FIELD OF THE INVENTION

This application relates to novel compositions of binding agents and carrier proteins and methods of making and using the same, in particular, as a cancer therapeutic.

BACKGROUND

Chemotherapy remains a mainstay for systemic therapy for many types of cancer, including melanoma. Most chemotherapeutic agents are only slightly selective to tumor cells, and toxicity to healthy proliferating cells can be high (Allen T M. (2002)Cancer2:750-763), often requiring dose reduction and even discontinuation of treatment. In theory, one way to overcome chemotherapy toxicity issues as well as improve drug efficacy is to target the chemotherapy drug to the tumor using antibodies that are specific for proteins selectively expressed (or overexpressed) by cancer cells to attract targeted drugs to the tumor, thereby altering the biodistribution of the chemotherapy and resulting in more drug going to the tumor and less affecting healthy tissue. Despite 30 years of research, however, specific targeting rarely succeeds in the therapeutic context.

Conventional antibody dependent chemotherapy (ADC) is designed with a toxic agent linked to a targeting antibody via a synthetic protease-cleavable linker. The efficacy of such ADC therapy is dependent on the ability of the target cell to bind to the antibody, the linker to be cleaved, and the uptake of the toxic agent into the target cell. Schrama, D. et al. (2006)Nature reviews. Drug discovery5:147-159.

Antibody-targeted chemotherapy promised advantages over conventional therapy because it provides combinations of targeting ability, multiple cytotoxic agents, and improved therapeutic capacity with potentially less toxicity. Despite extensive research, clinically effective antibody-targeted chemotherapy remains elusive: major hurdles include the instability of the linkers between the antibody and chemotherapy drug, reduced tumor toxicity of the chemotherapeutic agent when bound to the antibody, and the inability of the conjugate to bind and enter tumor cells. In addition, these therapies did not allow for control over the size of the antibody-drug conjugates.

There remains a need in the art for antibody-based cancer therapeutics that retain cytotoxic effect for targeted drug delivery to provide reliable and improved anti-tumor efficacy over prior therapeutics.

SUMMARY

According to the present invention are disclosed nanoparticles which contain (a) carrier protein, (b) optionally a binding agent, and (c) paclitaxel, wherein the paclitaxel is present in an amount that is less than an amount that provides a therapeutic effect, and optionally (d) a therapeutic agent. Some aspects of the current invention are predicated, in part, on the idea that a reduced amount of paclitaxel, for example compared to that in albumin-bound nanoparticles such as ABRAXANE®, facilitates the formation of a complex of a carrier protein, such as albumin, with a binding agent, such as an antibody, to provide a stable nanoparticle. These nanoparticles may be referred to herein as “reduced toxicity nanoparticles” (RTP) or RTP complexes.

Also disclosed herein are nanoparticles which contain (a) carrier protein, (b) a paclitaxel derivative, the paclitaxel derivative having reduced toxicity compared to paclitaxel, and optionally (c) a binding agent and/or (d) a therapeutic agent.

Further described herein are nanoparticle compositions, and methods of making and using the nanoparticles.

In one aspect is provided a nanoparticle comprising albumin and a paclitaxel derivative, wherein the paclitaxel derivative is less toxic than paclitaxel. In one embodiment, the paclitaxel derivative is a Meerwein Product of Paclitaxel. In a preferred embodiment, the paclitaxel derivative is 20-acetoxy-4-deactyl-5-epi-20, O-secotaxol. In one embodiment, the paclitaxel derivative is Baccatin III ((2β,5α,7α,10α,13β)-4,10-Diacetoxy-1,7,13-trihydroxy-9-oxo-5,20-epoxytax-11-en-2-yl benzoate). In one embodiment, the nanoparticle is held together by non-covalent bonds between the albumin and the paclitaxel derivative. In one embodiment, the albumin and the paclitaxel derivative have a relative weight ratio of less than about 10:1. In one embodiment, the nanoparticles do not comprise paclitaxel.

In one embodiment is provided a nanoparticle complex comprising albumin and a paclitaxel derivative, and further comprises binding agents (e.g., antibodies) having an antigen-binding domain. In one embodiment, an amount of the binding agents (e.g., antibodies) are arranged on an outside surface of the nanoparticle complexes. In some embodiments, the binding agents are a substantially single layer of binding agents on all or part of the surface of the nanoparticle. In one embodiment, the binding agents are bound to the carrier protein by non-covalent bonds. Preferably, the binding agents are antibodies.

In one embodiment, the nanoparticle complex further comprises a therapeutic agent. In one embodiment, the therapeutic agent is abiraterone, bendamustine, bortezomib, carboplatin, cabazitaxel, cisplatin, chlorambucil, dasatinib, docetaxel, doxorubicin, epirubicin, erlotinib, etoposide, everolimus, gefitinib, idarubicin, imatinib, hydroxyurea, imatinib, lapatinib, leuprorelin, melphalan, methotrexate, mitoxantrone, nedaplatin, nilotinib, oxaliplatin, paclitaxel, pazopanib, pemetrexed, picoplatin, romidepsin, satraplatin, sorafenib, vemurafenib, sunitinib, teniposide, triplatin, vinblastine, vinorelbine, vincristine, or cyclophosphamide. In one embodiment, the therapeutic agent is an agent listed in Table 2.

In one aspect is provided a nanoparticle composition comprising the nanoparticles or nanoparticle complexes as described herein.

In one aspect is provided a nanoparticle comprising a carrier protein (e.g., albumin) and paclitaxel, wherein the paclitaxel is present in an amount that is less than an amount that provides a therapeutic effect. In one embodiment, the nanoparticle is held together by non-covalent bonds between the carrier protein and the paclitaxel. In one aspect, the nanoparticle complex was made by combining the carrier protein (e.g., albumin) and paclitaxel at a relative weight ratio of greater than about 10:1 carrier protein to paclitaxel.

In one embodiment, the amount of paclitaxel present in the nanoparticles (nanoparticle complexes) or nanoparticle composition is greater than or equal to a minimum amount capable of providing stability to the nanoparticle complexes comprising a protein carrier (e.g., albumin) and paclitaxel. In one embodiment, the amount of paclitaxel present in the nanoparticles or nanoparticle composition is greater than or equal to a minimum amount capable of providing affinity of the paclitaxel with the protein carrier (e.g., albumin). In one embodiment, the amount of paclitaxel present in the nanoparticles or nanoparticle composition is greater than or equal to a minimum amount capable of facilitating complex formation of the paclitaxel and the protein carrier (e.g., albumin).

The ratio of albumin to paclitaxel in the nanoparticles or nanoparticle composition preferably is less than that present in ABRAXANE®. ABRAXANE® contains 100 mg paclitaxel for about 900 mg albumin. In one embodiment, the weight ratio of the carrier protein (e.g., albumin) to paclitaxel in the nanoparticle composition is greater than about 9:1. In one embodiment, the weight ratio is greater than about 10:1, or 11:1, or 12:1, or 13:1, or 14:1, or 15:1, or about 16:1, or about 17:1, or about 18:1, or about 19:1, or about 20:1, or about 21:1, or about 22:1, or about 23:1, or about 24:1, or about 25:1, or about 26:1, or about 27:1, or about 28:1, or about 29:1, or about 30:1. In one embodiment, the weight ratio of the carrier protein to paclitaxel in the nanoparticle complex is greater than about 9:1. In one embodiment, the weight ratio is greater than about 10:1, or 11:1, or 12:1, or 13:1, or 14:1, or 15:1, or about 16:1, or about 17:1, or about 18:1, or about 19:1, or about 20:1, or about 21:1, or about 22:1, or about 23:1, or about 24:1, or about 25:1, or about 26:1, or about 27:1, or about 28:1, or about 29:1, or about 30:1.

In one embodiment, the amount of paclitaxel is greater than or equal to a minimum amount capable of providing stability to the nanoparticle complexes comprising a protein carrier (e.g., albumin) and paclitaxel, and optionally at least one therapeutic agent. In one embodiment, the amount of paclitaxel is greater than or equal to a minimum amount capable of providing affinity of the at least one therapeutic agent to the protein carrier. In one embodiment, the amount of paclitaxel is greater than or equal to a minimum amount capable of facilitating complex formation of the at least one therapeutic agent and the protein carrier.

In any of the embodiments, the amount of paclitaxel can be less than a therapeutic amount for paclitaxel. In other words, the amount can be less than what is provided or contemplated for providing a therapeutic benefit, such as for example, a chemotherapeutic amount to effectively treat a cancer.

In one embodiment, the amount of paclitaxel present in the nanoparticle composition is less than about 5 mg/mL. In one embodiment, the amount of paclitaxel present in the nanoparticle composition is less than about 4.54 mg/mL, or about 4.16 mg/mL, or about 3.57 mg/mL, or about 3.33 mg/mL, or about 3.12 mg/mL, or about 2.94 mg/mL, or about 2.78 mg/mL, or about 2.63 mg/mL, or about 2.5 mg/mL, or about 2.38 mg/mL, or about 2.27 mg/mL, or about 2.17 mg/mL, or about 2.08 mg/mL, or about 2 mg/mL, or about 1.92 mg/mL, or about 1.85 mg/mL, or about 1.78 mg/mL, or about 1.72 mg/mL, or about 1.67 mg/mL.

Without being bound by theory, it is contemplated that binding to the carrier protein, e.g., complexation of the binding agent to the carrier protein, occurs through an albumin-binding motif on the binding agents and/or an antibody-binding motif on the carrier protein. In one embodiment, the binding agent comprises an albumin-binding motif. In one embodiment, the carrier protein comprises an antibody-binding motif. Non-limiting examples of antibody-binding motifs can be found in PCT Application No. PCT/US2017/045643, filed Aug. 4, 2017, which is incorporated herein by reference in its entirety. In some embodiments, the binding agent is a non-therapeutic and non-endogenous human antibody, a fusion protein, e.g., fusion of an antibody Fc domain to a peptide that binds a target antigen, or an aptamer.

In one embodiment, the binding agent comprises an antigen-binding domain. In one embodiment, the antigen is CD3, CD19, CD20, CD38, CD30, CD33, CD52, PD-1, PD-L1, PD-L2, CTLA-4, RANK-L, GD-2, Ly6E, HER3, EGFR, DAF, ERBB-3 receptor, CSF-1R, HER2, STEAP1, CD3, CEA, CD40, OX40, Ang2-VEGF, or VEGF.

Tin one embodiment, the binding agent is an antibody selected from ado-trastuzumab emtansine, alemtuzumab, atezolizumab, bevacizumab, cetuximab, denosumab, dinutuximab, ipilimumab, nivolumab, obinutuzumab, ofatumumab, panitumumab, pembrolizumab, pertuzumab, rituximab, Ramucirumab, avelumab or durvalumab, pidilizumab, BMS 936559, OKT3, and trastuzumab.

The invention further includes lyophilized nanoparticles and nanoparticle compositions, and lyophilized nanoparticles and compositions that do not materially differ from, or are the same as, the properties of freshly-prepared nanoparticles. In particular, the lypholized composition, upon resuspending in aqueous solution, is similar or identical to the fresh composition in terms of particle size, particle size distribution, toxicity for cancer cells, binding agent affinity, and binding agent specificity. Surprisingly, lyophilized nanoparticles retain the properties of freshly-made nanoparticles after resuspension, notwithstanding the presence of two different protein components in these particles. In one embodiment, the lyophilized composition is stable at room temperature for at least about 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or longer. In one embodiment, the lyophilized composition is stable at room temperature for at least 3 months. In one embodiment, the reconstituted nanoparticles retain the activity of the therapeutic agent and are capable of binding to the target in vivo.

In some embodiments, the at least one therapeutic agent is located inside the nanoparticle. In other embodiments, the at least one therapeutic agent is located on the outside surface of the nanoparticle. In yet other embodiments, the at least one therapeutic agent is located inside the nanoparticle and on the outside surface of the nanoparticle.

In some embodiments, the nanoparticle contains more than one type of therapeutic agent. For example, a taxane and a platinum drug, e.g. paclitaxel and cisplatin.

In some embodiments, the nanoparticle further comprises at least one additional therapeutic agent that is not paclitaxel. In some embodiments, the at least one therapeutic agent is abiraterone, bendamustine, bortezomib, carboplatin, cabazitaxel, cisplatin, chlorambucil, dasatinib, docetaxel, doxorubicin, epirubicin, erlotinib, etoposide, everolimus, gefitinib, idarubicin, imatinib, hydroxyurea, imatinib, lapatinib, leuprorelin, melphalan, methotrexate, mitoxantrone, nedaplatin, nilotinib, oxaliplatin, pazopanib, pemetrexed, picoplatin, romidepsin, satraplatin, sorafenib, vemurafenib, sunitinib, teniposide, triplatin, vinblastine, vinorelbine, vincristine, or cyclophosphamide.

In some embodiments, the binding agents, carrier protein and/or, when present, therapeutic agent, are bound through non-covalent bonds.

In some embodiments, the carrier protein is selected from the group consisting of gelatin, elastin, gliadin, legumin, zein, a soy protein, a milk protein, and a whey protein. In preferred embodiments, the carrier protein is albumin, for example, human serum albumin.

In some embodiments, the composition is formulated for intravenous delivery. In other embodiments, the composition is formulated for direct injection or perfusion into a tumor.

In some embodiments, the nanoparticles have a dissociation constant between about 1×10−11M and about 1×10−9M.

In one embodiment, provided herein are methods of making the nanoparticle compositions, wherein said method comprises contacting the carrier protein and the paclitaxel and the at least one therapeutic agent under conditions and ratios of components that will allow for formation of the desired nanoparticles.

In some aspects, provided herein are methods for forming an albumin-paclitaxel derivative or albumin-paclitaxel nanoparticle, wherein method comprises: homogenizing the albumin with paclitaxel derivative or paclitaxel in a solution under high pressure, to generate an albumin-paclitaxel derivative or albumin-paclitaxel nanoparticle.

In some aspects, provided herein are methods of making nanoparticle compositions, wherein said methods comprise contacting the carrier protein, the paclitaxel, and/or the therapeutic agent with the binding agents in a solution having a pH of between 5.0 and 7.5 and a temperature between about 5° C. and about 60° C., between about 23° C. and about 60° C., or between about 55° C. and about 60° C. under conditions and ratios of components that will allow for formation of the desired nanoparticles. In one embodiment, the nanoparticle is made between 55° C. and 60° C. and pH 7.0. In another aspect, provided herein are methods of making the nanoparticle compositions, wherein said method comprises (a) contacting the carrier protein, the paclitaxel and the therapeutic agent to form a core and (b) optionally contacting the core with the antibodies in a solution having a pH of about 5.0 to about 7.5 at a temperature between about 5° C. and about 60° C., between about 23° C. and about 60° C., or between about 55° C. and about 60° C. under conditions and ratios of components that will allow for formation of the desired nanoparticles.

In some aspects, an amount of a therapeutic agent (e.g., a therapeutic agent which is not paclitaxel) can also be added to the carrier protein.

In further embodiments, the nanoparticles are made as above, and then lyophilized.

In another aspect, provided herein are methods for treating a cancer cell, the method comprising contacting the cell with an effective amount of a nanoparticle composition disclosed herein to treat the cancer cell.

In one embodiment is provided a method for killing cancer cells in a population of cancer cells, the method comprising contacting the cells with an effective amount of a nanoparticle composition, wherein said composition is maintained in contact with said cells for a sufficient period of time to kill cancer cells, wherein said nanoparticle composition comprises nanoparticle complexes, each of the nanoparticles comprising albumin and paclitaxel, wherein the paclitaxel is present in an amount that is less than an amount that provides a therapeutic effect.

In one embodiment is provided a method for treating cancer in patient in need thereof, the method comprising administering to the patient a nanoparticle composition comprising nanoparticle complexes, each of the nanoparticles comprising albumin and paclitaxel, wherein the paclitaxel is present in an amount that is less than an amount that provides a therapeutic effect.

In another aspect, provided herein are methods for treating a tumor in a patient in need thereof, the method comprising contacting the cell with an effective amount of a nanoparticle composition disclosed herein to treat the tumor. In some embodiments, the size of the tumor is reduced. In other embodiments, the nanoparticle composition is administered intravenously. In yet other embodiments, the nanoparticle composition is administered by direct injection or perfusion into the tumor.

In some embodiments, the methods provided herein include the steps of: a) administering the nanoparticle composition once a week for three weeks; b) ceasing administration of the nanoparticle composition for one week; and c) repeating steps a) and b) as necessary to treat the tumor.

In some embodiments, the therapeutically effective amount comprises about 75 mg/m2to about 175 mg/m2of the carrier protein (i.e., milligrams carrier protein per m2of the patient). In other embodiments, the paclitaxel is of an amount that is less than about 75 mg/m2, such as between 5 mg/m2and 75 mg/m2. In other embodiments, the paclitaxel is of an amount that is less than a therapeutically effective amount. In some embodiments, the therapeutic agent is of a therapeutically effective amount. In some embodiments, the therapeutically effective amount comprises about 30 mg/m2to about 70 mg/m2of the binding agent. In yet other embodiments, the therapeutically effective amount comprises about 30 mg/m2to about 70 mg/m2bevacizumab.

An embodiment of the invention includes a method for increasing the duration of tumor uptake of a chemotherapeutic agent by administering the chemotherapeutic agent in a nanoparticle comprising a carrier protein and the chemotherapeutic agent having surface complexation with an antibody, e.g., an antibody that specifically binds to an antigen on or shed by the tumor.

