scholarly journals Preclinical Development of a Bcma Targeting Antibody-Drug Conjugate with Novel Payload for Multiple Myeloma Therapy

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5623-5623
Author(s):  
Andrew Hau ◽  
Tong Zhu ◽  
Rengang Wang ◽  
Megan Lau ◽  
Lingna Li ◽  
...  

BCMA (B-cell maturation antigen) is an integral membrane protein that belongs to the TNF receptor family with expression restricted to B cell lineage cells. The RNA is near universally detected in multiple myeloma (MM) cells and the protein is expressed on the surface of malignant plasma cells from patients with MM. In contrast, BCMA expression in normal tissues is very limited, making BCMA a promising target for antibody-drug conjugate (ADC) therapy. We have developed a BCMA-targeting ADC, employing a fully human anti-BCMA monoclonal antibody (mAb) identified from Sorrento's G-MAB antibody library, which was conjugated using proprietary Concortis linker-Duo 5.2 toxin technology resulting in BCMA-077 ADC. The mAb has a unique binding profile for BCMA and demonstrated strong preferential binding for BCMA-overexpressing cells but showed much less binding to lower BCMA-expressing cells. This property allows for more selective binding of the ADC on high BCMA-expressing cells, which are usually tumor cells while sparing low BCMA-expressing normal cells. In addition, we modified the Duo 5.2 payload decreasing the potency of the unconjugated toxin while retaining activity when conjugated to the mAb. The resulting ADC, BCMA-024, was compared to BCMA-077 using in vitro assays, including binding, internalization and cytotoxicity against tumor cell lines. The two ADCs exhibited strong activity and no difference in cytotoxic potency evident. The toxicity of the payload derivative was evaluated in a rodent model and it was found to be well tolerated not showing toxicity at a dose 10 times higher than the lethal dose of the parental toxin. Both ADCs carrying either the parental Duo 5.2 toxin or the derivative toxin payload were evaluated in vivo for anti-tumor activity in three different multiple myeloma xenograft models using different dose regimens. The data showed that both ADCs demonstrated potent BCMA-dependent in vivo anti-tumor activity in all xenograft BCMA-positive tumor models. The PK of the parental anti-BCMA mAb was investigated in non-human primates (NHP) and the parameters indicated a T1/2 of about 10 days. The GLP toxicity studies are ongoing. Our BCMA-ADCs have shown favorable anti-tumor activities combined with good safety profiles resulting in an expanded therapeutic window. The data make BCMA-077 and BCMA-024 promising candidates for continued preclinical development. Based on the totality of our preclinical data, we anticipate selecting a BCMA ADC clinical candidate for the treatment of multiple myeloma. Disclosures Hau: Concortis Biotherapeutics: Employment, Equity Ownership. Zhu:Levena Biopharma: Employment, Equity Ownership, Patents & Royalties. Wang:Concortis Biotherapeutics: Employment, Equity Ownership. Lau:Levena Biopharma: Employment, Equity Ownership. Li:Concortis Biotherapeutics: Employment, Equity Ownership. Li:Levena Biopharma: Employment, Equity Ownership. Sun:Levena Biopharma: Employment, Equity Ownership. Kovacs:Levena Biopharma: Employment, Equity Ownership. Khasanov:Levena Biopharma: Employment, Equity Ownership. Deng:Levena Biopharma: Employment, Equity Ownership. Yan:Levena Biopharma: Employment, Equity Ownership. Knight:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Kaufmann:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Ji:Sorrento Therapeutics Inc: Employment, Equity Ownership, Patents & Royalties; Celularity, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Li:Levena Biopharma: Employment, Equity Ownership, Patents & Royalties; Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Zhang:Concortis Biotherapeutics: Employment, Equity Ownership, Patents & Royalties.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5621-5621 ◽  
Author(s):  
Lingna Li ◽  
Wenyong Tong ◽  
Megan Lau ◽  
Katherine Fells ◽  
Tong Zhu ◽  
...  

CD38 is a validated target for the treatment of multiple myeloma (MM). Daratumumab (Darzalex®), an anti-CD38 monoclonal antibody (mAb), has shown great clinical efficacy and has been approved for multiple myeloma treatment. However, both primary refractoriness and development of resistance to daratumumab therapy have been reported. Based on the therapeutic benefits of this CD38 antibody, we developed a CD38-targeting antibody-drug conjugate (ADC), employing a fully human anti-CD38 antibody STI-6129, identified from Sorrento's G-MAB® antibody library, and proprietary linker-toxin technology. The toxin payload is duostatin 5.2 (Duo.5.2), a microtubule inhibitor, conjugated to STI-6129 via a non-polyethylene glycol linker resulting in our lead ADC CD38-077. Cell binding studies showed that it specifically binds to CD38-positive tumor cells but not CD38-negative cell lines. The cell binding was proportional to the CD38 expression level on the cell surface. The ADC was internalized into CD38-positive cells at a rate comparable to that of the unconjugated antibody, indicating that conjugation did not change the binding characteristics of STI-6129 to its antigen. In cytotoxicity studies, CD38-077 exhibited a CD38-dependent cytotoxic activity against a panel of CD38-expressing tumor cell lines and was more potent in cells with high CD38 expression. The cytotoxic effect of CD38-077 was also examined against human PBMC cells, as it has been reported that certain types of the immune cells express CD38. The result indicated that normal PBMC cells were generally insensitive to the ADC up to 1 µM following 120 hr exposure. We investigated the anti-tumor activity of CD38-077 in xenograft animal models of Burkitt's lymphoma and two different multiple myeloma (MM) cell lines. The studies evaluated different dose levels and dosing regimens, including single dose and multiple doses at various intervals. The data showed that the ADC has a broad, potent and CD38-dependent in vivo efficacy in all three xenograft tumor models examined. In a pharmacokinetic study in naïve mice, CD38-077 was found to be stable, with T1/2 of about 7-11 days, comparable to that of the unconjugated STI-6129 antibody. In summary, CD38-077 exhibits strong anti-tumor activity in vitro and in vivo. The ADC showed specific activity towards CD38-expressing tumors but was less active against CD38-expressing normal PBMC cells, which express relatively low levels of CD38 level and where internalization was not detectable. These results warrant further development exploration of CD38-077. Disclosures Li: Concortis Biotherapeutics: Employment, Equity Ownership. Lau:Levena Biopharma: Employment, Equity Ownership. Fells:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Zhu:Levena Biopharma: Employment, Equity Ownership, Patents & Royalties. Sun:Levena Biopharma: Employment, Equity Ownership. Kovacs:Levena Biopharma: Employment, Equity Ownership. Khasanov:Levena Biopharma: Employment, Equity Ownership. Yan:Levena Biopharma: Employment, Equity Ownership. Deng:Levena Biopharma: Employment, Equity Ownership. Takeshita:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Kaufmann:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Ji:Sorrento Therapeutics Inc: Employment, Equity Ownership, Patents & Royalties; Celularity, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Li:Levena Biopharma: Employment, Equity Ownership, Patents & Royalties; Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Zhang:Concortis Biotherapeutics: Employment, Equity Ownership, Patents & Royalties.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 877-877
Author(s):  
Yu-Tzu Tai ◽  
Chirag Acharya ◽  
Mike Y Zhong ◽  
Michele Cea ◽  
Antonia Cagnetta ◽  
...  

Abstract B cell maturation antigen (BCMA), which is highly expressed on malignant plasma cells in human multiple myeloma (MM), has not been effectively targeted with therapeutic monoclonal antibodies (mAbs). We here investigated the anti-MM activity of J6M0-mcMMAF (GSK2857916), a humanized and afucosylated anti-BCMA antibody-drug conjugate (ADC) via uncleavable linker. This novel antagonist anti-BCMA antibody shows binding against all CD138-expressing MM cell lines (n=13) and patient MM cells (n=18), confirming universal BCMA expression on the surface of myeloma cells. Real-time qRT-PCR also showed significantly upregulated BCMA mRNA in CD138+ cells purified from MM patients vs. normal donors (p < 0.03). In contrast, BCMA is undetectable in CD138-negative cells from MM patients (n=3). J6M0-mcMMAF strongly blocks cell growth and induces caspase 3-dependent apoptosis in both drug-sensitive and -resistant MM cell lines and patient CD138+ MM cells, alone and in co-culture with BMSCs. In contrast, an isotype control antibody-drug conjugate (iso-mcMMAF) had no effect on viability of ANBL6 MM cells, alone or cocultured with BMSC. J6M0-mcMMAF specifically induces cell death in CD138-positive patient MM cells but not CD138-negative cells, demonstrating the minimal bystander killing against surrounding BCMA-negative cells. J6M0-mcMMAF completely blocks colony formation of MM cell lines (n=6) via induction of G2/M arrest, followed by apoptosis. This ADC does not affect viability of BCMA-negative NK, PBMC, and BMSCs, cultured alone or together, confirming its specific targeting of BCMA-positive MM cells. J6M0-mcMMAF, which has enhanced Fc-receptor binding due to afucosylation, significantly improved autologous antibody-dependent cellular cytotoxicity (ADCC) potency and maximum MM cell lysis against MM patient cells (n=5), when compared to J6M0 with normal Fc. Such augmented ADCC and maximum patient MM cell lysis by J6M0-mcMMAFis more pronounced in the autologous setting vs. the allogenic setting where MM cells and healthy donor effectors were used. Pretreatment of PBMC effector cells with lenalidomide further increased J6M0-mcMMAF-induced ADCC against MM cells in the presence or absence of BMSC. The in vivo efficacy of J6M0-mcMMAF was evaluated in murine subcutaneous xenograft models using NCI-H929 and OPM2 cells, as well as in NK-deficient SCID-beige mice with diffuse human MM bone lesions using MM1Sluc cells. Administration of J6M0-mcMMAF at 4 mg/kg (q3d x 4, ip) completely eliminated NCI-H929 and OPM2 xenograft tumors in all mice which remained tumor-free until the termination of studies at 60 and 100 days, respectively. In the MM1Sluc bone marrow dissemination model, J6M0-mcMMAF eradicates detectable tumors after 2 doses at 0.4 mg/kg (q3d x 9, ip), which resulted in extended survival (p<0.0001) and no weight loss of mice following 120 days. J6M0 treatment, although less effective than J6M0-mcMMAF, also had significantly prolonged survival (p<0.03) and diminished tumor burden when compared with control vehicle and isotype-treated groups, indicating a potential role of macrophage-mediated phagocytosis. Indeed, J6M0-mcMMAF recruits macrophage and mediates phagocytosis of target MM cells. Taken together, our studies show that J6M0-mcMMAF potently and selectively induce direct and indirect killing of MM tumor cells both in vitro and in vivo, providing a very promising next-generation immunotherapeutic in this cancer. Disclosures: Tai: Onyx: Consultancy. Mayes:GlaxoSmithKline: Employment. Craigen:GlaxoSmithKline: Employment. Gliddon:GlaxoSmithKline: Employment. Smothers:GlaxoSmithKline: Employment. Richardson:Millenium: Consultancy; Celgene: Consultancy; Johnson & Johnson: Consultancy; Bristol-Myers Squibb: Consultancy; Novartis: Consultancy. Munshi:Celgene: Consultancy; Novartis: Consultancy; Millennium: Consultancy. Anderson:celgene: Consultancy; onyx: Consultancy; gilead: Consultancy; sanofi aventis: Consultancy; oncopep: Equity Ownership; acetylon: Equity Ownership.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1437-1437 ◽  
Author(s):  
Uma Borate ◽  
Amir T. Fathi ◽  
Bijal D. Shah ◽  
Daniel J. DeAngelo ◽  
Lewis B. Silverman ◽  
...  

Abstract Background CD19, a member of the immunoglobulin superfamily, is a B-cell specific marker that is found on B cells as early as the pro-B cell stage. CD19 is maintained upon malignant transformation and is expressed in the majority of patients with B-lineage leukemia and non-Hodgkin lymphoma (NHL). SGN-CD19A is a novel antibody-drug conjugate composed of a humanized anti-CD19 monoclonal antibody conjugated to the microtubule-disrupting agent monomethyl auristatin F (MMAF) via a maleimidocaproyl (mc) linker. Upon binding to CD19, SGN-CD19A internalizes and releases cys-mcMMAF, which binds to tubulin and induces G2/M arrest and apoptosis in the targeted cells. Methods A first-in-human, phase 1, open-label, dose-escalation study has been initiated to investigate the safety, tolerability, pharmacokinetics (PK), and antitumor activity of SGN-CD19A in adult and pediatric patients with relapsed or refractory (R/R) B-cell leukemia or highly aggressive B-cell lymphoma (CT.gov NCT01786096). Eligible patients must have a pathologically confirmed diagnosis of B-cell acute leukemia (B-ALL), Burkitt leukemia or lymphoma, or B-cell lymphoblastic lymphoma (B-LBL), and be R/R to at least 1 (adults) or 2 (pediatric) prior systemic regimens. A modified continual reassessment method is being used for dose allocation and maximum tolerated dose (MTD) estimation. SGN-CD19A is administered IV on Days 1 and 8 of 21-day cycles at up to 7 cohort-specific doses (0.3–2.3 mg/kg). Results Thirteen patients (11 adults, 2 pediatric) with R/R leukemia (9 B-ALL) or lymphoma (3 B-LBL, 1 Burkitt lymphoma) have been treated in this ongoing study. Adults (73% female) have a median age of 60 years (range, 26–74) and have received a median of 2 prior systemic therapies (range, 1–6). Four of the 11 adults (36%) have also received an allogeneic stem cell transplant (SCT). The pediatric patients, 2 females 13-and 14-years-old, have each received 3 prior systemic therapies; one of the pediatric patients has also received 2 allogeneic SCTs. To date, patients have been treated at 0.3 mg/kg (2 patients), 0.6 mg/kg (3 patients), 1.0 mg/kg (3 patients), and 1.3 mg/kg (5 patients). The maximum number of cycles received by a patient is 7. Four patients remain on treatment and 9 patients have discontinued treatment (7 due to progressive disease, 1 because of investigator decision, and 1 due to death). One patient with B-ALL treated at 1.0 mg/kg developed cardiac arrest in the setting of pre-existing electrolyte abnormalities and died 7 days after the first dose of SGN-CD19A; although this event was considered unrelated to study drug by the investigator, a possible relationship could not be excluded due to temporal association. Treatment-emergent adverse events reported for ≥10% of adult patients were nausea (64%); fatigue and pyrexia (55% each); chills (36%); headache (27%); and dyspnea, hypertension, oral pain, thrombocytopenia, tumor lysis syndrome, and vomiting (18% each). Drug-related AEs in adult patients were pyrexia (55%); nausea (45%); chills (36%); fatigue (27%); and headache, oral pain, and blurred vision (9% each). Drug-related AEs reported for the pediatric patients were abdominal pain, cough, diarrhea, dyspepsia, hyperuricemia, nausea, peripheral neuropathy, pruritus, pyrexia, tachycardia, and urticaria (all Grade 1 or 2, each in one patient). Preliminary data demonstrate rapid clearance of antibody-drug conjugate at low doses in patients with leukemia, suggesting target-mediated drug disposition. To date, best responses for patients with lymphoma are stable disease (2 patients) and progressive disease (2 patients). Best responses for the 8 leukemia patients with available response assessments are complete remission (1 adult at 1.3 mg/kg); resistant disease with clinical benefit, i.e., improvement in leukemia-related symptoms (4 patients); and progressive disease (3 patients). Conclusions MTDs have not yet been identified for adult or pediatric patients and dose-escalation continues in both populations. Antitumor activity has been observed, including 1 complete remission in a heavily pretreated B-ALL patient. Nonlinear clearance of the antibody-drug conjugate in leukemia patients suggests target-mediated disposition. Updated safety, PK, and response data will be presented at the meeting. A second trial is evaluating SGN-CD19A every 3 weeks in aggressive B-cell NHL (CT.gov NCT01786135). Disclosures: Borate: Seattle Genetics, Inc.: Research Funding; Genoptix: Consultancy. Fathi:Millennium: Research Funding; Seattle Genetics, Inc.: Advisory/Scientific board membership Other, Research Funding; Agios: Membership on an entity’s Board of Directors or advisory committees; Teva: Membership on an entity’s Board of Directors or advisory committees. Shah:Seattle Genetics, Inc.: Research Funding; NCCN: Membership on an entity’s Board of Directors or advisory committees; SWOG: Membership on an entity’s Board of Directors or advisory committees; Celgene: Speakers Bureau; Janssen/Pharmacyclics: Speakers Bureau. DeAngelo:Seattle Genetics, inc.: Research Funding. Silverman:Seattle Genetics, Inc.: Advisory/scientific board membership Other. Cooper:Seattle Genetics, Inc.: Research Funding. Albertson:Seattle Genetics, Inc.: Employment, Equity Ownership. O'Meara:Seattle Genetics, Inc.: Employment, Equity Ownership. Sandalic:Seattle Genetics, Inc.: Employment, Equity Ownership. Stevison:Seattle Genetics, Inc.: Employment, Equity Ownership. Chen:Seattle Genetics, Inc.: Consultancy, Research Funding, Speakers Bureau, Travel expenses Other.


2016 ◽  
Vol 174 (6) ◽  
pp. 911-922 ◽  
Author(s):  
Lydia Lee ◽  
Danton Bounds ◽  
Jennifer Paterson ◽  
Gaelle Herledan ◽  
Katherine Sully ◽  
...  

Haematologica ◽  
2020 ◽  
Vol 105 (11) ◽  
pp. 2584-2591 ◽  
Author(s):  
Eugenio Gaudio ◽  
Chiara Tarantelli ◽  
Filippo Spriano ◽  
Francesca Guidetti ◽  
Giulio Sartori ◽  
...  

Antibody drug conjugates represent an important class of anti-cancer drugs in both solid tumors and hematological cancers. Here, we report preclinical data on the anti-tumor activity of the first-in-class antibody drug conjugate MEN1309/OBT076 targeting CD205. The study included preclinical in vitro activity screening on a large panel of cell lines, both as single agent and in combination and validation experiments on in vivo models. CD205 was first shown frequently expressed in lymphomas, leukemias and multiple myeloma by immunohistochemistry on tissue microarrays. Anti-tumor activity of MEN1309/OBT076 as single agent was then shown across 42 B-cell lymphoma cell lines with a median IC50 of 200 pM and induction of apoptosis in 25/42 (59.5%) of the cases. The activity appeared highly correlated with its target expression. After in vivo validation as the single agent, the antibody drug conjugate synergized with the BCL2 inhibitor venetoclax, and the anti-CD20 monoclonal antibody rituximab. The first-in-class antibody drug targeting CD205, MEN1309/OBT076, demonstrated strong pre-clinical anti-tumor activity in lymphoma, warranting further investigations as a single agent and in combination.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1942-1942 ◽  
Author(s):  
Bei Bei Ding ◽  
John Dixon Gray ◽  
Nan Zhang ◽  
Yanliang Zhang ◽  
Xia Cao ◽  
...  

Background: Multiple myeloma remains an incurable malignancy of plasma cells. Adoptive transfer of chimeric antigen receptor (CAR)-expressing T cells is a promising new therapy for hematologic malignancies. B-cell maturation antigen (BCMA) is a protein that is selectively expressed by B-lineage cells, including Multiple Myeloma (MM) cells, and represents a suitable target for T cell therapy. We have developed an allogeneic T cell therapy approach utilizing genetic engineering of donor-derived T cells to express an anti-BCMA Dimeric Antigen Receptor (DAR) using a proprietary non-viral vector Knock out/knock in (KOKI) technology. Preclinical data demonstrate potent anti-tumor activity both vitro and in vivo against BCMA-expressing MM cell lines. Methods: Anti-BCMA DAR-T cells were generated through genetic engineering of T cells derived from healthy donors by inserting the anti-BCMA DAR construct into the TRAC gene locus, resulting in loss of endogenous TCR expression while expressing the DAR. Distinct DAR constructs were utilized differing only in their intracellular signaling components, namely combinations of 4-1BB, CD28, and CD3zeta. The anti-BCMA DAR-T cells were expanded and purified for subsequent preclinical studies. Using in vitro assays, the different anti-BCMA DAR-T cells were evaluated against multiple myeloma cell lines for specific cytotoxicity as well as stimulus-induced cytokine secretion and cell expansion. The in vivo anti-tumor activity was assessed using luciferase-expressing RPMI8226 cells in NSG mice in a model of disseminated disease. A single dose of anti-BCMA DAR-T cells or relevant control cells was administered, and tumor burden was assessed weekly using bioluminescence imaging. Results: After purification, the anti-BCMA DAR T cells population contained less than 1% TCR-expressing ab T cells. The DAR-positive T cell population was between 20-50%. All anti-BCMA DAR-T cells exhibited BCMA-specific activation, including cytokine production, proliferation, cytotoxicity, and in vivo tumor eradication. The DAR-T cells using a third generation signaling configuration containing components from 4-1BB, CD28 and CD3zeta signaling domains performed best overall. Conclusions: All tested anti-BCMA DAR-T cells exhibited effective anti-tumor activity. Direct comparison of different cytoplasmic signaling compositions of the DAR allowed for selection of the most potent construct, namely the anti-BCMA DAR utilizing a 3rd generation signaling domain configuration. Based on these data, further development of anti-BCMA DAR-T therapy for hematological malignancies is warranted. These allogeneic abTCR-negative anti-BCMA DAR-T cells have been selected for clinical development. Disclosures Ding: Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Gray:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Zhang:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Zhang:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Cao:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Krapf:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Deng:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Wei:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Zeldis:Sorrento Therapeutics Inc: Employment, Equity Ownership. Knight:Sorrento Therapeutics, Inc.: Employment, Equity Ownership. Kaufmann:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Ji:Sorrento Therapeutics Inc: Employment, Equity Ownership, Patents & Royalties; Celularity, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Guo:Sorrento Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-32
Author(s):  
Asma Jabeen ◽  
Shiran Huang ◽  
John A. Hartley ◽  
Patrick H Van Berkel ◽  
Francesca Zammarchi

Camidanlumab tesirine (ADCT-301) is an antibody-drug conjugate (ADC) comprised of HuMax®-TAC, a monoclonal antibody directed against human CD25, conjugated to the pyrrolobenzodiazepine dimer payload tesirine[1]. Currently, camidanlumab tesirine is being evaluated in a pivotal Phase 2 clinical trial in patients with relapsed or refractory Hodgkin lymphoma (HL) (NCT04052997) and in a Phase 1b clinical trial in patients with advanced solid tumors (NCT03621982). In pre-clinical studies, camidanlumab tesirine demonstrated strong and durable single agent activity in CD25-expressing lymphoma xenograft models[1] and in vitro it synergised with selected targeted agents[2]. Moreover, CD25-ADC, a mouse CD25 cross-reactive surrogate of camidanlumab tesirine, induced potent anti-tumor immunity against established syngeneic solid tumor models by depleting CD25-positive tumor-infiltrating T regulatory cells (Tregs) and it showed synergistic activity when combined with PD-1 blockade[3]. Here, we investigated the in vitro and in vivo anti-tumor activity of camidanlumab tesirine combined with gemcitabine, a common standard-of-care chemotherapeutic agent used both in a hematological and solid tumor clinical setting. In vitro, the combination of camidanlumab tesirine and gemcitabine was evaluated in three human-derived cancer cell lines (two HL and one anaplastic large cell lymphoma, ALCL) and resulted in synergistic activity as determined by the Chou-Talalay method. In vivo, camidanlumab tesirine was tested either alone (0.05 or 0.1 mg/kg, single dose) or in combination with gemcitabine (80 mg/kg, q3dx4) in the CD25-expressing ALCL Karpas299 xenograft model. At both ADC dose levels, combination with gemcitabine resulted in synergistic anti-tumor activity (coefficient of drug interaction (CDI) 0.51 and 0.17, respectively), better response rates and increased survival compared to monotherapy with camidanlumab tesirine. In order to extend the investigation to solid tumor models, CD25-ADC was tested in the CT26 syngeneic model, a colorectal cancer model with CD25-expressing tumor-infiltrating Tregs. CD25-ADC was administered either alone (0.1, 0.5 or 1 mg/kg, single dose) or in combination with gemcitabine (80 mg/kg, q3dx4). At the 0.1 mg/kg dose of CD25-ADC, combination with gemcitabine resulted in synergistic anti-tumor activity (CDI 0.68). Moreover, at 0.5 and 1 mg/kg, the combination of CD25-ADC and gemcitabine resulted in more durable anti-tumor activity and better response rates compared to both monotherapy treatments. In conclusion, the combination of camidanlumab tesirine and gemcitabine was synergistic both in vitro and in vivo in lymphoma preclinical models. Synergistic anti-tumor activity was also demonstrated in a colorectal cancer model using CD25-ADC, a mouse-cross-reactive version of camidanlumab tesirine, in combination with gemcitabine. Altogether, these novel pre-clinical data warrant translation of the combination between camidanlumab tesirine and gemcitabine into the clinic. 1.Flynn, M.J., et al., ADCT-301, a Pyrrolobenzodiazepine (PBD) Dimer-Containing Antibody-Drug Conjugate (ADC) Targeting CD25-Expressing Hematological Malignancies. Mol Cancer Ther, 2016. 15(11): p. 2709-2721. 2.Spriano, F., et al., The anti-CD25 antibody-drug conjugate camidanlumab tesirine (ADCT-301) presents a strong preclinical activity both as single agent and in combination in lymphoma cell lines. Hematological Oncology, 2019. 37(S2): p. 323-324. 3.Zammarchi, F., et al., A CD25-targeted antibody-drug conjugate depletes regulatory T cells and eliminates established syngeneic tumors via antitumor immunity. Journal for ImmunoTherapy of Cancer, 2020. In press. Disclosures Jabeen: ADC Therapeutics: Current Employment. Hartley:ADC Therapeutics: Consultancy, Current equity holder in publicly-traded company, Research Funding. Van Berkel:ADC-Therapeutics: Current Employment, Current equity holder in publicly-traded company. Zammarchi:ADC-Therapeutics: Current Employment, Current equity holder in publicly-traded company.


Sign in / Sign up

Export Citation Format

Share Document