiments, the hydrogel polymer matrix formulation comprises 0.1% – 3.0% (wt / wt) anionic gelling polymer and 0.1% – 3.0% (wt / wt) inverse thermal gelling polymer.

[0025] In certain embodiments, the combined total amount of the inverse thermal gelling polymer and anionic gelling polymer in the hydrogel polymer matrix formulation comprises between 0.2% and 6% (wt / wt).

[0026] In certain embodiments, the anionic gelling polymer is hyaluronan and the inverse thermal gelling polymer is methylcellulose.

[0027] In certain embodiments, the ratio of the hyaluronan to the methylcellulose may be from 1:1 (wt / wt) – 1:20 (wt / wt). In certain embodiments, the ratio of the hyaluronan to methylcellulose is from 1:1 (wt / wt).

[0028] In certain embodiments, the hydrogel polymer matrix formulation comprises 0.1% – 3.0% (wt / wt) hyaluronan and 0.1% – 3.0% (wt / wt) methylcellulose.

[0029] In certain embodiments, the combined total amount of the hyaluronan and methylcellulose in the hydrogel polymer matrix formulation comprises between 0.2 and 6.0% (wt / wt).

[0030] In certain embodiments, the nanoparticles or microparticles comprise a carrier comprising a biodegradable polymer wherein the carrier encapsulates the first anticancer drug.

[0031] In certain embodiments, it is preferrable that the pharmaceutical composition comprises 10% (wt / wt) of the biodegradable polymer.

[0032] In certain embodiments, the biodegradable polymer is Poly(lactic-co-glycolic acid)(PLGA). In certain embodiments, the nanoparticles have an average diameter of from 150 nm – 250 nm.

[0033] In certain embodiments, the first anticancer drug may be a taxane. In certain embodiments, the first anticancer drug is preferably docetaxel.

[0034] In certain embodiments, the at least one second-anticancer drug may be an ICI. In certain embodiments, the at least one second anticancer drug is preferably an anti-CTLA4 monoclonal antibody.

[0035] In certain embodiments, a therapeutically effective amount of the pharmaceutical compositions described herein may be used for the intratumoral administration of the compositions in solid tumors for the treatment of cancer in a subject in need thereof.

[0036] In certain embodiments, the pharmaceutical compositions described herein are designed for direct intratumoral injection in solid tumors, providing localized delivery and reducing systemic exposure of the chemotherapeutic agent in a subject in need thereof.

[0037] Certain embodiments contemplate kits comprising one or more parts.

[0038] The above summary of the embodiments described herein is not intended to describe each disclosed embodiment or every implementation of the pharmaceutical compositions described herein. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the description, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIGURE 1, comprising Figures 1A, 1B, and 1C, presents a series of graphs showing the effects of the pharmaceutical composition according to an embodiment comprising docetaxel as the first anticancer drug, administered intratumorally, compared to the systemic administration of docetaxel solution in mice exposed to a lung cancer cell line per Example 4. Figure 1A showsthe impact on tumor volume, Figure 1B shows the probability of survival, and Figure 1C shows changes in body weight.

[0040] FIGURE 2, comprising Figures 2A, 2B, and 2C, presents a series of graphs showing the effects of the intratumoral administration of a solution of docetaxel as the first anticancer drug compared to the systemic administration of a solution of docetaxel in mice exposed to a lung cancer cell line per Example 4. Figure 2A shows the impact on tumor volume, Figure 2B shows the probability of survival, and Figure 2C shows changes in body weight.

[0041] FIGURE 3, comprising Figures 3A, 3B, and 3C, presents a series of graphs showing the effects of the pharmaceutical composition according to an embodiment comprising docetaxel as the first anticancer drug, administered intratumorally, in combination with the systemic administration of an anti-CTLA4 monoclonal antibody as the second anticancer drug in mice exposed to a colorectal cancer cell line per Example 4. These results are compared to the systemic administration of the anti-CTLA4 antibody alone and the intratumoral administration of the pharmaceutical composition comprising docetaxel alone. Figure 3A shows the impact of each therapy on tumor volume, Figure 3B shows the impact of each therapy on the probability of survival, and Figure 3C shows the impact of each therapy on changes in body weight.

[0042] FIGURE 4, comprising Figures 4A, 4B, and 4C, presents a series of graphs showing the effects of the pharmaceutical composition according to an embodiment comprising docetaxel as the first anti-cancer drug, administered intratumorally, in combination with the systemic administration of an anti-CTLA4 monoclonal antibody as the second anticancer drug of mice exposed to a colorectal cancer cell line per Example 4. These results are compared to the systemic administration of the anti-CTLA4 monoclonal antibody alone and the systemic administration of a solution of docetaxel in combination with the systemic administration of the anti-CTLA4 monoclonal antibody. Figure 4A shows the impact of each therapy on tumor volume, Figure 4B shows the impact of each therapy on the probability of survival, and Figure 4C shows the impact of each therapy on changes in body weight. DETAILED DESCRIPTION

[0043] The following detailed description is provided to aid those skilled in the art in practicing the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0044] All features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

[0045] The numerical values specified throughout this disclosure including the claims, are stated as approximations as though the numerical values are preceded by the word “about” unless expressly stated otherwise. Similarly, where a range of numeric values are specified, the minimum and maximum values of the range as well as all values within the range are stated as approximations as though preceded by the word “about” unless expressly stated otherwise. In this manner, the term “about”, “approximately”, and “comparable to” when used in reference to a particular recited value, means there can be an acceptable variation range, as determined by one of ordinary skill in the art to which this disclosure pertains. For example, in some embodiments, the terms "about," “approximately,” and “comparable to” may encompass a range of values within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less of the referred value. Also, the disclosure of ranges is intended as a continuous range including every value between the minimum and maximum values recited as well as any ranges that can be formed by such values. Also, disclosed herein are all ratios (and ranges of any such ratios) that can be formed by dividing a recited numeric value into any other recited numeric value. Accordingly, the skilled person will appreciate that many such ratios, ranges, and ranges of ratios can be unambiguously derived from the numerical values presented herein and, in all instances, such ratios, ranges, and ranges of ratios represent various embodiments of the present invention.

[0046] The term “and / or” means one or all the listed elements or a combination of any two or more of the listed elements.

[0047] As used herein, the term “treatment”, “treating”, “treat” or the like refers to an approach for obtaining beneficial or desired results, including clinical results. Beneficial or desired clinical results may include, but are not limited to, alleviation or amelioration of one or more symptoms or conditions, diminishment of extent of disease, stabilized (i.e. not worsening) state of disease, preventing spread of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. “Treatment” can also mean prolonging survival as compared to expected survival if not receiving treatment. As is recognized by the skilled person, the use of therapeutically effective amounts ofthe pharmaceutical compositions described herein can reduce the severity of a disease or physiological disorder but need not abolish every manifestation of a given disease or physiological disorder to be regarded as a useful therapeutic agent. Thus, “treatment” with the pharmaceutical compositions described need not effect a complete cure, or eradicate every symptom or manifestation of a disease, to constitute a viable therapy.

[0048] As used herein “encapsulating” means that the anticancer drug is partially or completely covered by a carrier layer or is distributed within the carrier forming the nanoparticles or microparticles.

[0049] As used herein, “therapeutically effective amount” refers to an amount effective, at dosages and for a particular period of time necessary, to achieve the desired therapeutic result. A therapeutically effective amount of the first and / or second anticancer drug (e.g., a small molecule anticancer drug and / or a biologic anticancer drug) may vary according to factors such as the disease state, age, sex, and weight of the subject, and the ability of said drugs to elicit a desired response in the individual. A therapeutically effective amount is also one in which any toxic or detrimental effects of said drugs are outweighed by the therapeutically beneficial effects.

[0050] The terms "chemotherapeutic" and “anticancer drug” are used interchangeably and as used herein broadly refers to any drug used to treat cancer.

[0051] The words “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0052] As used herein, “subject” or “patient” are used interchangeably and may be a human, domestic livestock, or a companion animal. In certain embodiments, the subject or patient is a human. A human subject or patient can be a pediatric, adult, or a geriatric subject, and can be of any gender.

[0053] Unless expressly stated otherwise, the “pharmaceutical composition(s)” described herein is a composite of a nanoparticle or microparticle formulation comprising a first anticancer drug dispersed in an injectable hydrogel polymer matrix formulation. Preferably, the nanoparticles or microparticles comprise only one anticancer drug.

[0054] As used herein, “microparticles” and “nanoparticles” refer to particles between 0.1 and 100 µm and between 1 to 100 nm in diameter respectively.

[0055] Localized administration of an anticancer drug, such as through intratumoral delivery using a suitable pharmaceutical composition, offers significant advantages over systemic delivery, particularly for treating “cold” tumors that are difficult to manage by conventional means or remove surgically. This targeted approach allows for higher local drug concentrations at the tumor site, maximizing therapeutic effects while minimizing systemic toxicity and side effects. The pharmaceutical composition(s) provided herein may protect the anticancer drug from degradation and reduce off-target exposure, further enhancing its safety profile. Additionally, combination treatments, which include additional anticancer agents, provide a more robust and safer therapeutic option, significantly improving outcomes for patients with challenging tumors. There remains a continuing need for advanced cancer treatment methods utilizing innovative pharmaceutical compositions that can deliver anticancer drugs directly to the target tumor site with precision, offering superior patient outcomes compared to conventional treatments by increasing efficacy and minimizing systemic exposure.

[0056] It has been unexpectedly found that intratumoral administration of therapeutically effective doses of the pharmaceutical compositions described herein leads to better outcomes in cancer-treated subjects than the same anticancer drug administered intratumorally as a solution (i.e., without a hydrogel matrix). Furthermore, combining intratumoral administration of these pharmaceutical compositions comprising a first anticancer drug with systemic administration of a second anticancer drug results in improved outcomes compared to the systemic administration of either the first or second anticancer drug alone. Additionally, an improved safety profile is observed when therapeutically effective doses of the pharmaceutical composition comprising the first anticancer drug is administered intratumorally alongside systemic administration of a second anticancer drug, as opposed to the systemic administration of both the first and second anticancer drugs.

[0057] The pharmaceutical compositions utilized in the methods described herein comprise injectable hydrogel polymer matrix formulations and an appropriately formulated first anticancer drug, wherein the appropriately formulated first anticancer drug is dispersed in the hydrogel polymer matrix. This approach provides significant benefits over the systemic delivery of the same first anticancer drug by achieving higher local drug concentrations at the tumor site, thereby enhancing therapeutic effects and minimizing systemic toxicity and side effects. These hydrogelsprotect the first anticancer drug from degradation and may be engineered to enable sustained release of the first anticancer drug, reducing the frequency of administration and minimizing off- target effects, thus improving the therapy's safety profile. Additionally, a suitable second anticancer drug may be administered systemically in combination with the localized targeted administration of the hydrogel comprising the first anticancer drug. This integrated approach for treating cancer addresses the limitations of single-agent therapies by offering a more effective and safer cancer treatment, combining the localized delivery of a first anticancer drug with the potent effects of a second anticancer drug, ultimately improving patient outcomes.

[0058] Injectable hydrogel polymer matrix formulations for use in the methods described herein have been described in for example, US patent nos. 7,767,656; and 9,205,046; the contents of which are incorporated herein by reference in their entirety.

[0059] Briefly, the injectable hydrogel formulation comprises a polymer matrix, the polymer matrix comprising an anionic gelling polymer and an inverse thermal gelling polymer, wherein the anionic gelling polymer possesses shear thinning properties that facilitate the return of the hydrogel polymer matrix to its original viscosity and solid gel state after shearing faster than the inverse thermal gelling polymer alone.

[0060] In certain embodiments, the amounts of the inverse thermal gelling polymer and the anionic gelling polymer comprising the injectable hydrogel may be selected to obtain a sustained release polymer matrix comprising a solid gel prior to injection, undergoing shear thinning upon injection, and returning to a solid gel after injection.

[0061] In certain embodiments, the amounts of the inverse thermal gelling polymer and the anionic gelling polymer comprising the injectable hydrogel may be selected to obtain a sustained release zero-order polymer matrix comprising a solid gel prior to injection, undergoing shear thinning upon injection, and returning to a solid gel after injection.

[0062] In certain embodiments, the ratio of the anionic gelling polymer to the inverse thermal gelling polymer may be from 1:1 (wt / wt) to 1:20 (wt / wt). In certain embodiments, the ratio of the anionic gelling polymer to the inverse thermal gelling polymer may be from1:1 (wt / wt).

[0063] In certain embodiments, the hydrogel polymer matrix formulation comprises 0.1% – 3.0% (wt / wt) anionic gelling polymer and 0.1% – 3.0% (wt / wt) inverse thermal gelling polymer. Incertain embodiments, the hydrogel polymer matrix formulation comprises 1% (wt / wt) anionic gelling polymer and 1% (wt / wt) inverse thermal gelling polymer.

[0064] In certain embodiments, the combined total amount of the inverse thermal gelling polymer and anionic gelling polymer in the hydrogel polymer matrix formulation comprises between 0.2% and 6.0% (wt / wt). In certain embodiments, the combined total amount of the inverse thermal gelling polymer and anionic gelling polymer in the hydrogel polymer matrix formulation may be 2% (wt / wt).

[0065] In certain embodiments, the anionic gelling polymer may be selected from hyluronan (HA), derivatives of hyluronan, alginate, derivatives of alginate, carboxymethyl cellulose (CMC), carboxyethyl cellulose (CEC), derivatives of hydroxypropyl cellulose (HPC), derivatives of hydroxypropyl methyl cellulose (HPMC), hydroxypropyl methyl cellulose phthalate (HPMCP), sodium carboxymethyl cellulose (Na-CMC) phosphorylated cellulose, sulfated cellulose, acrylates, C10-30 alkyl acrylate crosspolymer, carbomer, polyacrylic acid (PAA), poly(methacryclic acid) and mixtures thereof. It will be apparent to the skilled artisan that HPC and HPMC are not inherently anionic but can be chemically modified to introduce anionic groups, such as carboxyl or sulfonate groups, which would make them anionic.

[0066] In certain embodiments, the molecular weight of the anionic gelling polymer may be between about 100,000 Da and about 7,000,000 Da.

[0067] In certain embodiments, hyaluronan is the preferred anionic gelling polymer. In certain embodiments, the molecular weight of the hyaluronan is 1,520,000 Da.

[0068] In certain embodiments, the inverse thermal gelling polymer may be selected from methylcellulose, a chitosan and β-glycerophosphate solution, collagen, tri-block copolymer of poly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly(ethylene glycol), tri-block copolymer of poly(propylene glycol)-poly(ethylene glycol)-poly (propylene glycol), poly(N-isopropyl acrylamide), agarose, copolymers of poly-N-isopropylacrylamide, polysaccharides and mixtures thereof.

[0069] In certain embodiments, the molecular weight of the inverse thermal gelling polymer may be between about 2,000 Da and about 1,000,000 Da.

[0070] In certain embodiments, the preferred inverse thermal gelling polymer is methylcellulose. In certain embodiments, the methylcellulose has a viscosity greater than 400 cP. In certain embodiments, the methylcellulose has a viscosity of 2800 cP.

[0071] In certain embodiments, the ratio of the hyaluronan to the methylcellulose may be from 1:1 (wt / wt) to 1:20 (wt / wt). In certain embodiments, the ratio of the hyaluronan to methylcellulose may be from 1:1 (wt / wt).

[0072] In certain embodiments, the hydrogel polymer matrix formulation comprises 0.1% – 3.0% (wt / wt) hyaluronan and 0.1% – 3.0% (wt / wt) methylcellulose. In certain embodiments, the hydrogel polymer matrix formulation comprises 1% (wt / wt) hyaluronan and 1% (wt / wt) methylcellulose.

[0073] In certain embodiments, the combined total amount of the hyaluronan and methylcellulose in the hydrogel polymer matrix formulation comprises between 0.2% and 6% (wt / wt). In certain embodiments, the combined total amount of hyaluronan and methylcellulose in the hydrogel polymer matrix formulation may be 2% (wt / wt).

[0074] In certain embodiments, the hydrogel polymer matrix formulation may be engineered to provide a sustained release of the nanoparticles or microparticles comprising the first anticancer drug dispersed therein by changing the ratio of the anionic polymer to inverse thermal gelling polymer over a period of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 days after intratumoral administration. In certain other embodiments, the hydrogel polymer matrix formulation may be engineered to provide a sustained release zero-order of the first anticancer drug dispersed therein over a period of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 days after intratumoral administration.

[0075] Methods of manufacturing the injectable hydrogel polymer matrix formulations described herein are described for example in US patent 9,205,046 which is incorporated herein by reference in its entirety and in Example 1 herein.

[0076] In certain embodiments, the first anticancer drug may be formulated as nanoparticles or microparticles which are uniformly dispersed in the hydrogel polymer matrix to form the pharmaceutical compositions for use in methods for treating cancer described herein. The nanoparticles or microparticles may comprise a carrier comprising a biocompatible polymer or lipid which encapsulates the first anticancer drug payload. In certain embodiments, the biocompatible polymer may be biodegradable or non-biodegradable. In some embodiments, thepharmaceutical composition comprises 1% – 50% (wt / wt) of the biocompatible polymer. In some embodiments, the pharmaceutical composition comprises 1% – 20% (wt / wt) of the biocompatible polymer. In certain embodiments, the pharmaceutical composition comprises 1% –10% (wt / wt) of the biocompatible polymer. In certain embodiments, it is preferrable that the pharmaceutical composition comprises 10% (wt / wt) of the biocompatible polymer. In certain embodiments, the use of a biodegradable polymer is preferred.

[0077] Suitable biodegradable polymers for producing the nanoparticles or microparticles include, but are not limited to polyesters such as polylactide, polyglycolide, copolymers of lactide and glycolide, polyhydroxybutyrate, polycaprolactone (PCL), copolymers of lactic acid and lactone, copolymers of lactic acid and PEG, copolymers of α-hydroxy acids and α-amino acids (polydepsipeptides), polyanhydrides, polyorthoesters, polyphosphazenes, copolymers of hydroxybutyrate and hydroxyvalerate, poly ethylene carbonate), copoly(ethylene carbonate), polyethyleneterephthalate or mixtures of these polymers. Examples of resorbable / biodegradable polymers are lactide homopolymers poly(L-lactide), poly(D,L-lactide), and copolymers of lactide and glycolide such as 50:50 poly(lactic-co-glycolic acid) (PLGA). While polyethylene glycol (PEG) is the preferred water soluble polymer for mixing with the biodegradable polymer, other suitable water soluble polymers include poly(oxyethylene oxide)(PEO), poly(oxyethylene)- poly(oxypropylene) [PEO-PPO] block copolymers such as tri-block PEO-PPO-PEO copolymers (Poloxamers, Pluronics) and tetra-functional block copolymers derived from the sequential addition of propylene oxide and ethylene oxide to ethylene diamine (Poloxamines, Tetronics), copolymers of PEG with poly(lactic acid), oligomers of poly(lactic acid), lactides, copolymers of PEG and amino acids, conjugates of PEG with polysaccharides for example a conjugate produced from 40000 MW dextran and polyoxyethylene-glycol monomethyl ether and others as described by Duval et al. in Carbohydrate Polymers, 15, (1991), 233-242, conjugates of PEG with proteins such as those described by Nucci et al., in Advances in Drug Delivery Review, 6, (1981), 113-151, or with collagen as described by Rhee et al in Poly(ethylene glycol) chemistry. Biotechnical and Biomedical Applications. Ed. J. Milton Harris, Plenum Press (1992), or conjugates of PEG with colony Stimulating Factor (CSF-1) as described by Katre N. V. in The conjugation of proteins with polyethylene glycol and other polymers. Adv. Drug Delivery Reviews, 10, 91-114 (1993), all incorporated herein by reference. In certain embodiments, the preferred biodegradable polymer is PLGA.

[0078] Suitable biocompatible, non-biodegradable polymers include, but are not limited to, polyvinyl alcohol, polyacrylates; ethylene-vinyl acetates; acyl substituted cellulose acetates; non-degradable polyurethanes; polystyrenes; polyvinyl chlorides; polyvinyl fluorides; poly(vinyl imidazoles); chlorosulphonate polyolefins; polyethylene oxides; or blends or copolymers thereof.

[0079] Suitable lipid-based nanoparticle or microparticle carriers are well known in the art, examples of which include, but are not limited to ionizable lipids (e.g. DLin-MC3-DMA (MC3), C12-200, C14-4, CKK-E12, SM-102, and ALC-0315), phospholipids (e.g., 1,2-distearoyl-sn- glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and egg phosphatidylcholine (EPC)), cholesterol, PEGylated lipids (e.g., 1,2-dimyristoyl-rac- glycero-3-methoxypolyethylene glycol-2000 (DMG-PEG2000), 1,2-distearoyl-sn-glycero-3- phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000)), cationic lipids (e.g., 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3- ethylphosphocholine (DOEPC), Dimethyldioctadecylammonium bromide (DDAB)), and neutral lipids (e.g., 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC)).

[0080] In certain embodiments, the dispersed nanoparticle or microparticle load may comprise from 1 – 20% (wt / wt) based on the weight of the pharmaceutical composition. In certain embodiments, the dispersed nanoparticle or microparticle load may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% (wt / wt) based on the pharmaceutical composition. More particularly the dispersed nanoparticle or microparticle load may comprise 10 – 20%. In certain embodiments, the dispersed nanoparticle or microparticle load may comprise 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% (wt / wt) based on the pharmaceutical composition. In certain embodiments, the preferred nanoparticle or microparticle load is 10% (wt / wt) of the pharmaceutical composition.

[0081] Methods for manufacturing and characterizing the nanoparticles or microparticles has been described in US patent no.9,205,046 which is incorporated herein by reference in its entirety and in Example 2 herein.

[0082] In certain embodiments, the pharmaceutical composition(s) described herein is a solid at room temperature, experiences shear thinning when subjected to applied pressure (e.g., during injection), and reverts to a solid gel once the pressure is removed.

[0083] In one embodiment, the manufacture of the pharmaceutical composition comprising the hydrogel polymer matrix formulation, and the nanoparticle formulation dispersed therein is described in Example 3.

[0084] In one embodiment, there is provided a method of treating cancer comprising administering to a solid tumor in a subject in need thereof a therapeutically effective amount of a pharmaceutical composition described herein comprising least one first anticancer drug, wherein the administration is performed intratumorally.

[0085] Certain embodiments involve the systemic administration of at least one second anticancer drug in addition to the intratumoral delivery of a pharmaceutical composition comprising a first anticancer drug. In some embodiments, the second anticancer drug can be administered via one or more of the following routes: oral, intravenous (IV), intramuscular (IM), subcutaneous (SC or SQ), transdermal, rectal, inhalation, intranasal, intrathecal, intraosseous (IO), and intra-arterial. Intravenous delivery of the at least one second anticancer drug is preferred.

[0086] While certain embodiments provide for pharmaceutical compositions which may comprise more than one first anticancer drug, it is preferrable that the pharmaceutical compositions comprise a nanoparticle of microsphere formulation comprising only one first anticancer drug. In certain embodiments, the pharmaceutical compositions described herein comprise a nanoparticle or microsphere formulation consisting of only one first anticancer drug. In certain embodiments, the method may include the systemic administration of more than one second anticancer drug in combination with the pharmaceutical compositions described herein.

[0087] In some embodiments, while the first and second anticancer drugs may be identical, it is preferable that they differ. When the first and second anticancer drugs are identical, the systemic dosage of the second drug may be lower than the standard dose typically administered under standard care. In embodiments where the first and second anticancer drug differ, it is preferrable that the first anticancer drug is a taxane, and the second drug is preferably an immune checkpoint inhibitor (ICI). Preferably in some embodiments, the taxane is docetaxel, and the second anticancer drug is an anti-CTLA4 inhibitor.

[0088] In certain embodiments, the intratumoral administration may be performed using a delivery device selected from the group consisting of syringes, cannulas, and microinjectors. In certain embodiments, the use of a cannula is preferred.

[0089] The dosage and dosing regimen of the pharmaceutical composition and / or second anticancer drug administered to a subject may vary based on factors such as the type and severity of the disease (e.g., type of cancer, its stage, and the location of the cancer within the body), aswell as the subject's characteristics, including species (human or animal), general health, age, sex, body weight, and drug tolerance. A skilled professional can determine the appropriate dosage and dosing regimen of the pharmaceutical composition, whether used alone or in combination with a second anticancer drug, by taking these and other factors into account. Typically, a therapeutically effective amount of the pharmaceutical composition is sufficient to achieve a therapeutic or prophylactic effect. In other embodiments, when the pharmaceutical composition is administered in combination with the second anticancer drug, a therapeutically effective amount of the combination is sufficient to achieve a therapeutic or prophylactic effect.

[0090] In certain embodiments, the method of treating cancer may comprise the intratumoral administration of a therapeutically effective amount of least two or more pharmaceutical compositions, wherein each composition comprises a distinct first anticancer drug formulated as nanoparticles or microparticles dispersed in a hydrogel polymer matrix described herein. In certain embodiments, one of the distinctly different first anticancer drugs may be identical to the second anticancer drug administered systemically. In methods comprising administration of multiple pharmaceutical compositions, it is preferrable that the nanoparticles or microparticles dispersed in the hydrogel matrix therein comprise only one first anticancer drug.

[0091] In certain embodiments, the pharmaceutical compositions and the at least one second anticancer drug are administered simultaneously, repetitively, in sequence, or in any combination thereof. For example, therapeutically effective amounts may be administered via a single dose or via multiple doses (e.g., at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten doses). When administered via multiple doses, any of a variety of suitable therapeutic regimens may be used, including administration at regular intervals (e.g., once every other day, once every three days, once every four days, once every five days, thrice weekly, twice weekly, once a week, once every two weeks, once every three weeks, etc.).

[0092] The dosage regimen (e.g., amounts of each pharmaceutical composition that is effective in the methods of treatment may depend on the severity of the disease or condition and the weight and general state of the subject. For example, the therapeutically effective amount of a particular composition comprising an anticancer drug applied to a subject (e.g., humans) can be determined by the ordinarily skilled artisan with consideration of individual differences in age, weight, and the condition of the mammal. Therapeutically effective and / or optimal amounts can also be determined empirically by those of skill in the art.

[0093] In some embodiments, administration of the pharmaceutical compositions results in a measurable improvement in the subject. For example, this improvement may include any combination of tumor growth inhibition, tumor growth reduction, tumor regression, inhibition or reduction of metastases, prevention of recurrence, improved survival, or improvement in any clinical sign indicative of cancer status or progression.

[0094] In embodiments providing for the administration of multiple pharmaceutical compositions, the compositions may be co-administered or administered sequentially after administration of one of the pharmaceutical compositions.

[0095] Examples of the first and second anticancer drugs include but are not limited to alkylating agents (e.g, cyclophosphamide (Cytoxan®), ifosfamide (Ifex®), melphalan (Alkeran®), busulfan (Myleran®), chlorambucil (Leukeran®)); antimetabolites (e.g., methotrexate (Trexall®, Rheumatrex®), 5-Fluorouracil (5-FU), Cytarabine (Ara-C®), Gemcitabine (Gemzar®), Capecitabine (Xeloda®)); taxanes (e.g., paclitaxel (Taxol®), docetaxel (Taxotere®), cabazitaxel (Jevtana®)); vinca alkaloids (e.g, vincristine (Oncovin®), vinblastine (Velban®), vinorelbine (Navelbine®)); topoisomerase inhibitors (e.g., etoposide (VePesid®, Etopophos ®), irinotecan (Camptosar®), topotecan (Hycamtin®), teniposide (Vumon®)); epothilones (e.g., ixabepilone (Ixempra®)); halichondrins (e.g., eribulin (Halaven®); anthracyclines (e.g., doxorubicin (Adriamycin®), daunorubicin (Cerubidine®), epirubicin (Ellence®), idarubicin (Idamycin®), mitoxantrone (Novantrone®); antitumor antibiotcis (e.g., dactinomycin (Actinomycin® D), mitomycin C (Mutamycin®)); immune checkpoint inhibitors which include anti-PD-1 monoclonal antibodies (e.g., pembrolizumab (Keytruda®), nivolumab (Opdivo®), cemiplimab (Libtayo®)), anti-PD-L1 monoclonal antibodies (e.g., atezolizumab (Tecentriq®), durvalumab (Imfinzi®), avelumab (Bavencio®), and and-CTLA-4 monoclonal antibodies (e.g., ipilmumab (Yervoy®), tremelimumab (Imjudo®)); angiogenesis inhibitors, (e.g., bevacizumab (Avastin®), ramucirumab (Cyramza®), Zif-aflibercept (Zaltrap®), sunitinib (Sutent®), sorafenib (Nexavar®), pazopanib (Votrient®), cabozantinin (Cometriq®, Cabometyx®), lenvatinib (Lenvima®), axitinib (Inlyta®), regorafenib (Stivarga®)); platinum based agents (e.g., cisplatin (Platinol®), carboplatin (Paraplatin®), oxaliplatin (Eloxatin®), nedaplatin (Aqupla®), satraplatin (codenamed JM216)); hormonal agents (e.g., tamoxifen (Nolvadex ®), anastrozole (Arimidex®), raloxifene (Evista®), letrozole (Femara®), exemestane (Aromasin®), bicalutamide (Casodex®), enzalutamide (Xtandi®)); targeted therapy agents (e.g., trastuzumab (Herceptin®), imatinib (Gleevec®), rituximab (Rituxan®), erlotinib (Tarceva®), sunitinib (Sutent®), sorafenib (Nexavar®), bortezomib (Velcade®), carlfizomib (Kyprolis®)), and any combinations thereof. In certain embodiments, thefirst and second anticancer drug may be a taxane. In certain embodiments, the taxane may be docetaxel.

[0096] In certain embodiments, the first anticancer drug comprises 0.1% – 10% (wt / wt) of the pharmaceutical composition. In certain embodiments, the first anticancer drug comprises 0.6% – 5% (wt / wt) of the pharmaceutical composition. In certain embodiments, the first anticancer drug comprises 0.6% – 2% (wt / wt) of the pharmaceutical composition. In certain embodiments, where the preferred first anticancer drug is docetaxel, the docetaxel may be comprise 0.6% – 2% (wt / wt) of the pharmaceutical composition.

[0097] In one embodiment, the cancer to be treated by the pharmaceutical compositions and methods described herein may be any solid tumor. Non-limiting examples of cancers that form solid tumors include skin cancers, sarcomas, adenocarcinomas, blastomas, and brain tumors. Examples of skin cancers include, but are not limited to melanoma, basal cell carcinoma, squamous cell carcinoma, and merkel cell carcinoma. Examples of melanomas include, but are not limited to nodular melanoma, acral lentiginous melanoma, desmoplastic melanoma, mucosal melanoma, uveal (ocular) melanoma, lentigo maligna melanoma, and superficial spreading melanoma. Examples of sarcomas include, but are not limited to osteosarcoma, Ewing sarcoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, chondrosarcoma, synovial sarcoma, and fibrosarcoma. Examples of adenocarcinomas include, but are not limited to lung adenocarcinoma, breast adenocarcinoma, colorectal adenocarcinoma, pancreatic adenocarcinoma, prostate adenocarcinoma, gastric adenocarcinoma, esophageal adenocarcinoma, ovarian adenocarcinoma, renal adenocarcinoma, and endometrial adenocarcinoma. Examples of blastomas include, but are not limited to neuroblastoma, medulloblastoma, nephroblastoma (Wilms’ Tumor), hepatoblastoma, retinoblastoma, pleuropulmonary blastoma, pancreatoblastoma, and embryonal rhabdomyosarcoma. Examples of brain tumors include, but are not limited to glioblastoma multiforme, astrocytoma, oligodendroglioma, medulloblastoma, ependymoma, meningioma, pituitary adenoma, Schwannoma (neurofibroma), and craniopharyngioma.

[0098] Certain embodiments contemplate a "single-part kit" which may comprise a prefilled syringe containing a pharmaceutical composition with: (1) an anionic gelling polymer, (2) an inverse thermal gelling polymer, and (3) a predetermined dose of a therapeutically effective amount of a nanoparticle or microparticle formulation of a first anticancer drug. The quantities of the inverse thermal gelling polymer and the anionic gelling polymer are selected to create aninjectable hydrogel polymer matrix that forms a solid gel before injection, undergoes shear thinning during injection, and returns to a solid gel afterward. In some embodiments, the single- part kit may also include a delivery device, such as a syringe, cannula, or microinjector with a suitable bore diameter. Additionally, these kits may come with instructions on the dosing regimen and administration of the pharmaceutical composition to a subject in need. In certain single-part kits, the preferred anionic gelling polymer is hyaluronan and the preferred inverse thermal gelling polymer is methylcellulose present in a ratio of 1:1 (wt / wt) of the pharmaceutical composition.

[0099] Certain embodiments contemplate "multi-part kits" comprising: (1) a first part comprising a predetermined dose of a therapeutically effective amount of a nanoparticle or microparticle formulation of a first anticancer drug, and (2) a second part comprising an injectable hydrogel polymer matrix formulation comprising: (a) an anionic gelling polymer, and (b) an inverse thermal gelling polymer. The quantities of the anionic gelling polymer and the inverse thermal gelling polymer are selected to produce a hydrogel polymer matrix that forms a solid gel before injection, undergoes shear thinning during injection, and returns to a solid gel after injection. The first and second parts are to be combined prior to administration to a subject in need. Additionally, the multi-part kits may comprise a range of delivery devices such as syringes, cannulas, and microinjectors, which may have different bore diameters. These kits may also come with instructions on the dosing regimen and how to mix the hydrogel polymer matrix formulation with the nanoparticle or microparticle formulation before administration. In certain embodiments, multi part kits may further comprise a therapeutically effective amount of at least one second anticancer drug. In certain multi-part kits, the preferred anionic gelling polymer is hyaluronan and the preferred inverse thermal gelling polymer is methylcellulose present in a ratio of 1:1 (wt / wt) of the pharmaceutical composition.

[0100] The embodiments described herein are further detailed in the following examples. While these examples illustrate preferred embodiments of the compositions, they are provided solely for illustration and should not be interpreted as limiting the appended claims. Based on the preceding discussion and these examples, a skilled professional can discern the essential characteristics of the various embodiments and, without departing from their spirit and scope, can make adjustments and modifications to adapt them to different uses and conditions.EXAMPLE 1 Preparation and Sterilization of Injectable Hydrogels Preparation of Injectable Hydrogel Formulation

[0101] The hydrogel formulation was prepared using sodium hyaluronate (Lifecore Biomedical, part#80081), methylcellulose (Methocel™ A4M) and Dulbecco's Phosphate-Buffered Saline (D-PBS) without calcium and magnesium (Gibco). This formulation is abbreviated “HAMC”. The amount of sodium hyaluronate (HA) and methylcellulose (MC) in the HAMC formulation was 2% w / v, and the final volume was adjusted with D-PBS. A SpeedMixer (FlackTek SpeedMixer, DAC 330-100 SE) was used to mix the materials and make the hydrogel. First, HA was removed from the freezer and allowed to reach room temperature before weighing it. Then, both polymers were weighed using an analytical balance (Mettler Toledo Inc.), allowing an error margin of + / - 0.15 mg, and added into the speed mixing cups. Based on the final volume of the HAMC hydrogel formulation to be prepared, the correct volume of D-PBS was slowly added to the speed mixing cup containing the HA and MC. The speed mixing cup was firmly closed and vortexed for ~30 seconds at 3000 rpm. Then, using the correct speed mixing cup adapter, the speed mixing cup containing the polymers and D-PBS was placed into the SpeedMixer and run at 3500rpm for 1 minute. Once the polymers were homogenously mixed with the D-PBS, the lid of the speed mixing cup was covered with parafilm, and the HAMC hydrogel formulation stored overnight at 4oC to allow fully hydration of the MC. The next day, the HAMC hydrogel formulation was speed mixed again at 3500rpm for 1 minute, and then centrifuged at 3000 xg for 1.5 hours in a swinging bucket centrifuge (Allegra X-30R Centrifuge, Beckman Coulter™). The HAMC hydrogel formulation was then sterilized using an autoclave, following the protocol described below. After autoclaving and adjusting for water loss, the HAMC hydrogel formulation was speed mixed again at 3500rpm for 1 minute. The speed mixing cup containing the HAMC hydrogel formulation was then covered with parafilm and stored at 4oC until further use. Sterilization of the Injectable HAMC Hydrogel Formulation

[0102] Prior to sterilization of the HAMC hydrogel formulation, the speed mixing cup containing the HAMC hydrogel formulation was removed from the refrigerator and allowed to reach room temperature. Then, autoclaving tape was added to the container comprising the HAMC hydrogel formulation, and the total weight of the container was recorded using an analytical balance (Mettler Toledo Inc.). The container with the HAMC hydrogel formulation was placed inan autoclave bucket and 20-30mL of water was added to the bucket. Then, it was autoclaved using a Getinge 400LS / 500 LS series steam sterilizer with a sterilization temperature of 121°C, exposure time of 20 mins, with a cycle and exhaust for liquids. When the autoclave cycle was finished, the container with the HAMC hydrogel formulation was allowed to cool down to room temperature for about 2 hours. Then, the lid was closed, and any remaining water was wiped off the container prior to weighing it using the same analytical balance as before the sterilization. The weight after autoclaving was recorded and the amount of water lost during the sterilization was calculated based on the difference in weight before and after autoclaving. In a biosafety cabinet and using a P1000 pipette, the required amount of sterile milliQ water was added to the HAMC hydrogel formulation to compensate for water loss. The water was mixed with the HAMC hydrogel formulation by vortexing the container for ~30 seconds at 3000 rpm. The HAMC hydrogel formulation was stored at 4oC until further use. EXAMPLE 2 Preparation and Characterization of a Nanoparticle Formulation comprising the First Anticancer Drug Preparation of Nanoparticles comprising the First Ant-Cancer Drug

[0103] The polymeric nanoparticles were prepared with a microfluidic technology (NanoAssemblr® Ignite™, Precision Nanosystems) comprising docetaxel (DCX) (MedChemExpress) as the first anticancer drug, poly(lactic-co-glycolic acid) 50:50 (PLGA, Resomer® 502H, Lactel, Evonik) as the nanoparticle carrier for encapsulating the DCX, acetonitrile (OmniSolv, EMD Millipore) and poly(vinyl alcohol) (PVA, Sigma Aldrich). The day before preparation of the nanoparticles, a 3% PVA solution (with milliQ water) was prepared using a Pyrex container and heated up to 80⁰C (while stirring with stir bar) for faster solubilization. Once dissolved, the PVA solution was left on the lab bench to reach room temperature prior filtration through a 0.2um PES filter (ThermoFisher).

[0104] The synthesis of the DCX / PLGA nanoparticles involved 4 steps: (1) preparation of the nanoparticles with the Nanoassemblr, (2) dialysis, (3) washing / isolation of the particles, and (4) lyophilization.

[0105] The chip used to make the particles with the Nanoassemblr was suitable for a final volume of 20mL of formulation. Therefore, the volume of the organic and aqueous phases was10mL each (1:1 ratio). The aqueous phase used was the 3% PVA solution previously prepared (as described above). The organic phase contained 2mg / mL of DCX and 10mg / mL of PLGA dissolved in acetonitrile. To make the organic phase, both DCX and PLGA were added to the acetonitrile and allowed to dissolve on an orbital shaker at 140 rpm for 1 hour, at room temperature. Once the components of the organic phase were fully dissolved, 10mL of the organic phase was drawn into a 10mL syringe (BD 10mL Syringe, Luer-Lok) and covered with a syringe cap to avoid evaporation. Similarly, 10mL of the aqueous phase (3% PVA) was drawn up into a 10mL syringe (BD 10mL Syringe, Luer-Lok) and covered with a syringe cap. Then, the Nanoassemblr cartridge was attached to the machine, as well as the syringes containing the organic and the aqueous phases (in positions C and R, respectively), and the Falcon tubes to collect the particles and the waste. The parameters selected to produce the DCX / PLGA nanoparticles were the following: syringes BD10mL for C and R, flow rate for C:R was 1:1, total volume 20mL, total flow 1mL / min, dilution ratio (L: (C+R)) 0:0, start waste 0.3mL, and end waste 0.1mL. The tube containing the nanoparticles was next dialyzed as described below.

[0106] 1-2 hours prior to synthesis of the nanoparticles with the Nanoassemblr, a dialysis membrane (SpectraPro® 2Dialysis Membrane, MWCO 12-14kD) was cut and placed in a 4L beaker filled with milliQ water. The collected nanoparticles were transferred to the pre-wet dialysis membrane using a serological pipette, placed in a beaker containing 4L of milliQ water and left on stir plate at 120 rpm for 1 hour. After 1 hour, the membrane comprising the nanoparticles was transferred to another 4L beaker filled with fresh milliQ water and left on the stir plate overnight.

[0107] After overnight dialysis, the nanoparticles were transferred using a serological pipette from the dialysis membrane into a round bottom 50mL centrifuge tube (suitable for high-speed centrifuge). If cloudy remnants were still visible in the dialysis membranes, a small amount of sterile milliQ water was added into the membrane and rinsed out into the centrifuge tubes. Particles were centrifuged at 17700 g, 4⁰C for 20 min (Avanti JE, Beckman Coulter). After the centrifugation step, particles were washed as follows: approximately half of the supernatant was removed using serological pipettes, the pellet was vortexed for 30 seconds at 3000rpm, bath sonicated for 5 minutes (Symphony™, VWR), and the removed water was replaced by same amount of sterile milliQ water. The centrifugation and washing steps were repeated twice. After the final washing step, the formulation was transferred to a 50mL bioreactor tube (CELLTREAT®, Scientific Products) that was previously labelled and weighed (empty) on an analytical balance (Mettler Toledo Inc.). The bioreactor tube containing the DCX / PLGA nanoparticles was frozen in liquid nitrogen and lyophilized (LABCONCO®, FreezeZone 4.5Plus). The bioreactor containingthe dry particles was weighed again using the same analytical balance, and the yield was calculated as the difference in weigh respect to the empty bioreactor. Characterization of DCX / PLGA Nanoparticles

[0108] After lyophilization, 0.5-1mg of DCX / PLGA nanoparticles were weighed in a 2mL Eppendorf tube using an analytical balance (Mettler Toledo Inc.). MilliQ water was added to the particles to reach a final concentration of 1mg / mL. The particles in water were vortexed for 30 seconds at 3000 rpm, and bath sonicated (Symphony™, VWR) for 5 minutes to ensure they were evenly dispersed. To check the size of the particles, the 1mg / mL of particles was 100x diluted with water, transferred to a cuvette, and analyzed using a zetasizer (Zetasizer Nano ZS, Malvern Panalytical). To analyze the charge, particles were dispersed in 1mM KCl solution to a final concentration of 0.1mg / mL, vortexed for 30 seconds, transferred to a folded capillary cell (Malvern), and analyzed using a zetasizer (Zetasizer Nano ZS, Malvern Panalytical). EXAMPLE 3 Preparation of a Pharmaceutical Composition comprising a Nanoparticulate Formulation of a First Anticancer Drug Dispersed in an Injectable HAMC Hydrogel Polymer Matrix Formulation

[0109] The DCX / PLGA nanoparticles in the HAMC hydrogel formulation was prepared using sterile HAMC 2:2, DCX / PLGA nanoparticles (both obtained as described above) and D-PBS without calcium and magnesium (Gibco). The final formulation contained 10% of DCX / PLGA nanoparticles (w / v) entrapped in HAMC 1:1. To ensure sterility, all the procedure was done in a laminar flow previously cleaned with 70% ethanol and using sterile / autoclaved materials.

[0110] Based on the final volume of the pharmaceutical composition to be prepared, DCX / PLGA nanoparticles were weighed (using a smooth tipped forceps and a small spatula) in a 2mL Eppendorf tube using an analytical balance (Mettler Toledo Inc.). Particles were then centrifuged at 3000xg for 1 minute (Microfuge® Centrifuge, Beckman Coulter™), or until they sediment in the bottom of the tube. Considering the desired final volume of the pharmaceutical composition, the required amount of HAMC 2:2 was added to the inside wall of the Eppendorf tube containing the DCX / PLGA nanoparticles so the final concentration of HAMC is 1:1 (ie. HAMC 2:2 represents the 50% of the final formulation). Then, the required amount of D-PBS (40% of the final volume) was added to the Eppendorf tube containing both the nanoparticle and HAMChydrogel formulation. The tube was then covered with parafilm, placed horizontally into a speed mixing cup and speed mixed at 3000 rpm for 1 minute. After the mixing, the tube containing the pharmaceutical composition was centrifuged at 2000 xg for 1 minute at 4oC in a swinging bucket centrifuge (Allegra X-30R Centrifuge, Beckman Coulter™) using a 50mL Falcon tube with an adaptor. Then, the tube was placed upside down into a speed mixing cup, speed mixed at 3000 xg for 1 minute and centrifuged under the same conditions. Finally, the tube was placed up right into a speed mixing cup, speed mixed at 3000 xg for 1 minute and centrifuged again. After the last centrifugation step, a hole was introduced (using a 1” 21 G needle) at the center and bottom of the 2 mL Eppendorf tube containing the pharmaceutical composition. This allowed the transfer of the pharmaceutical composition directly into a previously weighed syringe by placing the tube vertically on top of a 1 mL syringe with the hole created directly above the back of the 1 mL syringe and pushing the pharmaceutical composition out of the Eppendorf tube through the hole with the plunger of a 3mL syringe (backfilling). Due to the multiple mixing steps, bubbles were observed after transferring the pharmaceutical composition into the 1mL syringe. Then, a syringe cap was placed on the syringe containing the final pharmaceutical composition and it was stored at 4oC with the tip up until use. This way, the bubbles can move to the tip of the syringe and, right before using the pharmaceutical composition, the bubbles can be pushed out of the syringe. EXAMPLE 4 In vivo Antitumor Efficacy of the Pharmaceutical Composition comprising a Nanoparticulate Formulation of a First Anticancer Drug Dispersed in an Injectable HAMC Hydrogel Polymer Matrix Formulation

[0111] Sixty-five athymic nude mice (J:NU) aged 6-8 weeks with a weight of 25 ± 2 g (at the moment of starting the experiment), and 35 Balb / cJ mice aged 6-8 weeks with a weight of 21 ± 2 g (at the moment of starting the experiment) were obtained from Jackson Labs. Specific pathogen free cages, each with high efficiency particulate air filter, attached to a ventilated rack unit (Allentown, USA) were used to house the mice. Sterile food, water and bedding were provided, and mice were housed under a standardized 12 / 12 h light / dark cycle at a room temperature of 24 ± 2°C and a humidity of 60%. Sterile bedding was changed every 10 days. All in vivo studies were conducted according to ethical guidelines and were approved by the ethical committee of University Health Network, Canada.

[0112] A549 cells (CCL-18™, ATCC) were selected as a model for lung cancer. The cells were used at a passage <15 and were maintained in DMEM culture medium (Gibco) with 10% fetal bovine serum (FBS, Invitrogen) (complete medium), without antibiotics. Cells were prepared as follows to establish subcutaneous tumors in mice. Eighty percent confluent cultures in T75 flasks were trypsinized and resuspended in 10 mL of cold fresh complete medium, the cells were collected by centrifugation at 200 xg, 4oC for 5 minutes and washed with a sterile D-PBS in order to remove the trypsin.

[0113] The A549 cell pellet was resuspended in 10 mL of cold serum-free medium, centrifuged at 200 xg, 4oC for 5 minutes,and resuspended again with 10mL of cold serum-free medium. Cells were then filtered through a 70um sterile cell strainer (Fisherbrand, 70um nylon mesh), counted and centrifuged again. The cell pellet was resuspended with 50:50 serum-free medium:Cultrex (Cultrex PathClear BME, Type 3,R&D Systems) to get a final concentration of 2.5 ×106cells in 100uL, and kept in ice.

[0114] Nude mice were anesthetized with isoflurane. The injection area was cleaned with a betadine solution followed by 70% ethanol. Then, mice were injected subcutaneously in the right flank with 2.5 ×106cells in 100 µL 50:50 serum-free medium:Cultrex using a 26G needle attached to a 1mL syringe. In between injections, the cells were kept in ice. The injection site was inspected to ensure no leakage of cells. Mice were kept under anesthesia for 2min before returning to their home cages. After cell implantation, mice were checked daily, and body weight and tumor volume were recorded 3-times per week. Tumor volume (mm3) was determined using a digital caliper (VWR Carbon DTL Caliper) by applying the following equation: Tumor volume (mm3) = Length (mm) × Width (mm) × Width (mm) / 2 When the average tumor volume reached approximately 250-300 mm3, mice were randomized to ensure each treatment group had a mean tumor volume of 250mm3, and treatment started (day 0). The experiment involved 4 treatment groups: 1) Control group received 5uL of PBS injected intratumorally (IT) (n=20); 2) Systemic treatment (IP) with DCX solution (10mg / mL, Sandoz, Novartis) at 20mg / kg every 4days (n=10); 3) Local treatment (IT) with 5 uL of DCX / PLGA nanoparticles in HAMC (total dose of DCX ~2mg / kg) (n=18), injected on day 0; 4) Local treatment (IT) with 5 uL of DCX solution (10mg / mL, ~2mg / kg) (n=10), injected on day 0.

[0115] Mice were checked daily. Body weight (as a surrogate for toxicity) and tumor volume were recorded 3-times per week until the end of the experiment. Mice were sacrificed when thetumor volume reached >1500 mm3or when mice lost 20% of their original body weight, as a sign of extreme toxicity. When mice started showing signs of toxicity (ie. loss of 10% of original body weight), the systemic treatment stopped and resumed once the mice returned to their original body weight; otherwise, mice would succumb to toxicity. At the end of experiment, animals were euthanized by CO2followed by cervical dislocation. Treatment efficacy was analyzed based on delay of tumor growth and overall survival, whereas safety was analyzed based on body weight loss.

[0116] CT26 cells (CRL-2639, ATCC) were selected as a model for colorectal cancer. The cells were used at a passage <15 and were maintained in RPMI 1640 medium (Sigma Aldrich) with 10% FBS (Invitrogen) (complete medium), without antibiotics. Cells were prepared as previously described for A549 cells to establish subcutaneous tumors in mice, but to a final concentration of 1 ×106cells in 100uL of 50:50 serum-free medium:Cultrex, and kept in ice.

[0117] The implantation of CT26 cells in Balb / c mice was performed following a procedure similar to the one described above for A549 cells, but mice were shaved prior to anesthesia). One million cells in 100uL of 50:50 serum-free medium:Cultrex were injected in the right flank of mice. After cell implantation, mice were checked daily, and body weight and tumor volume were recorded 3-times per week. Tumor volume was determined using a digital caliper, as described above.

[0118] When the average tumor volume reached approximately 100 mm3, mice were randomized to ensure each treatment group had a mean tumor volume of 100mm3, and treatment started (day 0). The experiment involved 6 treatment groups: 1) Control group received 5uL of PBS injected intratumorally (IT) and 10mg / kg of the Isotype control for anti-CTLA4 antibody (InVivoMAb polyclonal Syrian hamster IgG, BioXCell) every 3 days, by intraperitoneal injection (IP) (n=5); 2) Systemic treatment (IP) with DCX solution (10mg / mL, Sandoz, Novartis) at 20mg / kg every 4days (n=5); 3) Systemic treatment (IP) with 10mg / kg of antiCTLA4 antibody (InVivoMAb anti-mouse CTLA4 clone 9H10, BioXCell) every 3 days, 6 doses (n=6); 4) Systemic combination (IP) of antiCTLA4 and DCX solution, as previously described (n=6); 5) Local treatment (IT) with 5 uL of DCX / PLGA nanoparticles in HAMC (total dose of DCX 1.4mg / kg) (n=6), injected on day 0 and 14; 6) Treatment combination of local (IT) DCX / PLGA nanoparticles in HAMC and systemic (IP) anti-CTLA4 antibody, as previously described (n=6).

[0119] Mice were checked daily. Body weight (as a surrogate for toxicity) and tumor volume were recorded 3-times per week until the end of the experiment. Mice were sacrificed when the tumor volume reached >1500 mm3or when mice lost 20% of their original body weight as a sign of extreme toxicity. When mice started showing signs of toxicity (i.e. loss of 10% of original body weight), the systemic treatment stopped and resumed after the mice returned to their original body weight; otherwise, mice would succumb to toxicity. At the end of experiment, animals were euthanized by CO2followed by cervical dislocation. Treatment efficacy was analyzed based on delay of tumor growth and overall survival, whereas safety was analyzed based on body weight loss.

[0120] Further embodiments include the subject matter of the following clauses: 1. A method of treating cancer comprising: administering intratumorally to a solid tumor in a subject in need thereof a therapeutically effective amount of an injectable pharmaceutical composition, the injectable pharmaceutical composition comprising at least one first anticancer drug formulated as nanoparticles or microparticles and a hydrogel polymer matrix comprising from 0.1 % – 3.0% (wt / wt) methylcellulose and from 0.1% – 3.0% (wt / wt) hyaluronan, wherein the nanoparticle or microparticles are dispersed in the hydrogel polymer matrix. 2. The method of clause 1, wherein the pharmaceutical composition contains only one first anticancer drug. 3. The method of clause 1, wherein the pharmaceutical composition contains more than one, preferably only two, first anticancer drugs. 4. The method of clause 3, wherein the anticancer drugs of the pharmaceutical composition are co-encapsulated. 5. The method of any one of clauses 1-4, wherein the first anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum-based agents, hormonal agents, targeted therapy agents, and any combination thereof.6. The method of any one of clauses 1-5, wherein the first anticancer drug is a taxane, preferably wherein the first anticancer drug is docetaxel. 7. The method of any one of clauses 1-6, further comprising administering to the subject a therapeutically effective amount of at least one second anticancer drug. 8. The method of clause 7, wherein the therapeutically effective amount of the at least one second anticancer drug is administered systemically. 9. The method of clause 7 or 8, wherein the pharmaceutical composition and the at least one second anticancer drug are administered simultaneously, repetitively, in sequence, or in any combination thereof. 10. The method of any one of clauses 7-9, wherein the second anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum-based agents, hormonal agents, targeted therapy agents, and any combination thereof. 11. The method of clause 10, wherein the at least one second anticancer drug is an immune checkpoint inhibitor. 12. The method of any one of clauses 7-11, wherein the at first and second anticancer drug are the same. 13. The method of any one of clauses 7-11, wherein the first and second anticancer drug are different. 14. The method of clause 11, wherein the immune checkpoint inhibitor is selected from the group consisting of an anti-PD-1 monoclonal antibody, an anti-PD-L1 monoclonal antibody, an anti-CTLA-4 monoclonal antibody, and any combination thereof. 15. The method of clause 14, wherein the at least one second anticancer drug is an anti- CTLA-4 monoclonal antibody. 16. The method of any one of clauses 1-15 comprising intratumorally administering a therapeutically effective amount of a first injectable pharmaceutical composition as defined in claim 1 comprising a first anticancer drug and intratumorally administering a secondinjectable pharmaceutical composition as defined in claim 1 comprising a different first anticancer drug. 17. The method of any one of clauses 1-16, wherein the intratumoral administration is performed using a delivery device selected from the group consisting of syringes, cannulas, and microinjectors. 18. The method of clause 17, wherein the intratumoral administration is performed using a cannula. 19. The method of any one of clauses 1-18, wherein the hydrogel polymer matrix provides for sustained release of the nanoparticles or microparticles. 20. The method of clause 19, wherein the hydrogel polymer matrix provides for zero-order sustained release of the nanoparticles or microparticles. 21. The method of any one of clauses 1-20, wherein the nanoparticles or microparticles comprise a biodegradable polymer wherein the biodegradable polymer encapsulates the first anticancer drug. 22. The method of clause 21, wherein the biodegradable polymer is PLGA 23. The method of any one of clauses 1-22, wherein the injectable pharmaceutical composition forms a solid gel prior to injection, undergoes shear thinning upon injection, and returns to a solid gel after injection. 24. The method of any one of clauses 1-23, wherein the nanoparticles have an average particle diameter of from 150 nm – 250 nm. 25. The method of any one of clauses 1-24, wherein the nanoparticle or microparticle load comprises from 1 – 20% (wt / wt) based on the injectable pharmaceutical composition. 26. The method of clause 25, wherein the nanoparticle or microparticle load comprises 10% (wt / wt) based on the injectable pharmaceutical composition. 27. A pharmaceutical composition comprising a therapeutically effective amount of one first anticancer drug formulated as nanoparticles or microparticles dispersed in an injectablehydrogel polymer matrix comprising from about from 0.1 % – 3.0 % (wt / wt) hyaluronan and from 0.1 % – 3.0% (wt / wt) methylcellulose. 28. The pharmaceutical composition of clause 27, wherein the nanoparticles or microparticles comprise a carrier comprising a biodegradable polymer wherein the carrier encapsulates the first anticancer drug. 29. The pharmaceutical composition of clause 28, wherein the biodegradable polymer is PLGA. 30. The pharmaceutical composition of any one of clauses 27-29, wherein the nanoparticles have an average diameter from 150 nm – 250 nm. 31. The pharmaceutical composition of any one of clauses 27-30, wherein the nanoparticle or microparticle load comprises from 1 – 20% (wt / wt) based on the pharmaceutical composition. 32. The pharmaceutical composition of clause 31, wherein the nanoparticle or microparticle load comprises 10% (wt / wt) based on the pharmaceutical composition. 33. The pharmaceutical composition of any one of clauses 27-32, wherein the first anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum- based agents, hormonal agents, targeted therapy agents, and any combination thereof. 34. The pharmaceutical composition of any one of clauses 27-33, wherein the nanoparticle or microparticle formulation comprises only one first anticancer drug. 35. The pharmaceutical composition of clause 25 wherein the nanoparticle or microparticle formulation consists of only one first anticancer drug. 36. The pharmaceutical composition of any one of clauses 27-35, wherein the first anticancer drug is a taxane. 37. The pharmaceutical composition of clause 36, wherein the first anticancer drug is docetaxel.38. The pharmaceutical composition of any one of clauses 27-36 adapted for direct intratumoral injection, providing localized delivery and reduced systemic exposure relative to systemic administration of the first anticancer drug in a subject in need thereof. 39. The pharmaceutical composition of any one of clauses 27-38, wherein the pharmaceutical composition is a solid gel prior to injection, undergoes shear thinning upon injection, and returns to a solid gel after injection 40. The pharmaceutical composition of any one of clauses 27-39, wherein the composition is formulated for administration using a delivery device selected from the group consisting of a syringe, a cannula, and a microinjector. 41. A kit comprising a first part comprising an injectable hydrogel formulation and a second part comprising a therapeutically effective amount of nanoparticles or microparticles comprising at least one first anticancer drug, wherein the first and second parts are admixed to form a pharmaceutical composition according to any one of claims 27-40. 42. The kit of clause 41, further comprising directions on how to admix the first and second parts. 43. A kit comprising a prefilled syringe comprising the pharmaceutical composition of any one of clauses 27-40. 44. The kit of any one of clauses 41-43 further comprising directions on how to administer the pharmaceutical composition. 45. The kit of any one of clauses 41-44 further comprising a therapeutically effective amount of a second anticancer drug. 46. The kit of clause 45 further comprising directions on how to administer the second anticancer drug. 47. The kit of clause 45 or 46, wherein the second anticancer drug is formulated for systemic administration. 48. The kit of clause 46, wherein the nanoparticle or microparticle formulation comprises only one first anticancer drug.49. The kit of any one of clauses 41-48 further comprising a plurality of delivery devices selected from syringes, cannulas, and microinjectors. 50. The kit of clause 49 further comprising a plurality of cannulas comprising bores of different diameters. 51. The kit of clause 49, wherein the delivery devices comprise bores of different diameter. 52. Use of the pharmaceutical composition of any one of clauses 27-40 or the kit of any one of clauses 41-51 for treating cancer in a subject in need thereof. 53. The method of any one of clauses 1-26, the pharmaceutical composition of any one of clauses 27-40 or the kit of any one of clauses 41-51, wherein the ratio of hyaluronan to methylcellulose is from 1:1 (wt / wt) to 1:20 (wt / wt), preferably about 1:1 (wt / wt). 54. The pharmaceutical composition of clause 27, wherein the first anticancer drug is a small molecule and is the sole anticancer drug. 55. The pharmaceutical composition of clause 27, wherein the first anticancer drug is a biologic and is the sole anticancer drug. 56. A sustained release intratumoral drug depot comprising the pharmaceutical composition of any one of clauses 27-40, optionally having a volume between 0.05 mL and 2 mL.

Claims

WHAT IS CLAIMED IS:

1. A method of treating cancer comprising: administering intratumorally to a solid tumor in a subject in need thereof a therapeutically effective amount of an injectable pharmaceutical composition, the injectable pharmaceutical composition comprising at least one first anticancer drug formulated as nanoparticles or microparticles and a hydrogel polymer matrix comprising from 0.1 % – 3.0% (wt / wt) methylcellulose and from 0.1% – 3.0% (wt / wt) hyaluronan, wherein the nanoparticle or microparticles are dispersed in the hydrogel polymer matrix.

2. The method of claim 1, wherein the pharmaceutical composition contains only one first anticancer drug.

3. The method of claim 1, wherein the pharmaceutical composition contains more than one, preferably only two, first anticancer drugs.

4. The method of claim 3, wherein the anticancer drugs of the pharmaceutical composition are co-encapsulated.

5. The method of any one of claims 1-4, wherein the first anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum-based agents, hormonal agents, targeted therapy agents, and any combination thereof.

6. The method of any one of claims 1-5, wherein the first anticancer drug is a taxane, preferably docetaxel.

7. The method of any one of claims 1-6, further comprising administering to the subject a therapeutically effective amount of at least one second anticancer drug.

8. The method of claim 7, wherein the therapeutically effective amount of the at least one second anticancer drug is administered systemically.

9. The method of claim 7 or 8, wherein the pharmaceutical composition and the at least one second anticancer drug are administered simultaneously, repetitively, in sequence, or in any combination thereof.

10. The method of any one of claims 7-9, wherein the second anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum-based agents, hormonal agents, targeted therapy agents, and any combination thereof.

11. The method of claim 10, wherein the at least one second anticancer drug is an immune checkpoint inhibitor.

12. The method of any one of claims 7-11, wherein the at first and second anticancer drug are the same.

13. The method of any one of claims 7-11, wherein the first and second anticancer drug are different.

14. The method of claim 11, wherein the immune checkpoint inhibitor is selected from the group consisting of an anti-PD-1 monoclonal antibody, an anti-PD-L1 monoclonal antibody, an anti-CTLA-4 monoclonal antibody, and any combination thereof.

15. The method of claim 14, wherein the at least one second anticancer drug is an anti-CTLA- 4 monoclonal antibody.

16. The method of any one of claims 1-15 comprising intratumorally administering a therapeutically effective amount of a first injectable pharmaceutical composition as defined in claim 1 comprising a first anticancer drug and intratumorally administering a second injectable pharmaceutical composition as defined in claim 1 comprising a different first anticancer drug.

17. The method of any one of claims 1-16, wherein the intratumoral administration is performed using a delivery device selected from the group consisting of syringes, cannulas, and microinjectors.

18. The method of claim 17, wherein the intratumoral administration is performed using a cannula.

19. The method of any one of claims 1-18, wherein the hydrogel polymer matrix provides for sustained release of the nanoparticles or microparticles.

20. The method of claim 19, wherein the hydrogel polymer matrix provides for zero-order sustained release of the nanoparticles or microparticles.

21. The method of any one of claims 1-20, wherein the nanoparticles or microparticles comprise a biodegradable polymer wherein the biodegradable polymer encapsulates the first anticancer drug.

22. The method of claim 21, wherein the biodegradable polymer is PLGA.

23. The method of any one of claims 1-22, wherein the injectable pharmaceutical composition forms a solid gel prior to injection, undergoes shear thinning upon injection, and returns to a solid gel after injection.

24. The method of any one of claims 1-23, wherein the nanoparticles have an average particle diameter of from 150 nm – 250 nm.

25. The method of any one of claims 1-24, wherein the nanoparticle or microparticle load comprises from 1 – 20% (wt / wt) based on the injectable pharmaceutical composition.

26. The method of claim 25, wherein the nanoparticle or microparticle load comprises 10% (wt / wt) based on the injectable pharmaceutical composition.

27. A pharmaceutical composition comprising a therapeutically effective amount of one first anticancer drug formulated as nanoparticles or microparticles dispersed in an injectable hydrogel polymer matrix comprising from about from 0.1 % – 3.0 % (wt / wt) hyaluronan and from 0.1 % – 3.0% (wt / wt) methylcellulose.

28. The pharmaceutical composition of claim 27, wherein the nanoparticles or microparticles comprise a carrier comprising a biodegradable polymer wherein the carrier encapsulates the first anticancer drug.

29. The pharmaceutical composition of claim 28, wherein the biodegradable polymer is PLGA.

30. The pharmaceutical composition of any one of claims 27-29, wherein the nanoparticles have an average diameter from 150 nm – 250 nm.

31. The pharmaceutical composition of any one of claims 27-30, wherein the nanoparticle or microparticle load comprises from 1 – 20% (wt / wt) based on the pharmaceutical composition.

32. The pharmaceutical composition of claim 31, wherein the nanoparticle or microparticle load comprises 10% (wt / wt) based on the pharmaceutical composition.

33. The pharmaceutical composition of any one of claims 27-32, wherein the first anticancer drug is selected from the group consisting of alkylating agents, antimetabolites, taxanes, vinca alkaloids, topoisomerase inhibitors, epothilones, halichondrins, anthracyclins, antitumor antibiotics, immune checkpoint inhibitors, angiogenesis inhibitors, platinum- based agents, hormonal agents, targeted therapy agents, and any combination thereof.

34. The pharmaceutical composition of any one of claims 27-33, wherein the nanoparticle or microparticle formulation comprises only one first anticancer drug.

35. The pharmaceutical composition of claim 25 wherein the nanoparticle or microparticle formulation consists of only one first anticancer drug.

36. The pharmaceutical composition of any one of claims 27-35, wherein the first anticancer drug is a taxane.

37. The pharmaceutical composition of claim 36, wherein the first anticancer drug is docetaxel.

38. The pharmaceutical composition of any one of claims 27-37 adapted for direct intratumoral injection, providing localized delivery and reduced systemic exposure relative to systemic administration of the first anticancer drug in a subject in need thereof.

39. The pharmaceutical composition of any one of claims 27-38, wherein the pharmaceutical composition is a solid gel prior to injection, undergoes shear thinning upon injection, and returns to a solid gel after injection40. The pharmaceutical composition of any one of claims 27-39, wherein the composition is formulated for administration using a delivery device selected from the group consisting of a syringe, a cannula, and a microinjector.

41. A kit comprising a first part comprising an injectable hydrogel formulation and a second part comprising a therapeutically effective amount of nanoparticles or microparticles comprising at least one first anticancer drug, wherein the first and second parts are admixed to form a pharmaceutical composition according to any one of claims 27-40.

42. The kit of claim 41, further comprising directions on how to admix the first and second parts.

43. A kit comprising a prefilled syringe comprising the pharmaceutical composition of any one of claims 27-40.

44. The kit of any one of claims 41-43 further comprising directions on how to administer the pharmaceutical composition.

45. The kit of any one of claims 41-44 further comprising a therapeutically effective amount of a second anticancer drug.

46. The kit of claim 45 further comprising directions on how to administer the second anticancer drug.

47. The kit of claim 45 or 46, wherein the second anticancer drug is formulated for systemic administration.

48. The kit of claim 46, wherein the nanoparticle or microparticle formulation comprises only one first anticancer drug.

49. The kit of any one of claims 41-48 further comprising a plurality of delivery devices selected from syringes, cannulas, and microinjectors.

50. The kit of claim 49 further comprising a plurality of cannulas comprising bores of different diameters.

51. The kit of claim 49, wherein the delivery devices comprise bores of different diameter.

52. Use of the pharmaceutical composition of any one of claims 27-40 or the kit of any one of claims 41-51 for treating cancer in a subject in need thereof.

53. The method of any one of claims 1-26, the pharmaceutical composition of any one of claims 27-40 or the kit of any one of claims 41-51, wherein the ratio of hyaluronan to methylcellulose is from 1:1 (wt / wt) to 1:20 (wt / wt), preferably about 1:1 (wt / wt).

54. The pharmaceutical composition of claim 27, wherein the first anticancer drug is a small molecule and is the sole anticancer drug.

55. The pharmaceutical composition of claim 27, wherein the first anticancer drug is a biologic and is the sole anticancer drug.

56. A sustained release intratumoral drug depot comprising the pharmaceutical composition of any one of claims 27-40.

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