Monoclonal antibodies targeting conformation-specific epitopes of immunoglobulin light chains of the .LAMBDA. subclass.

Abstract

Provided herein are anti-human λ light chain antibodies or human λ light chain-binding antibody fragments that bind to epitopes specific to human λ light chains. Also provided are polynucleotides and vectors encoding the same, as well as compositions comprising the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments. The anti-human λ light chain antibodies or human λ light chain-binding antibody fragments are useful for measuring human λ light chains in biological samples, which involves contacting the sample with the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments. The anti-human λ light chain antibodies or human λ light chain-binding antibody fragments are also useful for reducing λ light chain aggregates.

Description

[Technical Field]

[0001] cross reference This application claims the benefit of U.S. Provisional Application No. 63 / 351,533, filed June 13, 2022, which is incorporated herein by reference in its entirety. [Background technology]

[0002] Light chain amyloidosis (AL amyloidosis) is a life-threatening secondary condition associated with the primary spectrum disorder plasma cell dysplasia. It is a widely underdiagnosed disease caused by misfolding of free immunoglobulin light chains (LCs), which can deposit as light chain amyloid (AL) in the heart, kidneys, and nervous system. AL amyloidosis occurs in approximately 15% of cases of plasma cell dysplasia, in which a single plasma cell clone undergoes uncontrolled proliferation, resulting in the abnormal production of large amounts of excessive monoclonal free immunoglobulin kappa (κ) or lambda (λ) light chain proteins and their secretion into the circulation. This increased concentration of light chain proteins can lead to a specific type of aggregation and accumulation known as amyloid deposits. Amyloid deposition and infiltration in vital organs, such as the heart, kidneys, and nervous system, can lead to restrictive cardiomyopathy, nephrotic syndrome, hepatomegaly, peripheral neuropathy, and ultimately death.

[0003] AL amyloidosis is the most common type of systemic amyloidosis. In Western countries, the incidence rate is 9–14 cases per million per year. Its prevalence is likely underestimated because the majority of patients remain undiagnosed until after death. The Amyloidosis Foundation estimates that the disease affects more than 35,000–45,000 patients in the United States and the EU, with approximately 12,000 and 18,600 new cases of AL diagnosed annually in the United States and the EU, respectively. Life expectancy for patients diagnosed with AL amyloidosis depends on the extent of organ involvement. For patients with cardiac amyloid deposits (approximately 50%), the prognosis is dire, with a median survival of less than six months from the onset of heart failure symptoms if left untreated. Summary of the Invention

[0004] Described herein are epitopes of the human lambda (λ) light chain and antibodies that bind to human λ epitopes. The epitopes described herein are advantageous because they enable the production and / or screening of antibodies that bind to and promote the clearance of misfolded λ light chains, which are the etiological cause of λ light chain amyloidosis. One obstacle to the treatment of light chain amyloidosis is that different patients produce light chains with different amino acid sequences that are not equally well bound by current anti-light chain antibodies that target the variable region. The antibodies described herein target epitopes in the constant region of the λ light chain, which in certain instances allows for more consistent clinical results and less variability in outcomes between patients. The universality of binding allows for the additional benefit of using the anti-human λ light chain antibodies described herein as part of a diagnostic test for light chain amyloidosis. Furthermore, the anti-human λ light chain antibodies described herein are specific for misfolded light chains and have reduced reactivity to properly folded light chains, thereby reducing the potential for undesired immunological side effects due to reduced antibody levels and avoiding potential sequestration of the therapeutic agent due to undesired off-target binding that interferes with efficacy. Provided herein are anti-λ light chain antibodies, and compositions comprising anti-λ light chain antibodies, for use in treating or diagnosing λ light chain amyloidosis.

[0005] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising: (a) a heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO:3; (b) a heavy chain complementarity determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO:4; (c) a heavy chain complementarity determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO:5; (d) a light chain complementarity determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO:6; (e) a light chain complementarity determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO:7; and / or (f) a light chain complementarity determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO:8. In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment comprises a heavy chain variable region comprising H-CDR1, H-CDR2, and H-CDR3, and / or a light chain variable region comprising L-CDR1, L-CDR2, and L-CDR3.

[0006] In certain embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:1, and / or the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:2.

[0007] Also provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising: (a) heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 13; (b) heavy chain complementarity determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 14; (c) heavy chain complementarity determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 15; (d) light chain complementarity determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 16; (e) light chain complementarity determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 17; and / or (f) light chain complementarity determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 18. In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment thereof comprises a heavy chain variable region comprising H-CDR1, H-CDR2, and H-CDR3, and / or a light chain variable region comprising L-CDR1, L-CDR2, and L-CDR3. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:11, and / or the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:12.

[0008] Further provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising: (a) a heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 23; (b) a heavy chain complementarity determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 24; (c) a heavy chain complementarity determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 25; (d) a light chain complementarity determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 26; (e) a light chain complementarity determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 27; and / or (f) a light chain complementarity determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 28.

[0009] In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment thereof comprises a heavy chain variable region comprising H-CDR1, H-CDR2, and H-CDR3, and / or a light chain variable region comprising L-CDR1, L-CDR2, and L-CDR3. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:21, and / or the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:22.

[0010] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising: (a) a heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 33; (b) a heavy chain complementarity determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 34; (c) a heavy chain complementarity determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 35; (d) a light chain complementarity determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 36; (e) a light chain complementarity determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 37; and / or (f) a light chain complementarity determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 38. In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment thereof comprises a heavy chain variable region comprising H-CDR1, H-CDR2, and H-CDR3, and / or a light chain variable region comprising L-CDR1, L-CDR2, and L-CDR3. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 31, and / or the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 32.

[0011] Also provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding antibody fragment thereof, comprising: (a) heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 43; (b) heavy chain complementarity determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 44; (c) heavy chain complementarity determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 45; (d) light chain complementarity determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 46; (e) light chain complementarity determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 47; and / or (f) light chain complementarity determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 48. In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment comprises a heavy chain variable region comprising H-CDR1, H-CDR2, and H-CDR3, and / or a light chain variable region comprising L-CDR1, L-CDR2, and L-CDR3. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:41, and / or the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:42.

[0012] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain antibody fragment thereof, comprising a heavy chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 1, and / or a light chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 2. Also provided is an anti-human λ light chain antibody, or a human λ light chain antibody fragment thereof, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 1, and / or a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 2.

[0013] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 11, and / or a light chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 12. Also provided and described is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 11, and / or a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 12.

[0014] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 21, and / or a light chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 22. Also provided and described is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 21, and / or a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 22.

[0015] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 31, and / or a light chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 32. Also provided and described is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 31, and / or a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 32.

[0016] Provided and described herein is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 41, and / or a light chain variable region comprising an amino acid sequence having at least about 90%, 95%, 97%, 98%, or 99% identity to SEQ ID NO: 42. Also provided and described is an anti-human λ light chain antibody, or a human λ light chain-binding fragment thereof, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 41, and / or a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 42.

[0017] In some embodiments, the anti-human λ light chain antibody is a monoclonal antibody. In some embodiments, the anti-human λ light chain antibody is a chimeric antibody, a humanized antibody, or a human antibody. In some embodiments, the human λ light chain-binding antibody fragment comprises a Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimer, minibody, or diabody. In some embodiments, the anti-human λ light chain antibody or human λ light chain-binding fragment thereof is an IgG antibody. In some embodiments, the IgG antibody is an IgG1 isotype. In some embodiments, the IgG antibody is an IgG4 isotype. In some embodiments, the anti-human λ light chain antibody or human λ light chain-binding fragment thereof binds to an epitope comprising SEQ ID NO: 51. In some embodiments, binding to an epitope comprising SEQ ID NO: 51 is measured by ELISA, surface plasmon resonance, biolayer interferometry, or isothermal calorimetry.

[0018] In some embodiments, the anti-human λ light chain antibody or human λ light chain binding fragment thereof is conjugated to a label, hi some embodiments, the label comprises a chemical label, a biological label, a fluorescent label, a radioisotope label, or any combination thereof.

[0019] Provided and described herein are pharmaceutical compositions comprising an anti-human λ light chain antibody or a human λ light chain-binding fragment thereof and a pharmaceutically acceptable excipient, diluent, or carrier. Also provided are nucleic acids encoding the anti-human λ light chain antibody or a human λ light chain-binding fragment thereof. Furthermore, host cells containing nucleic acids encoding the anti-human λ light chain antibody or a human λ light chain-binding fragment thereof are also provided.

[0020] Provided and described herein are methods for diagnosing amyloidosis in a sample, comprising contacting a biological sample obtained from a subject with an anti-human λ light chain antibody or human λ light chain binding fragment thereof described herein. Also provided are methods for detecting free light chain polypeptides in a sample, comprising contacting a biological sample with an anti-human λ light chain antibody or human λ light chain binding fragment thereof described herein. Also provided herein are methods for diagnosing amyloid deposits in a sample, comprising contacting a biological sample with an anti-human λ light chain antibody or human λ light chain binding fragment thereof described herein.

[0021] In some embodiments, the sample is derived from blood, serum, plasma, solid tissue, and any combination thereof. In some embodiments, the sample is derived from a subject.

[0022] Provided and described herein are methods for promoting clearance of λ light chain aggregates by monocyte cells, the methods comprising contacting λ light chain aggregates with an anti-human λ light chain antibody, or human λ light chain binding fragment thereof, described herein. Also provided and described herein are methods for increasing clearance of λ light chain aggregates, the methods comprising contacting λ light chain aggregates with an anti-human λ light chain antibody, or human λ light chain binding fragment thereof, described herein.

[0023] Provided is a method for reducing λ light chain aggregates in a subject, the method comprising administering to the subject an anti-human λ light chain antibody, or human λ light chain binding fragment thereof, described herein, thereby reducing the number of λ light chain aggregates in the subject.

[0024] Also provided and described herein are methods for treating a disease or disorder characterized by λ light chain aggregates, comprising reducing the number of λ light chain aggregates in a subject by administering to the subject an anti-human λ light chain antibody, or human λ light chain binding fragment thereof, described herein.

[0025] In some embodiments, the subject is suffering from a plasma cell disorder. In some embodiments, the plasma cell disorder comprises plasma cell dysplasia. In some embodiments, the plasma cell dysplasia is selected from monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma (MM), plasma cell leukemia (PCL), and any combination thereof. In some embodiments, the subject is suffering from systemic amyloidosis. In some embodiments, the subject is suffering from AL amyloidosis. [Brief explanation of the drawings]

[0026] The novel features of the invention within this composition disclosure are set forth with particularity in the appended claims. The features and advantages of the invention within this composition disclosure will be better understood by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings.

[0027] [Figure 1] (Figure 1 shows the detection of unfolded full-length lambda light chain protein by denaturing SDS-PAGE followed by denaturing Western blots probed with five mouse monoclonal antibodies described herein. Input samples included pooled kappa (κ) and lambda (λ) light chains from human myeloma sera, as well as lambda light chain amyloidosis patient serum (pt). Two of the five clones showed reactivity with both lambda and kappa sera. [Figure 2A]1 is a line graph illustrating the results of an indirect ELISA using five mouse monoclonal antibodies described herein to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 2B] 1 is a line graph illustrating the results of an indirect ELISA using five mouse monoclonal antibodies described herein to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 2C] 1 is a line graph illustrating the results of an indirect ELISA using five mouse monoclonal antibodies described herein to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 2D] 1 is a line graph illustrating the results of an indirect ELISA using five mouse monoclonal antibodies described herein to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 2E] 1 is a line graph illustrating the results of an indirect ELISA using five mouse monoclonal antibodies described herein to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 2F]1 is a line graph illustrating the results of an indirect ELISA using a commercially available control antibody ("Com") to detect native or misfolded forms of the lambda light chain (Wil). Various concentrations of native or misfolded Wil were bound and detected using the appropriate HRP-conjugated secondary antibody using TMB chemistry. [Figure 3] Images of native Western blots for misfolded, native, or amyloid species probed with five mouse monoclonal antibodies. Western blots were prepared by transfer from native PAGE and detection with the appropriate secondary antibodies. Native (n) or misfolded (m) Wil monomer species appear as bands of approximately 25 kDa, whereas aggregates (a) or large MW species (>250 kDa) appear as a smear in the amyloid (a) sample lane. [Figure 4A] Graphical representation of the results of a capture ELISA using misfolded (half-filled circles) or native (filled circles) Wil as the target for monoclonal antibody binding. For both clones, increasing the concentration of native Wil did not result in a significant change in signal, while a similar increase in the concentration of misfolded Wil resulted in increased binding. These binding curves correspond to affinities of 69 nM (clone 1) and 32 nM (clone 2). [Figure 4B] Graphical representation of the results of a capture ELISA using misfolded (half-filled circles) or native (filled circles) Wil as the target for monoclonal antibody binding. For both clones, increasing the concentration of native Wil did not result in a significant change in signal, while a similar increase in the concentration of misfolded Wil resulted in increased binding. These binding curves correspond to affinities of 69 nM (clone 1) and 32 nM (clone 2). [Figure 5A]Biolayer interferometry sensorgrams of the binding interaction between Clone 1 (Figure 5A) and Clone 2 (Figure 5B) for misfolded λ light chain Wil. Binding of Clone 1 and Clone 2 to their misfolded Wil over a range of target concentrations (1000 nM to 4 nM) was measured by wavelength (nM) change over 500 seconds (120 seconds association, 300 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine KD. [Figure 5B] Biolayer interferometry sensorgrams of the binding interaction between Clone 1 (Figure 5A) and Clone 2 (Figure 5B) for misfolded λ light chain Wil. Binding of Clone 1 and Clone 2 to their misfolded Wil over a range of target concentrations (1000 nM to 4 nM) was measured by wavelength (nM) change over 500 seconds (120 seconds association, 300 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine KD. [Figure 6A] Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the misfolded conformation of the lambda light chain variant of Wil. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 6B] Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the misfolded conformation of the H3 lambda light chain variant. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 6C]Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the misfolded conformation of the lambda light chain variant of FOR102. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 6D] Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the native conformation of the lambda light chain variant of Wil. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 6E] Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the native conformation of the lambda light chain variant of H3. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 6F] Biolayer interferometry sensorgram of the binding interaction between clone 1 (muLX-97) and the native conformation of the lambda light chain variant of FOR102. Binding of muLX-97 to its misfolded Wil over a range of target concentrations was measured by wavelength (nM) shift over 720 seconds (120 seconds association, 600 seconds dissociation). Association and dissociation curves were fitted using Octet Systems software to determine the KD. [Figure 7A]1 is a line graph illustrating the binding of misfolded Wil with muLX-97 as measured by MST (microscale thermophoresis). The shift in normalized relative fluorescence (Fnorm) during thermophoresis as a function of ligand concentration shows a transition corresponding to a KD of 61.9 nM for misfolded Wil and 87 nM for amyloid Wil. [Figure 7B] 1 is a line graph illustrating the binding of amyloid Wil to muLX-97 as measured by MST (microscale thermophoresis). The shift in normalized relative fluorescence (Fnorm) during thermophoresis as a function of ligand concentration shows a transition corresponding to a KD of 61.9 nM for misfolded Wil and 87 nM for amyloid Wil. [Figure 8A] Immunohistochemical staining and fluorescent images of a biopsy-confirmed case of λAL amyloidosis. The gastrointestinal case was stained with muLX-97 (dark areas). Scale bar = 100 μm. [Figure 8B] Immunohistochemical staining and fluorescent images of a biopsy-confirmed case of λAL amyloidosis. The soft tissue case was stained with muLX-97 (dark areas). Scale bar = 100 μm. [Figure 8C] Immunohistochemical staining and fluorescent images of a biopsy-confirmed case of λAL amyloidosis. The gastrointestinal case was co-stained with Congo Red amyloid-specific dye to visualize the fluorescent signal (white area). Scale bar = 100 μm. [Figure 8D] Immunohistochemical staining and fluorescent images of a biopsy-confirmed case of λAL amyloidosis. The soft tissue case was co-stained with Congo Red amyloid-specific dye to visualize the fluorescent signal (white area). Scale bar = 100 μm. [Figure 9A] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Gastrointestinal cases of λAL amyloidosis stained positive (dark areas). Scale bar = 100 μm. [Figure 9B]Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Gastrointestinal cases of λAL amyloidosis stained positive (dark areas). Scale bar = 100 μm. [Figure 9C] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Kidney cases of λAL amyloidosis stained positive (dark areas). Scale bar = 100 μm. [Figure 9D] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Soft tissue cases of λAL amyloidosis stained positive (dark areas). Scale bar = 100 μm. [Figure 9E] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Soft tissue cases of λAL amyloidosis stained positive (dark areas). Scale bar = 100 μm. [Figure 9F] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Pathological controls of IAPP amyloid pancreatic tissue stained were negative. Scale bar = 100 μm. [Figure 9G] Immunohistochemical staining images of biopsy-confirmed cases of λAL amyloidosis or pathological controls stained with muLX-97. Pathological controls of ATTR cardiac amyloid tissue stained negative. Scale bar = 100 μm. [Figure 10A] Fluorescence images of RAW264.7 cells in a field representation. Cells were incubated with pHrodo-labeled Wil for 30 minutes in the presence of various concentrations of isotype control antibody. The pHrodo fluorescent signal (white) represents cells that have internalized Wil amyloid by phagocytic uptake. Scale bar = 100 μm. [Figure 10B] Fluorescence images of RAW264.7 cells in a field representation. Cells were incubated with pHrodo-labeled Wil for 30 minutes in the presence of various concentrations of muLX-97. The pHrodo fluorescent signal (white) represents cells that have internalized Wil amyloid by phagocytic uptake. Scale bar = 100 μm. [Figure 11A] Fluorescence images of J774.1 cells in a field representation. Cells were incubated with pHrodo-labeled Wil for 30 minutes in the presence of various concentrations of isotype control antibody. The pHrodo fluorescent signal (white) represents cells that have internalized Wil amyloid by phagocytic uptake. Scale bar = 100 μm. [Figure 11B] Fluorescence images of J774.1 cells in a field representation. Cells were incubated with pHrodo-labeled Wil for 30 minutes in the presence of various concentrations of muLX-97. The pHrodo fluorescent signal (white) represents cells that have internalized Wil amyloid by phagocytic uptake. Scale bar = 100 μm. [Figure 12A] This is a line graph showing the dose-dependent phagocytic uptake of pHrodo-labeled amyloid Wil induced by muLX-97 in mouse macrophage cells. 40,000 RAW264.7 cells were incubated with pHrodo-labeled Wil and either isotype antibody (circles) or muLX-97 (triangles) with increasing antibody concentrations. Cells with pHrodo fluorescence were imaged (white) and quantified using a Biotek Cytation 5 imager. Total cell counts were performed using the nuclear stain Nuc Blue live cell reagent to determine the % pHrodo positivity. A plot of the % pHrodo-positive cells as a function of muLX-97 concentration shows a transition corresponding to an EC50 of 20 nM for RAW264.7 cells and 7 nM for J774.1 cells. [Figure 12B]This is a line graph showing the dose-dependent phagocytic uptake of pHrodo-labeled amyloid Wil induced by muLX-97 in mouse macrophage cells. 40,000 J774.1 cells were incubated with pHrodo-labeled Wil and either isotype antibody (circles) or muLX-97 (triangles) at increasing antibody concentrations. Cells with pHrodo fluorescence were imaged (white) and quantified using a Biotek Cytation 5 imager. Total cell counts were performed using the nuclear stain Nuc Blue live cell reagent to determine the % pHrodo positivity. A plot of the % pHrodo-positive cells as a function of muLX-97 concentration shows a transition corresponding to an EC50 of 20 nM for RAW264.7 cells and 7 nM for J774.1 cells. DETAILED DESCRIPTION OF THE INVENTION

[0028] Current treatments for AL amyloidosis are designed to treat the underlying plasma cell dysplasia (i.e., multiple myeloma) by targeting the cells that produce toxic light chains. The only currently available on-label therapy is the monoclonal antibody-based therapy daratumumab and hyaluronidase-fihj in combination with bortezomib, cyclophosphamide, and dexamethasone. This antibody (and other off-label therapies) induces antibody-dependent cellular cytotoxicity by targeting the CD38 receptor on plasma cells. While the initial indication for this drug was multiple myeloma, it was approved as an on-label treatment for newly diagnosed patients with AL amyloidosis in January 2021. Other treatments for AL amyloidosis include more invasive interventions such as autologous stem cell transplantation (ASTC) or standard cytotoxic chemotherapy. However, all of the aforementioned treatments work by targeting the proliferation of disease-causing plasma cell clones, but do not address the amyloid deposits that already exist and directly affect organs. Daratumumab is also effective in early-stage patients, but is not recommended for patients with late-stage heart disease. Therefore, non-invasive therapies that do not deplete plasma cell populations to address existing toxic amyloid deposits and improve organ function in late-stage patients remain a significant challenge and unmet need in the treatment of disorders characterized by AL amyloidosis and / or misfolded antibody molecules.

[0029] Anti-human gamma light chain antibody Provided herein are antibodies and antibody fragments that bind to human λ light chains. The anti-human λ light chain antibodies described herein are useful and advantageous in that the antibodies and antibody fragments specifically bind to misfolded λ light chains (i.e., compared to folded light chains). Generally, these usefulness and advantages can be attributed to the ability of the anti-human λ light chain antibodies to specifically bind to SEQ ID NO: 51, an epitope specific to misfolded λ light chains. In certain examples, the antibodies provided herein are anti-human λ light chain antibodies that promote the clearance of misfolded λ light chains (e.g., those present in AL amyloidosis or plasma cell dyscrasias). In some embodiments, the anti-human λ light chain antibodies are useful in methods for reducing amyloid deposition and / or treating diseases characterized by amyloid deposits (e.g., those present in AL amyloidosis or plasma cell dyscrasias). In other examples, the anti-human λ light chain antibodies can be used to diagnose, detect, or screen for misfolded λ light chains, amyloid deposits, and / or disorders related thereto.

[0030] Anti-human gamma light chain CDR In this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 3; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 4; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 5; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 6; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 7, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 8 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 1, and / or a light chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 2. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0031] In addition, in this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 13; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 14; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 15; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 16; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 17, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 18 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 11, and / or a light chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 12. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0032] Further, in this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 23; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 24; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 25; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 26; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 27, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 28 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 21, and / or a light chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 22. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0033] In this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 33; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 34; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 35; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 36; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 37, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 38 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 31, and / or a light chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 32. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0034] Further, in this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 43; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 44; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 45; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 46; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 47, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 48 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 41, and / or a light chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 42. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0035] Further, in this specification, (a) a heavy chain complementarity-determining region 1 (H-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 33 or 43; (b) a heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 34 or 44; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 35 or 45; (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence set forth in SEQ ID NO: 36 or 46; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence set forth in SEQ ID NO: 37 or 47, and / or (f) a light chain complementarity-determining region 3 (L-CDR3) comprising the amino acid sequence set forth in SEQ ID NO: 38 or 48 wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 31 or 41, and / or the light chain variable region comprises an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 32 or 42. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0036] In addition, in this specification, (a) heavy chain complementarity determining region 1 (H-CDR1) comprising the amino acid sequence NFGMH; (b) heavy chain complementarity-determining region 2 (H-CDR2) comprising the amino acid sequence WMNTYTGESTYAD(D or E)FKG; (c) a heavy chain complementarity-determining region 3 (H-CDR3) comprising the amino acid sequence ISYDYDGYTMD (F or Y); (d) a light chain complementarity-determining region 1 (L-CDR1) comprising the amino acid sequence RS(G or S)QSLVH(R or S)NGNTY(F or L)H; (e) a light chain complementarity-determining region 2 (L-CDR2) comprising the amino acid sequence K(V or L)SI(R or N)FS, and / or (f) light chain complementarity-determining region 3 (L-CDR3) containing the amino acid sequence SQSTHVPWT wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment comprises a heavy chain variable region comprising an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 31 or 41, and / or the light chain variable region comprises an amino acid sequence having at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% identity to SEQ ID NO: 32 or 42. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51.

[0037] In this specification, (a) heavy chain complementarity determining region 1 (H-CDR1); (b) heavy chain complementarity determining region 2 (H-CDR2); (c) heavy chain complementarity determining region 3 (H-CDR3); (d) light chain complementarity determining region 1 (L-CDR1); (e) light chain complementarity-determining region 2 (L-CDR2), and / or (f) light chain complementarity-determining region 3 (L-CDR3) wherein H-CDR1, H-CDR2, and H-CDR3 are derived from SEQ ID NO: 1, and L-CDR1, L-CDR2, and L-CDR3 are derived from SEQ ID NO: 2, and wherein H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using the Chothia, Kabat, IMGT, Contact, or AbM method. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Chothia. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Kabat. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using IMGT. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Contact. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using AbM.

[0038] In this specification, (a) heavy chain complementarity determining region 1 (H-CDR1); (b) heavy chain complementarity determining region 2 (H-CDR2); (c) heavy chain complementarity determining region 3 (H-CDR3); (d) light chain complementarity determining region 1 (L-CDR1); (e) light chain complementarity-determining region 2 (L-CDR2), and / or (f) light chain complementarity-determining region 3 (L-CDR3) wherein H-CDR1, H-CDR2, and H-CDR3 are derived from SEQ ID NO: 11, and L-CDR1, L-CDR2, and L-CDR3 are derived from SEQ ID NO: 12, and wherein H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using the Chothia, Kabat, IMGT, Contact, or AbM method. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Chothia. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Kabat. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using IMGT. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Contact. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using AbM.

[0039] In this specification, (a) heavy chain complementarity determining region 1 (H-CDR1); (b) heavy chain complementarity determining region 2 (H-CDR2); (c) heavy chain complementarity determining region 3 (H-CDR3); (d) light chain complementarity determining region 1 (L-CDR1); (e) light chain complementarity-determining region 2 (L-CDR2), and / or (f) light chain complementarity-determining region 3 (L-CDR3) wherein H-CDR1, H-CDR2, and H-CDR3 are derived from SEQ ID NO: 21, and L-CDR1, L-CDR2, and L-CDR3 are derived from SEQ ID NO: 22, and wherein H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using the Chothia, Kabat, IMGT, Contact, or AbM method. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Chothia. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Kabat. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using IMGT. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Contact. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using AbM.

[0040] In this specification, (a) heavy chain complementarity determining region 1 (H-CDR1); (b) heavy chain complementarity determining region 2 (H-CDR2); (c) heavy chain complementarity determining region 3 (H-CDR3); (d) light chain complementarity determining region 1 (L-CDR1); (e) light chain complementarity-determining region 2 (L-CDR2), and / or (f) light chain complementarity-determining region 3 (L-CDR3) wherein H-CDR1, H-CDR2, and H-CDR3 are derived from SEQ ID NO: 31, and L-CDR1, L-CDR2, and L-CDR3 are derived from SEQ ID NO: 32, and wherein H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using the Chothia, Kabat, IMGT, Contact, or AbM method. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Chothia. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Kabat. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using IMGT. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Contact. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using AbM.

[0041] In this specification, (a) heavy chain complementarity determining region 1 (H-CDR1); (b) heavy chain complementarity determining region 2 (H-CDR2); (c) heavy chain complementarity determining region 3 (H-CDR3); (d) light chain complementarity determining region 1 (L-CDR1); (e) light chain complementarity-determining region 2 (L-CDR2), and / or (f) light chain complementarity-determining region 3 (L-CDR3)

[0013] Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain binding antibody fragments comprising:

[0042] H-CDR1, H-CDR2, and H-CDR3 are derived from SEQ ID NO: 41, and L-CDR1, L-CDR2, and L-CDR3 are derived from SEQ ID NO: 42, and H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using the Chothia, Kabat, IMGT, Contact, or AbM method. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Chothia. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Kabat. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using IMGT. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using Contact. In some embodiments, H-CDR1, H-CDR2, H-CDR3, L-CDR1, L-CDR2, and L-CDR3 are defined using AbM.

[0043] In some embodiments, the anti-human λ light chain antibody and / or human λ light chain binding antibody fragment binds to an epitope comprising SEQ ID NO: 1. In certain embodiments, the anti-human λ light chain antibody and / or human λ light chain binding antibody fragment binds to an epitope consisting of SEQ ID NO: 1. In certain embodiments, binding is measured by ELISA, surface plasmon resonance, biolayer interferometry, or isothermal calorimetry.

[0044] In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment further comprises heavy chain framework region 1 (H-FR1), heavy chain framework region 2 (H-FR2), heavy chain framework region 3 (H-FR3), and heavy chain framework region 4 (H-FR4), as well as light chain framework region 1 (L-FR1), light chain framework region 2 (L-FR2), light chain framework region 3 (L-FR3), and light chain framework region 4 (L-FR4). In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment further comprises a heavy chain variable region and a light chain variable region. In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment further comprises a heavy chain constant region and a light chain constant region.

[0045] Anti-human gamma light chain variable region In this specification, a heavy chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 1, and / or a light chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO:2; Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO:51 (e.g., as measured by ELISA). In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:1, and the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO:2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO:1, and the light chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO:2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO:1, and the light chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO:2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 1, and the light chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 1, and the light chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 1, and the light chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 2. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 1, and the light chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 2.

[0046] In addition, in this specification, a heavy chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 11, and / or a light chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 12 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51 (e.g., as measured by ELISA). In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 12. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 11, and the light chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 12.

[0047] In this specification, a heavy chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 21, and / or a light chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 22 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51 (e.g., as measured by ELISA). In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 1, and the light chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 22. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 21, and the light chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 22.

[0048] In this specification, a heavy chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 31, and / or a light chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 32 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51 (e.g., as measured by ELISA). In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 32. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 31, and the light chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 32.

[0049] In this specification, a heavy chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 41, and / or a light chain variable region comprising an amino acid sequence having at least about 70% identity to SEQ ID NO: 42 Provided and described are anti-human gamma light chain antibodies and / or human gamma light chain-binding antibody fragments comprising: wherein the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment binds to an epitope comprising SEQ ID NO: 51 (e.g., as measured by ELISA). In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 80% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 85% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 90% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 95% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 97% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 98% identity to SEQ ID NO: 42. In some embodiments, the heavy chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 41, and the light chain variable region comprises an amino acid sequence having at least about 99% identity to SEQ ID NO: 42.

[0050] Anti-human gamma light chain constant region In some embodiments, anti-human λ light chain antibodies include intact or full-length antibodies, including antibodies of any class or subclass, including IgG and its subclasses IgM, IgE, IgA, and IgD. In certain embodiments, anti-human λ light chain antibodies comprise a human IgG constant region. In certain embodiments, anti-human λ light chain antibodies comprise a human IgG1 constant region. In certain embodiments, anti-human λ light chain antibodies comprise a human IgG2 constant region. In certain embodiments, anti-human λ light chain antibodies comprise a human IgG3 constant region. In certain embodiments, anti-human λ light chain antibodies comprise a human IgG4 constant region. In some embodiments, anti-human λ light chain antibodies comprise a heavy chain sequence comprising at least 85% sequence identity to SEQ ID NO: 52. In some embodiments, anti-human λ light chain antibodies comprise a heavy chain sequence comprising at least 90% sequence identity to SEQ ID NO: 52. In some embodiments, anti-human λ light chain antibodies comprise a heavy chain sequence comprising at least 95% sequence identity to SEQ ID NO: 52. In some embodiments, the anti-human λ light chain antibody comprises a heavy chain sequence comprising at least 98% sequence identity to SEQ ID NO: 52. In some embodiments, the anti-human λ light chain antibody comprises a heavy chain sequence comprising at least 99% sequence identity to SEQ ID NO: 52. In some embodiments, the anti-human λ light chain antibody comprises a heavy chain sequence comprising SEQ ID NO: 52.

[0051] In certain embodiments, the present specification describes an antibody that binds to misfolded human λ light chains. In certain embodiments, the antibody binds to aggregated human λ light chains. In certain embodiments, the antibody binds to amyloid human λ light chains. In certain embodiments, the antibody has a K of less than about 100 nanomolar. D In certain embodiments, the antibody binds to aggregated human λ light chains with a K of less than about 90 nanomolar. D In certain embodiments, the antibody binds to aggregated human λ light chains with a K of less than about 80 nanomolar. D In certain embodiments, the antibody binds to aggregated human λ light chains with a K of greater than about 1, 10, 20, 30, 40, or 50 nanomolar. DIn certain embodiments, the antibody binds to aggregated human λ light chains with a K of less than about 100 nanomolar. D In certain embodiments, the antibody binds to amyloid human λ light chains with a K of less than about 90 nanomolar. D In certain embodiments, the antibody binds to amyloid human lambda light chains with a K of less than about 80 nanomolar. D In certain embodiments, the antibody binds to amyloid human λ light chains with a K of less than about 70 nanomolar. D In certain embodiments, the antibody binds to amyloid human λ light chains with a K of greater than about 1, 10, 20, 30, 40, or 50 nanomolar. D and binds to amyloid human lambda light chains.

[0052] composition Provided herein are compositions (e.g., pharmaceutical compositions) comprising the anti-human λ light chain antibodies and / or human λ light chain-binding antibody fragments described herein. A composition or pharmaceutical formulation or pharmaceutical composition generally encompasses and / or refers to a preparation that is in a form that allows the biological activity of the active ingredient contained therein to be effective and does not contain additional ingredients that are unacceptably toxic to the subject to which the formulation is administered. Pharmaceutical formulations are generally sterile (e.g., aseptic or free from all viable microorganisms and their spores).

[0053] Compositions comprising the anti-human λ light chain antibodies and / or human λ light chain-binding antibody fragments described herein can be included in pharmaceutical compositions containing one or more pharmaceutically acceptable excipients, carriers, and diluents. In certain embodiments, the antibodies of the present disclosure are administered suspended in a sterile and / or isotonic solution. In certain embodiments, the solution contains about 0.9% NaCl. In certain embodiments, the solution contains about 5.0% dextrose. In certain embodiments, the solution further comprises one or more of a buffer, e.g., acetate, citrate, histidine, succinate, phosphate, bicarbonate, and hydroxymethylaminomethane (Tris); a surfactant, e.g., polysorbate 80 (Tween 80), polysorbate 20 (Tween 20), and poloxamer 188; a polyol / disaccharide / polysaccharide, e.g., glucose, dextrose, mannose, mannitol, sorbitol, sucrose, L-histidine / L-histidine monohydrochloride monohydrate, trehalose, and dextran 40; an amino acid, e.g., glycine or arginine; an antioxidant, e.g., ascorbic acid, methionine; or a chelating agent, e.g., EDTA or EGTA.

[0054] Formulations for antibody administration can include one or more of the following: a buffer, such as acetate, citrate, histidine, succinate, phosphate, bicarbonate, and hydroxymethylaminomethane (Tris); a surfactant, such as polysorbate 80 (Tween 80), polysorbate 20 (Tween 20), and poloxamer 188; a polyol / disaccharide / polysaccharide, such as glucose, dextrose, mannose, mannitol, sorbitol, sucrose, trehalose, and dextran 40; an amino acid, such as glycine or arginine; an antioxidant, such as ascorbic acid or methionine; or a chelating agent, such as EDTA or EGTA. Additionally, a compound or molecule that reduces pain at the injection site, such as hyaluronidase, can be included, for example, at a concentration of about 2,000 U / ml to about 12,000 U / ml.

[0055] In certain embodiments, the anti-human gamma light chain antibodies or human gamma light chain-binding antibody fragments described herein are shipped / stored lyophilized and reconstituted prior to administration. In certain embodiments, the lyophilized antibody formulation contains a bulking agent such as mannitol, sorbitol, sucrose, trehalose, dextran 40, or a combination thereof. The lyophilized formulation can be contained in a vial made of glass or other suitable non-reactive material. When formulated, the antibody, whether reconstituted or not, can be buffered at a specific pH, generally below 7.0. In certain embodiments, the pH can be 4.5-6.5, 4.5-6.0, 4.5-5.5, 4.5-5.0, or 5.0-6.0.

[0056] In some embodiments, the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment is configured for intravenous, intramuscular, intra-arterial, intrathecal, intralymphatic, intralesional, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intra-articular, subcapsular, subarachnoid, intraspinal, epidural, or intrasternal injection. In some embodiments, the composition comprising the anti-human λ light chain antibody and / or human λ light chain-binding antibody fragment is configured for intravenous injection.

[0057] Also described herein are kits comprising one or more of the antibodies described herein in a suitable container and one or more additional components selected from instructions for use, diluents, excipients, carriers, and devices for administration.

[0058] In certain embodiments, described herein are methods for preparing a treatment comprising mixing one or more pharmaceutically acceptable excipients, carriers, or diluents with an anti-human λ light chain antibody and / or a human λ light chain-binding antibody fragment. In certain embodiments, described herein are methods for preparing a cancer treatment for storage or transportation comprising lyophilizing one or more antibodies of the present disclosure.

[0059] Host Cells and Nucleic Acids Host cell, host cell line, and / or host cell culture are used interchangeably and generally include and / or refer to cells into which exogenous nucleic acid has been introduced, including their progeny. Host cells include transformants and transformed cells, which include the primary transformed cell and its progeny without regard to the number of transfers.

[0060] An isolated nucleic acid generally encompasses and / or refers to a nucleic acid molecule that has been separated from a component of its natural environment. An isolated nucleic acid encompasses a nucleic acid molecule contained in a cell that normally contains the nucleic acid molecule, but where the nucleic acid molecule is present extrachromosomally or at a chromosomal location that is different from its natural chromosomal location. An isolated nucleic acid encoding an antibody encompasses and / or refers to one or more nucleic acid molecules encoding antibody heavy and light chains (or fragments thereof), including such nucleic acid molecules in a single vector or separate vectors, and such nucleic acid molecules present at one or more locations in a host cell. In some embodiments, provided herein are nucleic acid sequences encoding anti-human λ light chain antibodies and / or human λ light chain-binding antibody fragments described herein. In some embodiments, also provided herein are host cells containing nucleic acid sequences encoding anti-human λ light chain antibodies and / or human λ light chain-binding antibody fragments. In some embodiments, a nucleic acid sequence encoding an anti-human λ light chain antibody and / or a human λ light chain binding antibody fragment comprises at least 60% sequence identity to any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50. In some embodiments, a nucleic acid sequence encoding an anti-human λ light chain antibody and / or a human λ light chain binding antibody fragment comprises at least 70% sequence identity to any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50. In some embodiments, a nucleic acid sequence encoding an anti-human λ light chain antibody and / or a human λ light chain binding antibody fragment comprises at least 80% sequence identity to any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50. In some embodiments, a nucleic acid sequence encoding an anti-human λ light chain antibody and / or a human λ light chain binding antibody fragment comprises at least 90% sequence identity to any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50. In some embodiments, a nucleic acid sequence encoding an anti-human λ light chain antibody and / or a human λ light chain binding antibody fragment comprises at least 95% sequence identity to any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50.In some embodiments, the nucleic acid sequence encoding the anti-human λ light chain antibody and / or human λ light chain binding antibody fragment comprises any one of SEQ ID NOs: 9-10, 19-20, 29-30, 39-40, or 49-50.

[0061] method The anti-human λ light chain antibodies and / or human λ light chain binding antibody fragments described herein can be used to identify, detect, and treat misfolded light chains (e.g., λ light chain aggregates or amyloid deposits) and diseases or disorders associated therewith.

[0062] Methods for detecting light chains Provided and described herein are methods for diagnosing amyloidosis in a sample, comprising contacting a biological sample obtained from a subject with an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. Also provided herein are methods for detecting free light chain polypeptides in a sample, comprising contacting a biological sample with an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. Further provided herein are methods for diagnosing amyloid deposits in a sample, comprising contacting a biological sample with an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. In some embodiments, the sample is derived from blood, serum, plasma, solid tissue, and any combination thereof. In some embodiments, the sample is derived from a subject.

[0063] As described, certain embodiments of the present disclosure relate to methods for measuring light chain immunoglobulins. The anti-human λ light chain antibodies or human λ light chain-binding antibody fragments disclosed herein can be used to measure any immunoglobulin light chain or aggregates thereof. In some embodiments, the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments are used to measure immunoglobulin light chains or aggregates thereof in vivo. In some embodiments, the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments are used to measure immunoglobulin light chains or aggregates thereof in a biological sample collected from a subject. In some embodiments, the biological sample is a plasma sample, a blood sample, a tissue sample (e.g., a tissue biopsy), a urine sample, or any combination thereof.

[0064] In some embodiments, the methods include measuring light chain fibrils. Thus, the antibodies described herein can be used to identify subjects with a disease or disorder characterized by the formation of immunoglobulin light chain deposits, e.g., amyloid fibril deposits. In some embodiments, an anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify (e.g., diagnose) a subject with amyloidosis. In some embodiments, an anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject with systemic amyloidosis. In some embodiments, an anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject with AL amyloidosis. In some embodiments, an anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject with plasma cell dysplasia. In some embodiments, an anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject with monoclonal gammopathy of undetermined significance (MGUS). In some embodiments, the anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject as having multiple myeloma (MM). In some embodiments, the anti-human λ light chain antibody or human λ light chain-binding antibody fragment is used to identify a subject as having plasma cell leukemia (PCL).

[0065] In some embodiments, the anti-human λ light chain antibody or human λ light chain-binding antibody fragment comprises one or more labels, covalently or non-covalently bound antibodies, or antigen-binding fragments. Any label known in the art can be used to increase the ability of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment to be detected and / or visualized. In some embodiments, the label comprises a chemical label. In some embodiments, the label comprises an enzymatic label. In some embodiments, the label comprises a substrate that is detectable in the presence of a specific enzyme. In some embodiments, the label is a fluorescent label. In some embodiments, the label is a radioisotope label.

[0066] Certain embodiments of the present disclosure relate to methods for measuring light chain immunoglobulins in vivo using the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments disclosed herein. In some embodiments, the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments comprise a detectable probe. In some embodiments, the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments are contrast agent-conjugated antibodies. In some embodiments, the method is a diagnostic medical imaging method, such as PET / CT, SPECT, MRI, or any combination thereof.

[0067] Methods for treating and / or reducing misfolded gamma light chains Provided and described herein are methods for promoting the clearance of λ light chain aggregates by monocytes, comprising contacting λ light chain aggregates with an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. Also provided and described are methods for increasing the clearance of λ light chain aggregates, comprising contacting λ light chain aggregates with an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. Also provided and described are methods for reducing λ light chain aggregates in a subject, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, thereby reducing the number of λ light chain aggregates in the subject. Also provided and described are methods for treating a disease or disorder characterized by λ light chain aggregates, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, thereby reducing the number of λ light chain aggregates in the subject. Provided and described are methods for treating AL amyloidosis (e.g., in a subject having λ light chain aggregates), comprising reducing the number of λ light chain aggregates in the subject by administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein.

[0068] In some embodiments, the subject has a plasma cell disorder. In some embodiments, the plasma cell disorder comprises plasma cell dysplasia. In some embodiments, the plasma cell dysplasia is selected from monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma (MM), plasma cell leukemia (PCL), and any combination thereof. In certain embodiments, the subject is a human.

[0069] Certain uses of the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments described herein relate to methods of treating a disease or condition in a subject in need thereof, the method comprising administering an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. In some embodiments, the disease or condition comprises amyloidosis. In some embodiments, the disease or condition comprises systemic amyloidosis. In some embodiments, the disease or condition comprises AL amyloidosis. In some embodiments, the disease or condition comprises plasma cell dysplasia. In some embodiments, the disease or condition comprises monoclonal gammopathy of undetermined significance (MGUS). In some embodiments, the disease or condition comprises multiple myeloma (MM). In some embodiments, the disease or condition comprises plasma cell leukemia (PCL).

[0070] Certain uses of the anti-human λ light chain antibodies or human λ light chain-binding antibody fragments described herein relate to methods for reducing and / or removing immunoglobulin light chain aggregates, e.g., amyloid fibrils, in a subject in need thereof, the method comprising administering an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein. In some embodiments, the subject has one or more immunoglobulin light chain aggregates, e.g., amyloid fibrils, in the heart. In some embodiments, the subject has one or more immunoglobulin light chain aggregates, e.g., amyloid fibrils, in the kidney. In some embodiments, the subject has one or more immunoglobulin light chain aggregates, e.g., amyloid fibrils, in tissues of the nervous system. In some embodiments, the subject has one or more immunoglobulin light chain aggregates, e.g., amyloid fibrils, in the brain.

[0071] Certain uses of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein relate to a method of treating nephrotic syndrome in a subject in need thereof, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, wherein the nephrotic syndrome comprises one or more immunoglobulin light chain deposits, e.g., one or more amyloid fibril deposits. Certain uses of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein relate to a method of treating hepatomegaly in a subject in need thereof, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, wherein the hepatomegaly comprises one or more immunoglobulin light chain deposits, e.g., one or more amyloid fibril deposits. Certain uses of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein relate to a method of treating peripheral neuropathy in a subject in need thereof, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, wherein the peripheral neuropathy comprises one or more immunoglobulin light chain deposits, e.g., one or more amyloid fibril deposits. Certain uses of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein relate to a method of treating restrictive cardiomyopathy in a subject in need thereof, comprising administering to the subject an anti-human λ light chain antibody or human λ light chain-binding antibody fragment described herein, wherein the restrictive cardiomyopathy comprises one or more immunoglobulin light chain deposits, e.g., one or more amyloid fibril deposits.

[0072] In some embodiments, administration of an anti-human λ light chain antibody or human λ light chain-binding antibody fragment to a subject results in the reduction and / or clearance of one or more immunoglobulin light chain aggregates, e.g., amyloid fibrils, in the subject. In some embodiments, the size of immunoglobulin light chain aggregates, e.g., amyloid fibrils, in the subject is reduced after administration of the anti-human λ light chain antibody or human λ light chain-binding antibody fragment.

[0073] In certain embodiments, the antibody can be administered to a subject in need of the antibody by any route suitable for administering an antibody-containing pharmaceutical composition, such as subcutaneously, intraperitoneally, intravenously, or intramuscularly. In certain embodiments, the antibody is administered intravenously. In certain embodiments, the antibody is administered subcutaneously. In certain embodiments, the antibody is administered on a suitable dosing schedule, such as weekly, twice weekly, monthly, twice monthly, once every two weeks, once every three weeks, or once monthly. In certain embodiments, the antibody is administered once every three weeks. The antibody can be administered in any therapeutically effective amount. In certain embodiments, a therapeutically acceptable amount is from about 0.1 mg / kg to about 50 mg / kg. In certain embodiments, a therapeutically acceptable amount is from about 1 mg / kg to about 40 mg / kg. In certain embodiments, a therapeutically acceptable amount is from about 1 mg / kg to about 20 mg / kg. In certain embodiments, a therapeutically acceptable amount is from about 1 mg / kg to about 10 mg / kg. In certain embodiments, a therapeutically acceptable amount is from about 5 mg / kg to about 30 mg / kg. In certain embodiments, a therapeutically acceptable amount is from about 5 mg / kg to about 20 mg / kg. A therapeutically effective amount includes an amount sufficient to alleviate one or more symptoms associated with the disease or affliction being treated.

[0074] Pharmaceutically Acceptable Excipients, Carriers, and Diluents In certain embodiments, the anti-λ light chain antibody of the present disclosure is contained in a pharmaceutical composition comprising one or more pharmaceutically acceptable excipients, carriers, and diluents. Pharmaceutically acceptable excipients, carriers, and diluents can be included to increase the shelf life, stability, or administrability of the antibody. Such compounds include salts, pH buffers, detergents, anticoagulants, and preservatives. In certain embodiments, the antibody of the present disclosure is administered suspended in a sterile solution. In certain embodiments, the solution comprises about 0.9% NaCl. In certain embodiments, the solution comprises about 5.0% dextrose. In certain embodiments, the solution further comprises one or more of a buffer, e.g., acetate, citrate, histidine, succinate, phosphate, bicarbonate, and hydroxymethylaminomethane (Tris); a surfactant, e.g., polysorbate 80 (Tween 80), polysorbate 20 (Tween 20), and poloxamer 188; a polyol / disaccharide / polysaccharide, e.g., glucose, dextrose, mannose, mannitol, sorbitol, sucrose, trehalose, and dextran 40; an amino acid, e.g., glycine or arginine; an antioxidant, e.g., ascorbic acid, methionine; or a chelating agent, e.g., EDTA or EGTA.

[0075] In certain embodiments, antibodies of the present disclosure can be shipped / stored lyophilized and reconstituted prior to administration. In certain embodiments, lyophilized antibody formulations include bulking agents such as mannitol, sorbitol, sucrose, trehalose, dextran 40, or combinations thereof. Lyophilized formulations can be contained in vials made of glass or other suitable non-reactive materials. When formulated, antibodies, whether reconstituted or not, can be buffered at a specific pH, generally below 7.0. In certain embodiments, the pH can be 4.5-7.0, 4.5-6.5, 4.5-6.0, 4.5-5.5, 4.5-5.0, or 5.0-6.0.

[0076] Also described herein are kits comprising one or more of the antibodies described herein in a suitable container and one or more additional components selected from instructions for use, diluents, excipients, carriers, and devices for administration.

[0077] In certain embodiments, described herein are methods for preparing a lambda light chain amyloidosis therapeutic comprising mixing an antibody of the present disclosure with one or more pharmaceutically acceptable excipients, carriers, or diluents. In certain embodiments, described herein are methods for preparing a cancer therapeutic for storage or transportation comprising lyophilizing one or more antibodies of the present disclosure.

[0078] definition Antibody is used in the broadest sense and generally encompasses and / or refers to a variety of antibody structures, including, but not limited to, monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments, so long as they exhibit the desired antigen-binding activity. In some embodiments, antibodies include intact antibodies and functional (antigen-binding) antibody fragments, including fragment antigen-binding (Fab) fragments, F(ab')2 fragments, Fab' fragments, Fv fragments, recombinant IgG (rIgG) fragments, single-chain antibody fragments, including single-chain variable fragments (sFv or scFv), and single-domain antibody (e.g., sdAb, sdFv, nanobody) fragments. In some embodiments, antibodies include intrabodies, peptibodies, chimeric antibodies, fully human antibodies, humanized antibodies, and heteroconjugate antibodies, multispecific, e.g., bispecific, diabodies, triabodies, and tetrabodies, tandem di-scFv, tandem tri-scFv, and other engineered and / or otherwise modified forms of immunoglobulins. In some embodiments, antibodies include functional antibody fragments. In some embodiments, antibodies include intact or full-length antibodies, including antibodies of any class or subclass, including IgG and its subclasses, IgM, IgE, IgA, and IgD. Antibodies can include a human IgG1 constant region. Antibodies can include a human IgG4 constant region. In some embodiments, antibodies include full-length and native antibodies, as well as fragments and portions thereof that retain binding specificity, e.g., any specific binding portion thereof, including those having any number of immunoglobulin classes and / or isotypes (e.g., IgG1, IgG2, IgG3, IgG4, IgM, IgA, IgD, IgE, and IgM), and biologically relevant (antigen-binding) fragments or specific binding portions thereof, including, but not limited to, Fab, F(ab'), Fv, and scFv (single chain or related entities). Monoclonal antibodies are generally within a substantially homogeneous composition of antibodies. Hence, all individual antibodies contained within a monoclonal antibody composition are identical except for possible naturally occurring mutations that may be present in small amounts within the composition.The monoclonal antibody can comprise a human IgG1 constant region or a human IgG4 constant region.

[0079] Native antibodies generally encompass and / or refer to naturally occurring immunoglobulin molecules with various structures. For example, native IgG antibodies are heterotetrameric glycoproteins of approximately 150,000 daltons, composed of two identical disulfide-bonded light chains and two identical heavy chains. From the N-terminus to the C-terminus, each heavy chain has a variable region (VH), also called a variable heavy domain or heavy chain variable domain, followed by three constant domains (CH1, CH2, and CH3). Similarly, from the N-terminus to the C-terminus, each light chain has a variable region (VL), also called a variable light domain or light chain variable domain, followed by a constant light chain (CL) domain. Based on the amino acid sequence of its constant domain, the light chain of an antibody can be assigned to one of two types, called kappa (κ) and lambda (λ).

[0080] Full-length antibody, intact antibody, and whole antibody are interchangeable and generally include and / or refer to antibodies having a structure substantially similar to a native antibody structure or having a heavy chain containing an Fc region as defined herein.

[0081] A human consensus framework generally encompasses and / or refers to a framework that represents the most commonly occurring amino acid residues in a selection of human immunoglobulin VL or VH framework sequences. Generally, the selection of human immunoglobulin VL or VH sequences is derived from a subgroup of variable domain sequences. Generally, the subgroup of sequences is a subgroup in Kabat et al., Sequences of Proteins of Immunological Interest, 5th ed., NIH Publication, pp. 91-3242, Bethesda, MD (1991), vols. 1-3. In some embodiments, for VL, the subgroup is subgroup kappa I in Kabat et al., supra. In some embodiments, for VH, the subgroup is subgroup III in Kabat et al., supra. A humanized antibody encompasses and refers to a chimeric antibody comprising amino acid residues from a non-human HVR and amino acid residues from a human framework region (FR). In some embodiments, a humanized antibody comprises substantially all of at least one, and typically two, variable domains, in which all or substantially all of the HVRs (e.g., CDRs) correspond to those of a non-human antibody and all or substantially all of the FRs correspond to those of a human antibody. A humanized antibody optionally includes at least a portion of an antibody constant region derived from a human antibody. A "humanized form" of an antibody, e.g., a non-human antibody, refers to an antibody that has undergone humanization.

[0082] Complementarity determining region or CDR, which is synonymous with hypervariable region or HVR, generally comprises and / or refers to regions of an antibody that are hypervariable in sequence and / or form structurally defined loops (hypervariable loops) and / or contain antigen contact residues (antigen contacts). In some embodiments, complementarity determining region or CDR generally comprises and refers to non-contiguous sequences of amino acids within an antibody variable region that confer antigen specificity and / or binding affinity. Generally, there are three CDRs (CDR-H1, CDR-H2, CDR-H3) in each heavy chain variable region, and three CDRs (CDR-L1, CDR-L2, CDR-L3) in each light chain variable region.

[0083] Framework regions, or FRs, generally comprise and / or refer to the non-CDR portions of the heavy and light chain variable regions. Generally, there are four FRs (FR-H1, FR-H2, FR-H3, and FR-H4) in each full-length heavy chain variable region, and four FRs (FR-L1, FR-L2, FR-L3, and FR-L4) in each full-length light chain variable region. In some embodiments, framework regions are defined by the non-CDR sequences of the variable region sequences.The precise amino acid sequence boundaries of a given CDR or FR can be determined from Kabat et al. (1991) "Sequences of Proteins of Immunological Interest," 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD ("Kabat" numbering scheme); Al-Lazikani et al. (1997) JMB 273, 927-948 ("Chothia" numbering scheme); MacCallum et al. (1996) "Antibody-antigen interactions: Contact analysis and binding site topography," J. Mol. Biol. 262, 732-745 ("Contact" numbering scheme); Lefranc MP et al., "IMGT unique numbering for immunoglobulin and T cell receptor variable domains and Ig superfamily V-like domains," Dev Comp Immunol, 2003 Jan;27(1):55-77 (the "IMGT" numbering scheme), Honegger A and Pluckthun A, "Yet another numbering scheme for immunoglobulin variable domains: an automatic modeling and analysis tool", J Mol Biol, 2001 Jun 8;309(3):657-70 (the "Aho" numbering scheme), and Whitelegg NR and Rees AR, "WAM: an improved algorithm for modeling antibodies on the WEB", Protein Eng. 2000 Dec;13(12):819-24 (the "AbM" numbering scheme).In certain embodiments, the CDRs of the antibodies described herein can be defined by a method selected from Kabat, Chothia, IMGT, Aho, AbM, or a combination thereof. In some embodiments, the CDRs and FRs are defined by and / or according to the Kabat numbering scheme. In some embodiments, the CDRs and FRs are defined by and / or according to the Chothia numbering scheme. In some embodiments, the CDRs and FRs are defined by and / or according to the IMGT numbering scheme. In some embodiments, the CDRs and FRs are defined by and / or according to the EU numbering scheme.

[0084] The boundaries of a given CDR or FR may vary depending on the scheme used for identification in certain instances. For example, the Kabat scheme is based on structural alignment, while the Chothia scheme is based on structural information. The numbering in both the Kabat scheme and the Chothia scheme is based on the most common antibody region sequence length, with insertions represented by insertion letters, such as "30a," and deletions occurring in some antibodies. The two schemes place specific insertions and deletions ("indels") at different positions, resulting in differential numbering. The Contact scheme is based on the analysis of complex crystal structures and is similar in many respects to the Chothia numbering scheme.

[0085] The Fc region generally encompasses and / or refers to the C-terminal region of an immunoglobulin heavy chain containing at least a portion of the constant region. This term includes native sequence Fc regions and variant Fc regions. In some embodiments, a human IgG heavy chain Fc region extends from Cys226 or Pro230 to the carboxyl terminus of the heavy chain. However, the C-terminal lysine (Lys447) of the Fc region may or may not be present. Unless otherwise specified herein, the numbering of amino acid residues in the Fc region or constant region follows the EU numbering system, also known as the EU index, as described in Kabat et al., "Sequences of Proteins of Immunological Interest," 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD, 1991.

[0086] A human antibody generally includes and / or refers to an antibody having an amino acid sequence that corresponds to that of an antibody produced by a human or human cell, or derived from a non-human source that utilizes the human antibody repertoire or other human antibody-encoding sequences. This definition of a human antibody specifically excludes humanized antibodies that contain non-human antigen-binding residues.

[0087] An acceptor human framework region generally encompasses and / or refers to a framework that includes the amino acid sequence of a light chain variable domain (VL) framework or a heavy chain variable domain (VH) framework derived from a human immunoglobulin framework or a human consensus framework, as defined below. An acceptor human framework "derived from" a human immunoglobulin framework or a human consensus framework can include the same amino acid sequence thereof, or can include amino acid sequence changes. In some embodiments, the number of amino acid changes is 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less. In some embodiments, the VL acceptor human framework is identical in sequence to the VL human immunoglobulin framework sequence or the human consensus framework sequence.

[0088] The variable region or variable domain generally encompasses and / or refers to the domains of the heavy or light chain of an antibody that are involved in binding the antibody to an antigen. The variable domains of the heavy and light chains (V, V ... H and V L ) generally have similar structures, with each domain containing four conserved framework regions (FR) and three CDRs (see, for example, Kindt et al., Kuby Immunology, 6th ed., W.H. Freeman and Co., p. 91 (2007)). H or V L The V domain may be sufficient to confer antigen-binding specificity. Furthermore, an antibody that binds to a particular antigen may have a V domain derived from the antibody that binds to the antigen. H or V L The V domains were isolated and each was complementary to L or V H Libraries of domains can be screened (see, eg, Portolano et al., J. Immunol. 150:880-887 (1993); Clarkson et al., Nature 352:624-628 (1991)).

[0089] Affinity generally encompasses and / or refers to the strength of the total non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). Unless otherwise indicated, as used herein, binding affinity encompasses and refers to the intrinsic binding affinity, which generally reflects a 1:1 interaction between members of a binding pair (e.g., an antibody and an antigen). The affinity of a molecule X for its partner Y is generally determined by the dissociation constant (K D ) Affinity can be measured by common methods known in the art, including those described herein. Specific illustrative and exemplary embodiments for measuring binding affinity are described throughout.

[0090] Affinity matured antibodies generally encompass and / or refer to antibodies with one or more alterations in one or more hypervariable regions (HVRs) compared to an unchanged parent antibody, which alterations result in an improvement in the affinity of the antibody for antigen.

[0091] Binding and determination of binding (e.g., to an epitope comprising SEQ ID NO: 51) can be readily determined by methods known in the art (e.g., ELISA, surface plasmon resonance, biolayer interferometry, isothermal calorimetry, etc.). In some embodiments, binding is determined by ELISA. In some embodiments, binding is determined by a K of less than 10^-5 M (10 uM), e.g., as measured by surface plasmon resonance, biolayer interferometry, or isothermal calorimetry. D In some embodiments, binding can be measured by surface plasmon resonance, biolayer interferometry, or isothermal calorimetry, e.g., a K of less than 10^-6 M (1 uM). D In some embodiments, binding can be measured by surface plasmon resonance, biolayer interferometry, or isothermal calorimetry, e.g., a K of less than 10M (100nM). D Includes:

[0092] Chimeric antibodies generally encompass and / or refer to antibodies in which a portion of the heavy and / or light chain is derived from a particular source or species, while the remainder of the heavy and / or light chain is derived from a different source or species. The "class" of an antibody refers to the type of constant domain or constant region possessed by its heavy chain. There are five major classes of antibodies: IgA, IgD, IgE, IgG, and IgM, some of which can be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. The heavy chain constant domains corresponding to the different classes of immunoglobulins are called a, d, e, g, and m, respectively.

[0093] Monoclonal antibodies generally encompass and / or refer to antibodies obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical and / or bind to the same epitope, except for possible variant antibodies that contain, for example, naturally occurring mutations or arise during production of the monoclonal antibody preparation, and such variants are generally present in minor amounts within the composition. In contrast to polyclonal antibody preparations, which typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody of a monoclonal antibody preparation is directed against a single determinant on an antigen. In some embodiments, modifier monoclonal exhibits the properties of antibodies obtained from a substantially homogeneous antibody population, but should not be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies used in accordance with the invention within the composition disclosure can be made by a variety of techniques, including, but not limited to, hybridoma methods, recombinant DNA methods, phage display methods, and methods utilizing transgenic animals containing all or part of the human immunoglobulin loci; such methods, as well as other exemplary methods for making monoclonal antibodies, are described herein.

[0094] An isolated antibody generally encompasses and / or refers to an antibody that has been separated from a component of its natural environment. In some embodiments, the antibody is purified to greater than 95% or 99% purity, for example, as determined by electrophoresis (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatography (e.g., ion exchange or reverse-phase HPLC).

[0095] In certain embodiments, the antibody comprises one or more naturally occurring amino acids. In certain embodiments, the antibody consists of naturally occurring amino acids. As used herein, naturally occurring amino acids include and / or refer to amino acids that are commonly found in nature but have not been engineered by humans. In certain examples, naturally occurring includes and / or further refers to the 20 conventional amino acids: alanine (A or Ala), cysteine (C or Cys), aspartic acid (D or Asp), glutamic acid (E or Glu), phenylalanine (F or Phe), glycine (G or Gly), histidine (H or His), isoleucine (I or Ile), lysine (K or Lys), leucine (L or Leu), methionine (M or Met), asparagine (N or Asn), proline (P or Pro), glutamine (Q or Gln), arginine (R or Arg), serine (S or Ser), threonine (T or Thr), valine (V or VaI), tryptophan (W or Trp), and tyrosine (Y or Tyr).

[0096] In some embodiments, the antibody comprises a variant sequence of the antibody. In certain instances, amino acid substitutions can be made to the sequence of any of the antibodies described herein without necessarily reducing or eliminating its activity (e.g., as measured by a binding or functional assay described herein). Thus, in some embodiments, the variant sequence comprises one or more amino acid substitutions (e.g., within the variable region or one or more CDRs). In some embodiments, the variant sequence comprises one or more substitutions in one or more CDRs. In certain embodiments, the variant sequence comprises one amino acid substitution. In certain embodiments, the variant sequence comprises two amino acid substitutions. In certain embodiments, the variant sequence comprises three amino acid substitutions. In certain instances, the substitutions comprise conservative substitutions (e.g., substitutions with amino acids having equivalent chemical characteristics). In certain instances, a nonpolar amino acid can be substituted and exchanged with another nonpolar amino acid, where nonpolar amino acids include alanine, leucine, isoleucine, valine, glycine, proline, phenylalanine, tryptophan, and methionine. In certain examples, neutrally charged polar amino acids can be substituted and replaced with other neutrally charged polar amino acids, where neutrally charged polar amino acids include serine, threonine, cysteine, tyrosine, asparagine, and glutamine.In certain examples, positively charged amino acids can be substituted and replaced with other positively charged amino acids, where positively charged amino acids include arginine, lysine, and histidine.In certain examples, negatively charged amino acids can be substituted and replaced with other negatively charged amino acids, where negatively charged amino acids include aspartic acid and glutamic acid.Examples of amino acid substitution also include substituting L-amino acids with their corresponding D-amino acids, substituting cysteine with homocysteine or other unnatural amino acids.

[0097] In certain embodiments, the antibody comprises one or more unnatural amino acids. In certain embodiments, the antibody is composed of unnatural amino acids. As used herein, non-natural amino acids and / or unnatural amino acids include and / or refer to amino acid structures that cannot be biosynthetically produced in an organism using unmodified or modified genes from any organism. For example, these include, but are not limited to, modified amino acids and / or amino acid analogs that are not one of the 20 naturally occurring amino acids (e.g., unnatural side chain variant sequence amino acids), D-amino acids, homoamino acids, β-homoamino acids, N-methyl amino acids, and α-methyl amino acids. As further examples, unnatural amino acids also include 4-benzoylphenylalanine (Bpa), aminobenzoic acid (Abz), aminobutyric acid (Abu), aminohexanoic acid (Ahx), aminoisobutyric acid (Aib), citrulline (Cit), diaminobutyric acid (Dab), diaminopropanoic acid (Dap), diaminopropionic acid (Dap), gamma-carboxyglutamic acid (Gla), homoalanine (Hala), homoarginine (Harg), homoasparagine (Hasn), homoaspartic acid (Hasp), homocysteine (Hcys), homoglutamic acid (Hglu), homoglutamine (Hgln), homoisoleucine (Hile ... Also included are moroicine (Hleu), homomethionine (Hmet), homophenylalanine (Hphe), homoserine (Hser), homotyrosine (Htyr), homovaline (Hval), hydroxyproline (Hyp), isonipecotic acid (Inp), naphthylalanine (Nal), nipecotic acid (Nip), norleucine (Nle), norvaline (Nva), octahydroindole-2-carboxylic acid (Oic), penicillamine (Pen), phenylglycine (Phg), pyroglutamic acid (Pyr), sarcosine (Sar), t-butylglycine (Tle), and tetrahydro-isoquinoline-3-carboxylic acid (Tic).Such non-naturally occurring amino acid residues can be introduced by substitution of naturally occurring amino acids and / or by insertion of the non-naturally occurring amino acid into a naturally occurring antibody sequence. Non-naturally occurring amino acid residues can also be incorporated to confer a desired functionality to the apelin molecule, such as the ability to attach a functional moiety (e.g., PEG).

[0098] A stable formulation refers to and / or includes a formulation in which a protein (e.g., an antibody) therein essentially retains its physical and / or chemical stability and / or biological activity upon storage at the intended storage temperature, e.g., 2-8°C. In some embodiments, the formulation essentially retains its physical and chemical stability as well as its biological activity upon storage. The storage period can generally be selected based on the intended shelf life of the formulation. Furthermore, formulations are generally stable after freezing (e.g., to -20°C) and thawing the formulation, e.g., after one or more cycles of freezing and thawing. Various analytical techniques for measuring protein stability are available in the art and are reviewed, for example, in Peptide and Protein Drug Delivery, pp. 247-301, Vincent Lee (ed.), Marcel Dekker, Inc., New York, NY, Pubs. (1991), and Jones, A., Adv. Drug Delivery Rev. 10:29-90 (1993). Stability can be measured at a selected temperature over a selected period of time. Stability can be assessed qualitatively and / or quantitatively in a variety of different ways, including assessing aggregate formation (e.g., using size exclusion chromatography, by measuring turbidity, and / or by visual inspection), by assessing charge heterogeneity using cation exchange chromatography or capillary zone electrophoresis, by SDS-PAGE analysis for comparison with reduced, intact antibody, by assessing antibody biological activity or antigen-binding function, and by the methods described herein. Instability can include any one or more of aggregation, deamidation (e.g., Asn deamidation), oxidation (e.g., Met oxidation), isomerization (e.g., Asp isomerization), clipping / hydrolysis / fragmentation (e.g., hinge region fragmentation), succinimide formation, unpaired cysteines, etc.

[0099] A pharmaceutically acceptable carrier generally encompasses and / or refers to an ingredient in a pharmaceutical formulation other than the active ingredient that is non-toxic to a subject, including, but not limited to, a buffer, excipient, stabilizer, or preservative.

[0100] Polypeptide or protein are used interchangeably and generally encompass and / or refer to polymers of amino acid residues, without being limited to a minimum length. Polypeptides, including the provided antibodies, antibody chains, and other peptides, such as linkers and connecting peptides, can contain amino acid residues, including natural and / or unnatural amino acid residues. The term also includes post-expression modifications of the polypeptide, such as glycosylation, sialylation, acetylation, phosphorylation, and the like. In some embodiments, a polypeptide can contain modifications relative to its natural or native sequence, so long as the protein maintains a desired activity. These modifications can be deliberate, such as by site-directed mutagenesis, or can be accidental, such as by mutation of the host producing the protein or by errors during PCR amplification.

[0101] The percent sequence identity (%) to a reference polypeptide sequence is the percentage of amino acid residues in a candidate sequence that are identical to those in the reference polypeptide sequence, after aligning the sequences and introducing gaps as necessary to achieve the maximum percent sequence identity, but does not consider any conservative substitutions as part of the sequence identity. Alignment for the purpose of determining percent amino acid sequence identity can be achieved in a variety of known ways, for example, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. Appropriate parameters for aligning sequences can be determined, including the algorithm required to achieve maximum alignment across the entire length of the sequences being compared. However, for the purposes of this specification, percent amino acid sequence identity values are generated using the sequence comparison computer program ALIGN-2. The ALIGN-2 sequence comparison computer program is from Genentech, Inc., and its source code has been filed with the U.S. Copyright Office, Washington, DC 20559, along with user documentation, and is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available from Genentech, Inc., South San Francisco, Calif., or may be compiled from the source code. The ALIGN-2 program must be compiled for use on UNIX operating systems, including Digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary.

[0102] As used herein, the terms individual, patient, or subject generally include and / or refer to an individual who has been diagnosed with, is suspected of suffering from, or is at risk of developing at least one disease, disorder, or condition that the described compositions and methods are useful for treating. In certain embodiments, the individual is a mammal. In certain embodiments, the mammal is a mouse, rat, rabbit, dog, cat, horse, cow, sheep, pig, goat, llama, alpaca, or yak. In certain embodiments, the individual is a human.

[0103] The antibodies described herein can be encoded by nucleic acids. Nucleic acids are a type of polynucleotide containing two or more nucleotide bases. In certain embodiments, nucleic acids are components of vectors that can be used to introduce a polypeptide encoded by a polynucleotide into a cell. As used herein, the term "vector" refers to a nucleic acid molecule capable of transporting another nucleic acid to which it is linked. One type of vector is a genomic integration vector or "integration vector," which can be integrated into the chromosomal DNA of a host cell. Another type of vector is an "episomal" vector, e.g., a nucleic acid capable of extrachromosomal replication. Vectors capable of inducing the expression of an operably linked gene are referred to herein as "expression vectors." Suitable vectors include plasmids, bacterial artificial chromosomes, yeast artificial chromosomes, viral vectors, and the like. In expression vectors, regulatory elements such as promoters, enhancers, and polyadenylation signals used to control transcription can be derived from mammalian, microbial, viral, or insect genes. The ability to replicate in a host, usually conferred by an origin of replication, and a selection gene for easy recognition of transformants may also be incorporated. Vectors derived from viruses such as lentivirus, retrovirus, adenovirus, and adeno-associated virus may also be used. Plasmid vectors can be linearized for integration into genomic regions. In certain embodiments, the expression vector is a plasmid. In certain embodiments, the expression vector is a lentivirus, adenovirus, or adeno-associated virus. In certain embodiments, the expression vector is an adenovirus. In certain embodiments, the expression vector is an adeno-associated virus. In certain embodiments, the expression vector is a lentivirus.

[0104] As used herein, the terms "homologous," "homology," or "percent homology," when used herein to describe an amino acid sequence or a nucleic acid sequence relative to a reference sequence, can be determined using the formula described by Karlin and Altschul (Proc. Natl. Acad. Sci. USA 87:2264-2268, 1990, rev. Proc. Natl. Acad. Sci. USA 90:5873-5877, 1993). Such formula is incorporated into the basic local alignment search tool (BLAST) program of Altschul et al. (J. Mol. Biol. 215:403-410, 1990). Percent sequence homology can be determined using the most recent version of BLAST available as of the filing date of this application.

[0105] Nucleic acids encoding the antibodies described herein can be used to infect, transfect, transform, or otherwise render suitable cells transgenic for the nucleic acid, thereby enabling the production of the antibody for commercial or therapeutic use. Standard cell lines and methods for large-scale cell culture antibody production are known in the art. See, for example, Li et al., "Cell culture processes for monoclonal antibody production." Mabs. 2010 Sep-Oct;2(5):466-477. In certain embodiments, the cell is a eukaryotic cell. In certain embodiments, the eukaryotic cell is a mammalian cell. In certain embodiments, the mammalian cell is a cell line useful for antibody production, such as a Chinese hamster ovary (CHO) cell, an NS0 mouse myeloma cell, or a PER.C6® cell. In certain embodiments, the antibody-encoding nucleic acid is integrated into a genetic locus of a cell useful for antibody production. In certain embodiments, described herein are methods of making an antibody, comprising culturing cells containing an antibody-encoding nucleic acid under in vitro conditions sufficient to allow the production and secretion of the antibody.

[0106] In certain embodiments, described herein is a master cell bank comprising (a) a mammalian cell line comprising a nucleic acid encoding an antibody described herein integrated at a genomic location, and (b) a cryoprotectant. In certain embodiments, the cryoprotectant comprises glycerol or DMSO. In certain embodiments, the master cell bank comprises (a) a CHO cell line comprising a nucleic acid encoding an antibody of the disclosure, and (b) a cryoprotectant. In certain embodiments, the cryoprotectant comprises glycerol or DMSO. In certain embodiments, the master cell bank is contained in a suitable vial or container that can withstand freezing with liquid nitrogen.

[0107] Also described herein are methods for producing the antibodies described herein. Such methods include incubating cells or cell lines containing nucleic acids encoding the antibodies in cell culture medium under conditions sufficient to allow expression and secretion of the antibodies, and further harvesting the antibodies from the cell culture medium. Harvesting can further include one or more purification steps to remove viable cells, cell debris, non-antibody proteins or polypeptides, undesired salts, buffers, and medium components. In certain embodiments, additional purification steps include centrifugation, ultracentrifugation, Protein A, Protein G, Protein A / G, or Protein L purification, and / or ion exchange chromatography.

[0108] As used herein, "Treat," "treatment," or "treating" refers to the deliberate intervention in a physiological disease state that results in, for example, a reduction in the severity of a disease or condition, a shortening of the duration of the disease course, an alleviation or elimination of one or more symptoms associated with a disease or condition, or the provision of a beneficial effect to a subject with a disease or condition. Treatment does not require a cure of the underlying disease or condition.

[0109] A "therapeutically effective amount," "effective dose," "effective amount," or "therapeutically effective dose" of a drug or therapeutic agent is that amount of drug, when used alone or in combination with another therapeutic agent, that protects a subject from developing disease or promotes disease regression as evidenced by a decrease in the severity of disease symptoms, an increase in the frequency and duration of disease-free periods, or prevention of functional impairment or disability due to disease affliction. The ability of a therapeutic agent to promote disease regression can be assessed using a variety of methods known to those skilled in the art, such as by assaying the activity of the agent in human subjects during clinical trials, in animal model systems predictive of efficacy in humans, or in in vitro assays.

[0110] As used herein, "pharmaceutically acceptable" with respect to "carriers," "excipients," or "diluents" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like that are physiologically compatible. In some embodiments, the carrier is suitable for intravenous, intramuscular, subcutaneous, parenteral, spinal, or epidermal administration (e.g., by injection or infusion). Depending on the route of administration, the active compound, i.e., antibody, may be coated with a material to protect the compound from the action of acids and other natural conditions that may inactivate the compound.

[0111] The pharmaceutical compounds described herein may contain one or more pharmaceutically acceptable salts. A "pharmaceutically acceptable salt" refers to a salt that retains the desired biological activity of the parent compound but does not impart any undesired toxicological effects (see, e.g., Berge, SM et al. (1977) J. Pharm. Sci. 66:1-19). Examples of such salts include acid addition salts and base addition salts. Acid addition salts include those derived from non-toxic inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, and phosphorous acid, as well as non-toxic organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxyalkanoic acids, aromatic acids, and aliphatic and aromatic sulfonic acids. Base addition salts include those derived from alkaline earth metals such as sodium, potassium, magnesium, and calcium, as well as non-toxic organic amines such as N,N'-dibenzylethylenediamine, N-methylglucamine, chloroprocaine, choline, diethanolamine, ethylenediamine, and procaine.

[0112] As used herein, treatment or treating generally includes and / or refers to a pharmaceutical or other intervention regimen used to obtain a beneficial or desired result in the recipient. Beneficial or desired results include, but are not limited to, therapeutic benefit and / or prophylactic benefit. Therapeutic benefit can refer to the eradication or amelioration of the symptom or underlying disease being treated. Therapeutic benefit can also be achieved by the eradication or amelioration of one or more physiological symptoms associated with the underlying disorder, such that the subject observes improvement, even though the subject may still be afflicted with the underlying disorder. Prophylactic benefit includes delaying, preventing, or eliminating the appearance of the disease or condition, delaying or eliminating the onset of symptoms of the disease or condition, slowing, halting, or reversing the progression of the disease or condition, or any combination thereof. In the case of prophylactic benefit, a subject at risk of developing a particular disease or reporting one or more physiological symptoms of the disease may receive treatment even if the disease has not been diagnosed. One skilled in the art will recognize that, considering a population of individuals who are candidates for treatment, not all will respond or respond equally to the treatment; such individuals will be considered treated.

[0113] In some embodiments, treating misfolded λ light chains and / or treating λ light chain amyloid deposits or treating λ light chain aggregates may be used interchangeably herein. In some embodiments, treating misfolded λ light chains includes treating a disorder characterized by misfolded λ light chains. In some embodiments, treating misfolded λ light chains includes reducing and / or reducing and / or inhibiting λ light chain aggregates or symptoms thereof (e.g., by measuring freely circulating light chains). In some embodiments, treating misfolded λ light chains includes promoting clearance of misfolded λ light chains by monocytic cells and / or phagocytes (e.g., by measuring freely circulating light chains).

[0114] As used herein, monocytes or monocytic cells refer to and / or include a type of white blood cell or white blood cell. Monocytes are the largest class of white blood cells and can differentiate into, for example, macrophages. As part of the innate immune system of vertebrates, monocytes also influence the process of adaptive immunity. Monocytes can generally be classified into three types of monocytes in human blood: 1) classical monocytes can be characterized by high-level expression of the CD14 cell surface receptor (CD14 ++ CD16 - monocytes), and 2) non-classical monocytes, which show low levels of CD14 expression and additional co-expression of the CD16 receptor (CD14 + CD16 ++ monocytes), 3) intermediate monocytes have high levels of CD14 and low levels of CD16 (CD14 ++ CD16 + monocytes).

[0115] As used herein, macrophage generally refers to and / or includes a type of white blood cell of the immune system that engulfs and digests cellular debris, foreign bodies, microorganisms, cancer cells, and other objects that do not have the types of proteins specific to healthy body cells on their surface in a process called phagocytosis. In addition to increasing inflammation and stimulating the immune system, macrophages can play an important anti-inflammatory role and can reduce immune responses through the release of cytokines.

[0116] As used herein, phagocytes generally refer to and / or include cells capable of phagocytosis, including both professional and non-professional phagocytes.

[0117] As used herein, amyloidosis generally refers to and / or encompasses diseases or conditions characterized by misfolding of free immunoglobulin light chains (LC) (e.g., λLC), which can be deposited as light chain amyloid (AL) in the heart, kidney, or liver. This disease is typically caused by an underlying plasma cell dysplasia that results in plasma cells secreting a large excess of free immunoglobulin kappa (κ) and / or lambda (λ) light chains into the circulation. In certain instances, circulating immunoglobulin kappa (κ) and / or lambda (λ) light chains tend to misfold, aggregate, and / or form amyloid deposits; i.e., aggregated primary amyloidosis or AL amyloidosis generally refers to and / or encompasses the most common type of systemic amyloidosis, occurring in 9 to 14 people per year in Western countries.

[0118] As used herein, plasma cell dysplasia generally refers to and / or encompasses proliferative plasma cell disorders in which a single abnormal plasma cell clone (terminally differentiated B cell) undergoes unregulated proliferation and produces greater than normal amounts of light chain proteins (e.g., misfolded LC proteins). Plasma cell dysplasias can be classified as either benign, as seen in monoclonal gammopathy of undetermined significance (MGUS), or malignant, as seen in multiple myeloma (MM) and plasma cell leukemia (PCL). Regardless of the type of dysplasia involved, these secreted light chains may undergo misfolding events that tend to aggregate and accumulate as amyloid in vital organs, including the heart, kidneys, and nervous system. Such infiltration can lead to nephrotic syndrome, hepatomegaly, peripheral neuropathy, restrictive cardiomyopathy, and ultimately death.

[0119] As used herein, the words comprising (and all forms of comprising, such as comprise and comprise'), having (and all forms of having, such as have and has'), including (and all forms of including, such as include and includes'), or containing (and all forms of containing, such as contain and contains') are inclusive or open-ended and do not exclude additional, unlisted elements or process steps. Also, as used herein, in any example or embodiment described herein, comprising may be replaced with consisting essentially of and / or consisting of, and in any example or embodiment described herein, comprises may be replaced with consists essentially of and / or consists of.

[0120] As used herein, the term about in the context of a given value or range includes and / or refers to values or ranges that are within 20%, within 10%, and / or within 5% of the given value or range.

[0121] As used herein, the term and / or should be construed as a specific disclosure of each of the two specified features or components, regardless of the presence or absence of the other. For example, A and / or B should be construed as a specific disclosure of each of (i) A, (ii) B, and (iii) A and B, as if each were individually set forth herein. [Example]

[0122] The following illustrative examples represent embodiments of the compositions and methods described herein and are not meant to be limiting in any way.

[0123] Example 1 - Anti-human gamma light chain antibody A problem that has been at least partially solved is the creation of conformation-specific antibodies that bind to organ-deposited toxic light chains or their misfolded precursors in the circulation, while leaving fully folded circulating light chains untouched. Solving this problem provides a solution for directly addressing pathogenic species with high efficacy while avoiding interactions with the often abundant, non-pathologically folded free light chains that can act as a biological sink or result in undesirable immune side effects during treatment. Without being bound by theory, antibody binding to misfolded species targets them for elimination via the antibody-dependent cellular phagocytosis (ADCP) mechanism.

[0124] The light chain contains a variable domain (V L , AA1-108) and a constant domain (C L The variable domain contains a hypervariable region with a different amino acid sequence in every patient, whereas the constant domain shares sequence identity in all patients with the same isotype (κ or λ). The unique light chain variable domain sequence in each patient is thought to confer unique properties of the protein, such as amyloidogenic tendency or amyloid structure, and much of the research effort has been focused on targeting this domain.

[0125] Currently, there are two competing products aimed at using antibody-based amyloid-reducing mechanisms to treat AL amyloidosis: Caelum CAEL-101 (Phase III in progress) and NEOD001 (Phase III, failed). Both companies are using a strategy of creating a single antibody against the variable domain to treat both kappa and lambda AL amyloidosis patient populations. While these antibodies have been reported to be effective in all patients (kappa and lambda), discordance in target engagement between these antibodies, as demonstrated by immunohistochemistry and clinical response measurements, has emerged in both preclinical and clinical trials. This discordance may be due to the epitopes CAEL-101 and NEOD001. NEOD001 was originally designed to target serum amyloid A, but was found to have cross-reactivity to the light chain through interaction with a two-amino acid epitope on the variable domain of the light chain protein. CAEL-101 was generated against an epitope in kappa AL patients. Recent cryo-EM structures of lambda light chain amyloid extracted from patients have shown that the epitopes targeted by CAEL-101 and NEOD001 may be buried in the core of the amyloid fibrils (e.g., inaccessible to antibodies) in one patient's light chain but accessible in another, potentially resulting in significant differences in binding affinity and clinical efficacy between individuals.

[0126] The antibody design approach to generating anti-human light chain antibodies is to identify misfolding-specific epitopes on the invariant constant domain, resulting in antibodies that bind to all variants of the same isotype with similar affinity. Laser capture microdissection mass spectrometry (LC-MS) studies have shown that the constant domain of the light chain (not just the variable domain) is co-deposited in diseased tissues as full-length light chains or constant domain fragments, making them candidate targets for antibody therapy that exploits amyloid-reducing mechanisms. Therefore, the K chain and light chain can also be considered two separate targets.

[0127] The anti-human light chain antibodies described herein were generated to bind to the misfolding-specific epitope NKYAASSYLSL (SEQ ID NO: 51) on the λ light chain protein. To generate misfolding-specific antibodies, mice were immunized with an immunogen representing the misfolding-specific epitope, and splenocytes were subsequently harvested and used to generate mouse hybridoma cells using established methods. Thirteen clones were identified and purified from mouse ascites fluid, and then screened for the desired misfolding-specific properties.

[0128] Antibodies that bind to denatured light chains First, we tested the binding ability of each of the 13 clones to unfolded λ light chains using Western blotting to determine whether the antibodies could recognize our target epitope in the context of full-length, unfolded λ light chains. Pooled λ light chains from the sera of multiple myeloma patients were used in the binding assay. For comparison, pooled unfolded κ immunoglobulin light chains were used, as well as whole serum from patients with a confirmed diagnosis of λ light chain (AL) amyloidosis. Figure 1 shows data demonstrating that five of the candidate antibodies successfully detected one or more bands in patient serum samples, as well as denatured (SDS-unfolded) λ light chain protein. All clones (clones 1–5) showed strong binding to denatured light chains. Clones 4–5 also clearly cross-reacted with denatured κ light chains. Not all of the 13 clones showed binding to unfolded λ light chains. The identified clones are as follows:

[0129] Clone 1 contains CDRs identified / derived from a heavy chain variable domain comprising SEQ ID NO:1 and a light chain variable domain comprising SEQ ID NO:2.

[0130] Clone 2 contains CDRs identified / derived from a heavy chain variable domain comprising SEQ ID NO:11 and a light chain variable domain comprising SEQ ID NO:12.

[0131] Clone 3 contains CDRs identified / derived from a heavy chain variable domain comprising SEQ ID NO:21 and a light chain variable domain comprising SEQ ID NO:22.

[0132] Clone 4 contains CDRs identified / derived from a heavy chain variable domain comprising SEQ ID NO:31 and a light chain variable domain comprising SEQ ID NO:32.

[0133] Clone 5 contains CDRs identified / derived from a heavy chain variable domain comprising SEQ ID NO:41 and a light chain variable domain comprising SEQ ID NO:42.

[0134] Preferential binding to misfolded over native conformations Among the five modified light chain binders, we addressed whether these candidate monoclonal antibodies could distinguish and specifically bind non-native λ light chain proteins, rather than native (fully folded) forms. As a representative λ light chain clone, we selected Wil, a long-tested λ light chain variant first identified and sequenced in an individual with light chain amyloidosis (Pokkuluri et al., 1999). Full-length native Wil was produced by recombinant expression in vitro using established methods. Wil, when expressed and purified under these conditions, forms stable, native-like light chain dimers. Stable misfolded / unfolded Wil was then generated by treatment of the native protein with urea and a reducing agent, followed by alkylation, which permanently disrupts disulfide bond formation.

[0135] An indirect ELISA assay was performed to compare the binding of each antibody clone to native and misfolded / unfolded wild-type wild-type wild-type. A 96-well immunoassay plate was coated with a range of amounts of native or misfolded / unfolded wild-type wild-type wild-type wild-type (0–800 ng protein per well), and each well was probed with our candidate antibody or a commercial control. As illustrated in Figures 2A–2F, bound antibody was detected using an HRP-conjugated secondary antibody and standard TMB chemistry. As demonstrated in Figures 2A–2B, clones 1 and 2 each showed high overall signals but also substantial binding to native wild-type wild-type wild-type wild-type wild-type (although less than misfolded / unfolded wild-type wild-type wild-type). As demonstrated in Figure 2C, clone 3 showed a slightly weaker signal but slightly better discrimination between native wild-type ... As demonstrated in Figures 2D-E, clones 4 (Figure 2D) and 5 (Figure 2E) exhibited the weakest overall signal but were highly specific for misfolded Wil in this assay format. In contrast to the pan-specific commercial antibody shown in Figure 2F, all five clones demonstrated some ability to discriminate between misfolded / unfolded and native λ light chains.

[0136] Preferential binding to aggregated / amyloid light chains over native conformations As illustrated in Figure 3, five clones were tested for their ability to bind to aggregated forms of λ light chain (amyloid, the cause of disease) using native Western blots. Using previously established methods, we induced the formation of Wil aggregates and amyloid by prolonged shaking at high temperature, and verified amyloid formation using the amyloid-sensitive dye, thioflavin T. Native Western blots were performed under "mild," low-detergent conditions designed to preserve the folding of protein samples, and we compared the binding of our mAbs to native dimeric Wil, misfolded / unfolded Wil, and aggregated / amyloid Wil.

[0137] All candidate mAbs detected both misfolded / unfolded Wil and amyloid / aggregated Wil. However, clones 1 and 2 showed the highest signal for the misfolded form of Wil. Although staining for the native band was present, the signal was significantly reduced. We suspected that Western blotting and indirect ELISA, which immobilize "native" Wil protein on a surface, may result in false-positive binding to the native protein by inducing some degree of misfolding that is not detected by the weakly binding clones (clones 3–5). Therefore, we used a capture-format ELISA to examine the binding behavior of clones 1 and 2. In this format, a goat anti-mouse Fc capture antibody was coated onto ELISA wells, and clones 1 and 2 were captured with an antibody whose Fab was aligned appropriately. Biotinylated Wil in its native or misfolded form was then added to these wells, and binding was measured using streptavidin. As shown in Figures 4A and 4B, under these native conditions where Wil is in the solution phase, we observed minimal binding to native Wil and preferential binding to the misfolded form in both clones 1 and 2, suggesting conformational specificity. Both clone 1 (Figure 5A) and clone 2 (Figure 5B) had affinities measured by biolayer interferometry (BLI) with K , respectively.D were 59 nM and 256 nM. Based on the above data, clone 1 was selected as the lead candidate for further characterization (hereafter referred to as muLX-97).

[0138] In vitro characterization of muLX-97 We then measured the binding affinity of muLX-97 for multiple lambda light chain variants in their misfolded and native conformations. In addition to Wil, we selected two light chain variants sequenced from cardiac amyloid deposits in patients with light chain amyloidosis. See Oberti L et al., "Concurrent structural and biophysical traits link with immunoglobulin light chains amyloid propensity." Sci Rep. 2017 Dec 1;7(1):16809, and Baur J et al., "Identification of AL proteins from 10 lambda-AL amyloidosis patients by mass spectrometry extracted from abdominal fat and heart tissue." Amyloid. 2023 Mar;30(1) pp.27-37. Again, we used BLI to monitor the association and dissociation of misfolded and native forms of Wil (Figures 6A and 6D), H3 (Figures 6B and 6E), and FOR102 (Figures 6C and 6F) when bound to muLX-97. The binding affinities of muLX-97 for misfolded Wil, H3, and FOR102 were 59, 317, and 65 nM, respectively. Only weak binding (limited BLI signal, even at very high concentrations of 1000 nM) was observed for the native conformations of all variants. This limited association may be due to the presence of small amounts of misfolded Wil contaminating the "native" samples. Together, this demonstrates that the conformational specificity of muLX-97 can be generalized to all lambda light chain variants.

[0139] Next, we determined the binding affinity of muLX-97 to the amyloid form of the λ light chain. Because the true affinity for aggregates could not be measured using previously described methods in which either the antibody or the target was immobilized, we used microscale thermophoresis (MST). In this method, an infrared laser is irradiated onto a small spot in a capillary containing a fluorescently labeled antibody in the presence or absence of the target. Localized heating causes migration of the protein from the heated spot, and the rate of change in migration (due to antibody binding to the ligand) can be used to measure affinity. Using a NanoTemper Monolith, we quantified the binding of muLX-97 to the misfolded and amyloid forms of Wil, and the results are shown in Figure 7. As shown in Figure 7A, the K for misfolded Wil was significantly higher than that for the non-misfolded form. D The binding affinity of muLX-97 to amyloid Wil was 61 nM, consistent with the results of ELISA (Figure 4A) and BLI (Figure 6A), whereas Figure 7B shows that the affinity for amyloid Wil was 87 nM. These results support the idea that muLX-97 binds with high specificity to both the misfolded and amyloid forms of λ light chains. The binding affinities of λAL variants determined using various methods are summarized in Table 1.

[0140] [Table 1]

[0141] Example 2 - Anti-human λ light chain antibodies that bind to human tissue amyloid Ex vivo validation of muLX-97 target engagement Next, we evaluated whether muLX-97 could engage disease-relevant targets in biopsy-confirmed λ patient tissues. We performed IHC and Congo Red co-staining on several cases of patients with λ light chain amyloidosis. Congo Red is an amyloid-specific dye that can be visualized by fluorescence microscopy. Two representative cases are shown as examples. In gastrointestinal cases, the IHC staining pattern (Figure 8A, dark staining) and the Congo Red fluorescence pattern (Figure 8C, white on a dark background) closely matched in distribution and morphology. Similarly, this same co-staining was demonstrated in soft tissues (Figures 8B and 8D). The co-staining results confirm that muLX-97 is amyloid-specific in biopsy-confirmed cases of λAL amyloidosis, as it stains morphologies consistent with amyloid.

[0142] Positive staining for the five biopsy-confirmed cases of λAL was also demonstrated in the gastrointestinal (Figures 9A and 9B), renal (Figure 9C), and soft tissues (Figures 9D and 9E), whereas no staining was observed in pancreatic (Figure 9F) or cardiac (Figure 9G) tissue from patients with islet amyloid polypeptide amyloidosis or transthyretin amyloidosis, respectively. These results demonstrate that the disease-specific epitopes described herein are likely universal targets present in all cases of λAL amyloidosis, and that antibodies raised against these epitopes, such as muLX-97, are specific, targeted, and have very low risk of cross-reactivity to other tissues.

[0143] Example 3 - Anti-human λ light chain antibodies induce ADCP Antibody-dependent phagocytosis of λAL amyloid After confirming the binding affinity and target engagement of muLX-97, the ability of muLX-97 to induce an immune response and lead to immune-mediated clearance of amyloid through antibody-mediated cellular phagocytosis (ADCP) was tested in a cellular model. In this model, amyloid Wil was conjugated to a pH-sensitive dye, pH-sensitive rhodamine (pHrodo), and incubated with cultured macrophage cells and various concentrations of muLX-97 or an isotype control antibody. When phagocytic uptake occurs, amyloid is transported to lysosomes, where a decrease in pH causes fluorescence in phagocytic cells.

[0144] We evaluated the ability of muLX-97 to induce ADCP in murine macrophages using an ADCP model system (RAW264.7 and J774.1 cell lines). 40,000 cells were incubated with 2 μM pHrodo-labeled Wil amyloid and 0.1–200 nM muLX-97 or isotype control antibody. In RAW264.7 murine macrophages, we observed a significant increase in the percentage of pHrodo-positive cells incubated with muLX-97 (Figure 10B) compared with isotype antibody at antibody concentrations as low as 7.4 nM (Figure 10A). In J744.1 cells, the phagocytic effect was much more pronounced (up to 80% of cells were pHrodo-positive), and enhanced phagocytosis in muLX-97-treated cells (Figure 11B) was observed at an antibody concentration of 7.4 nM compared with cells treated with the isotype control (Figure 11A).

[0145] Quantifying the percentage of pHrodo-positive cells as a function of antibody concentration in these two model systems, muLX-97 exhibited an EC of approximately 20 nM in RAW264.7 cells. 50 and 50% of the maximum signal (Figure 12A), and an EC of approximately 7 nM in J774.1 cells. 50and 80% of the maximum signal (Figure 12B). In summary, this cell model demonstrates that muLX-97 significantly enhances macrophage-mediated clearance of λAL amyloid upon binding in a concentration-dependent manner, and the potency of this effect occurs at substoichiometric concentrations of antibody.

[0146] While preferred embodiments of the present invention within the disclosure of compositions have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the present disclosure. It is understood that various alternatives to the embodiments described herein may be utilized in practicing the present invention. The following claims define the scope of the embodiments disclosed herein, and it is intended that methods and structures within the scope of these claims and their equivalents be covered thereby.

[0147] All publications, patent applications, published patents, and other documents mentioned herein are incorporated by reference herein as if each individual publication, patent application, published patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions contained in texts incorporated by reference are excluded to the extent they conflict with definitions in the present disclosure.

[0148] [Table 2-1]

[0149] [Table 2-2]

[0150] [Table 2-3]

[0151]

Table 2-4

[0152]

Table 2-5

[0153]

Table 2-6

[0154]

Table 2-7

Claims

1. (I) (a) Heavy chain complementarity determination region 1 (H-CDR1) containing the amino acid sequence described in SEQ ID NO: 3, (b) Heavy chain complementarity determination region 2 (H-CDR2) containing the amino acid sequence described in SEQ ID NO: 4, (c) Heavy chain complementarity determination region 3 (H-CDR3) containing the amino acid sequence described in Sequence ID No. 5, (d) Light chain complementarity determination region 1 (L-CDR1) containing the amino acid sequence described in SEQ ID NO: 6, (e) Light chain complementarity determination region 2 (L-CDR2) containing the amino acid sequence described in SEQ ID NO: 7, and (f) Light chain complementarity determination region 3 (L-CDR3) containing the amino acid sequence described in Sequence ID No. 8 Includes, or (II) (a) Heavy chain complementarity determination region 1 (H-CDR1) containing the amino acid sequence described in SEQ ID NO: 13, (b) Heavy chain complementarity determination region 2 (H-CDR2) containing the amino acid sequence described in SEQ ID NO: 14, (c) Heavy chain complementarity determination region 3 (H-CDR3) containing the amino acid sequence described in SEQ ID NO: 15, (d) Light chain complementarity determination region 1 (L-CDR1) containing the amino acid sequence described in SEQ ID NO: 16, (e) Light chain complementarity determination region 2 (L-CDR2) containing the amino acid sequence described in SEQ ID NO: 17, and (f) Light chain complementarity determination region 3 (L-CDR3) containing the amino acid sequence described in SEQ ID NO: 18 Includes, or (III) (a) Heavy chain complementarity determination region 1 (H-CDR1) containing the amino acid sequence described in SEQ ID NO: 23, (b) Heavy chain complementarity determination region 2 (H-CDR2) containing the amino acid sequence described in SEQ ID NO: 24, (c) Heavy chain complementarity determination region 3 (H-CDR3) containing the amino acid sequence described in Sequence ID No. 25, (d) Light chain complementarity determination region 1 (L-CDR1) containing the amino acid sequence described in SEQ ID NO: 26, (e) Light chain complementarity determination region 2 (L-CDR2) containing the amino acid sequence described in SEQ ID NO: 27, and (f) Light chain complementarity determination region 3 (L-CDR3) containing the amino acid sequence described in Sequence ID No. 28 Includes, or (IV) (a) Heavy chain complementarity determination region 1 (H-CDR1) containing the amino acid sequence described in SEQ ID NO: 33, (b) Heavy chain complementarity determination region 2 (H-CDR2) containing the amino acid sequence described in SEQ ID NO: 34, (c) Heavy chain complementarity determination region 3 (H-CDR3) containing the amino acid sequence described in Sequence ID No. 35, (d) Light chain complementarity determination region 1 (L-CDR1) containing the amino acid sequence described in SEQ ID NO: 36, (e) Light chain complementarity determination region 2 (L-CDR2) containing the amino acid sequence described in SEQ ID NO: 37, and (f) Light chain complementarity determination region 3 (L-CDR3) containing the amino acid sequence described in SEQ ID NO: 38 Includes, or (V) (a) Heavy chain complementarity determination region 1 (H-CDR1) containing the amino acid sequence described in SEQ ID NO: 43, (b) Heavy chain complementarity determination region 2 (H-CDR2) containing the amino acid sequence described in SEQ ID NO: 44, (c) Heavy chain complementarity determination region 3 (H-CDR3) containing the amino acid sequence described in Sequence ID No. 45, (d) Light chain complementarity determination region 1 (L-CDR1) containing the amino acid sequence described in SEQ ID NO: 46, (e) Light chain complementarity determination region 2 (L-CDR2) containing the amino acid sequence described in SEQ ID NO: 47, and (f) Light chain complementarity determination region 3 (L-CDR3) containing the amino acid sequence described in Sequence ID No. 48 An anti-human λ light chain antibody or a human λ light chain binding fragment thereof, comprising an anti-human λ light chain antibody or a human λ light chain binding fragment thereof that binds to a misfolded λ light chain.

2. (I) (a) A heavy chain variable region comprising an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 1, and (b) further comprising a light chain variable region having at least about 80% sequence identity with respect to SEQ ID NO: 2, or (II) (a) A heavy chain variable region comprising an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 11, and (b) further comprising a light chain variable region having at least about 80% sequence identity with SEQ ID NO: 12, or (III) (a) A heavy chain variable region comprising an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 21, and (b) further comprising a light chain variable region having an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 22, or (IV) (a) A heavy chain variable region comprising an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 31, and (b) further comprising a light chain variable region having an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 32, or (V) (a) A heavy chain variable region comprising an amino acid sequence having at least about 80% sequence identity with SEQ ID NO: 41, and (b) The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, further comprising a light chain variable region having an amino acid sequence having at least about 80% sequence identity with SEQ ID NO:

42.

3. (I) (a) A heavy chain variable region comprising an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 1, and (b) further comprising a light chain variable region having at least about 90% sequence identity with SEQ ID NO: 2, or (II) (a) A heavy chain variable region comprising an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 11, and (b) further comprising a light chain variable region having an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 12, or (III) (a) A heavy chain variable region comprising an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 21, and (b) further comprising a light chain variable region having an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 22, or (IV) (a) A heavy chain variable region comprising an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 31, and (b) further comprising a light chain variable region having an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 32, or (V) (a) A heavy chain variable region comprising an amino acid sequence having at least about 90% sequence identity with SEQ ID NO: 41, and (b) The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, further comprising a light chain variable region having an amino acid sequence having at least about 90% sequence identity with SEQ ID NO:

42.

4. (I) (a) A heavy chain variable region containing the amino acid sequence described in Sequence ID No. 1, and (b) further comprising a light chain variable region containing the amino acid sequence described in Sequence ID No. 2, or (II) (a) A heavy chain variable region containing the amino acid sequence described in SEQ ID NO: 11, and (b) further comprising a light chain variable region containing the amino acid sequence described in SEQ ID NO: 12, or (III) (a) A heavy chain variable region containing the amino acid sequence described in SEQ ID NO: 21, and (b) further comprising a light chain variable region containing the amino acid sequence described in SEQ ID NO: 22, or (IV) (a) A heavy chain variable region containing the amino acid sequence described in SEQ ID NO: 31, and (b) further comprising a light chain variable region containing the amino acid sequence described in SEQ ID NO: 32, or (V) (a) A heavy chain variable region containing the amino acid sequence described in SEQ ID NO: 41, and (b) The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, further comprising a light chain variable region containing the amino acid sequence described in SEQ ID NO:

42.

5. The anti-human λ light chain antibody or its human λ light chain conjugate fragment according to claim 1, wherein the anti-human λ light chain antibody is a monoclonal antibody.

6. The anti-human λ light chain antibody or its human λ light chain conjugate fragment according to claim 1, wherein the anti-human λ light chain antibody is a chimeric antibody, a humanized antibody, or a human antibody.

7. The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, wherein the human λ light chain conjugate antibody fragment comprises Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, a dimer, or a minibody.

8. The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, wherein the IgG antibody is an IgG antibody.

9. The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 8, wherein the IgG antibody is of the IgG1 isotype.

10. The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 8, wherein the IgG antibody is of the IgG4 isotype.

11. The anti-human λ light chain antibody or human λ light chain conjugate fragment according to claim 1, wherein the anti-human λ light chain antibody or human λ light chain conjugate fragment is bound to an epitope containing or consisting of SEQ ID NO:

51.

12. A pharmaceutical composition comprising an anti-human λ light chain antibody or a human λ light chain conjugate fragment according to any one of claims 1 to 11, and a pharmaceutically acceptable excipient, diluent, or carrier.

13. A nucleic acid encoding an anti-human λ light chain antibody or a human λ light chain binding fragment according to any one of claims 1 to 11.

14. A host cell comprising a nucleic acid encoding the anti-human λ light chain antibody or a human λ light chain binding fragment according to any one of claims 1 to 11.

15. A method for producing an anti-human λ light chain antibody or a human λ light chain conjugate fragment according to any one of claims 1 to 11, (a) A step of incubating cells or cell lines containing nucleic acids encoding the anti-human λ light chain antibody or a human λ light chain binding fragment in a cell culture medium, wherein the cells or cell line express and secrete the anti-human λ light chain antibody or a human λ light chain binding fragment, (b) A step of collecting the anti-human λ light chain antibody or the human λ light chain binding fragment from the cell culture medium. A method that includes this.

16. A composition for use in a method for increasing the clearance of λ light chain aggregates, wherein the method comprises the step of contacting the λ light chain aggregates with an anti-human λ light chain antibody or a human λ light chain binding fragment according to any one of claims 1 to 11.

17. A pharmaceutical composition comprising an anti-human λ light chain antibody or a human λ light chain binding fragment according to any one of claims 1 to 11, for use in the treatment of a disease or illness characterized by λ light chain aggregates, wherein the treatment comprises reducing the number of λ light chain aggregates in the subject by administering the pharmaceutical composition to the subject.

18. The pharmaceutical composition according to claim 17, wherein the subject is suffering from plasma cell dysplasia.

19. The pharmaceutical composition according to claim 18, wherein the plasma cell dysplasia is selected from monoclonal immunoglobulinemia of unknown significance (MGUS), multiple myeloma (MM), plasma cell leukemia (PCL), and any combination thereof.

20. The pharmaceutical composition according to claim 17, wherein the subject is suffering from systemic amyloidosis or AL amyloidosis.

Images