-Author name in bold denotes the presenting author
-Asterisk * with author name denotes a Non-ASH member
Clinically Relevant Abstract denotes an abstract that is clinically relevant.

PhD Trainee denotes that this is a recommended PHD Trainee Session.

Ticketed Session denotes that this is a ticketed session.

3235 CD20 Targeted CAR-T for High-Risk B-Cell Non-Hodgkin Lymphomas

Program: Oral and Poster Abstracts
Session: 704. Immunotherapies: Poster II
Hematology Disease Topics & Pathways:
Biological, Diseases, Therapies, CAR-Ts, B-Cell Lymphoma, Clinically relevant, Lymphoid Malignancies
Sunday, December 8, 2019, 6:00 PM-8:00 PM
Hall B, Level 2 (Orange County Convention Center)

Mazyar Shadman, MD1, Ajay K. Gopal, MD2, Stephen D. Smith, MD3, Ryan C. Lynch, MD3, Chaitra S. Ujjani, MD3, Cameron J. Turtle, MBBS, PhD4, Adam Greenbaum, MD, PhD5, Mary Redman5*, Cecilia Yeung, MD4*, Martina Sersch, MD PhD6*, Edus H. Warren, MD, PhD4, David G. Maloney, MD PhD5 and Brian G. Till, MD4

1Uw/Fred Hutchinson Cancer Research Center, Seattle, WA
2Seattle Cancer Care Alliance, Seattle, WA
3University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA
4Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA
5Fred Hutchinson Cancer Research Center, Seattle, WA
6Mustang Bio, Inc., New York, NY

Background: Chimeric antigen receptor T-cells (CAR-T) targeting CD19 have shown clinical efficacy in high-risk B-cell lymphomas, which has led to approval of 2 such therapies (axicabtagene ciloleucel and tisagenlecleucel) for large B-cell lymphoma after 2 lines of treatment. Despite the promising results, complete remission (CR) is achieved in ~ 50% of patients, and with longer follow-up progression-free survival is around 40%. Therefore, finding effective treatments for high-risk B-NHLs remains an unmet need. CD20 is a proven therapeutic target for B-Cell Non-Hodgkin Lymphomas (B-NHL), supported by previously approved naked and radiolabeled anti-CD20 monoclonal antibodies and a number of studies investigating novel bispecific antibodies targeting this antigen. CD20-targeted CAR-T is another potential adoptive immunotherapy option that could be utilized in combination or sequentially before or after CD19 CAR-T, depending on efficacy. Here, we present our ongoing phase I/II clinical trial investigating safety and efficacy of CD20 CAR-T for high-risk B-NHLs (NCT03277729).

Methods: MB-106 is a fully human third-generation CD20 targeted CAR-T with both 4-1BB and CD28 costimulatory domains. In the phase I portion of the study we use a continual reassessment method dose escalation design to find the maximally tolerated dose. Lymphodepletion (LD) chemotherapy consists of fludarabine and cyclophosphamide. Patients (pts) will undergo a mandatory biopsy before LD to confirm the diagnosis and CD20 expression. A repeat research biopsy will be done between 10-16 days after CAR-T infusion (Figure 1). Except for the first patient of each dose cohort, treatment is given in the outpatient setting (Fred Hutch/Seattle Cancer Care Alliance) and pts will only be admitted to the University of Washington Medical Center if clinically indicated after CAR-T infusion. Response to treatment will be assessed on day 28 using Lugano criteria. Patients with relapsed or refractory CD20 positive B-NHL are eligible, including but not limited to DLBCL, primary mediastinal lymphoma, follicular lymphoma or other indolent histologies, and mantle cell lymphoma. Prior treatment with CD19 CAR-T is permitted as long as there is evidence of B-cell recovery in peripheral blood (≥ 20 B cells/µl) as a functional test to rule out persistent CD19 CAR-Ts. Patients need to meet standard organ function criteria and have adequate blood counts (ANC >750, Hb >8.5, Plts >50,000). Patients with significant neurologic conditions, active CNS lymphoma, or need for systemic immunosuppressive therapy are excluded from the study.

Disclosures: Shadman: Mustang Bio: Research Funding; Verastem: Consultancy; Genentech: Consultancy, Research Funding; Atara Biotherapeutics: Consultancy; Pharmacyclics: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Celgene: Research Funding; Sound Biologics: Consultancy; TG Therapeutic: Research Funding; Acerta Pharma: Research Funding; Sunesis: Research Funding; Gilead: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; BeiGene: Research Funding; Astra Zeneca: Consultancy. Gopal: Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding. Smith: Pharmacyclics: Research Funding; Genentech: Research Funding; Ignyta (spouse): Research Funding; Portola Pharmaceuticals: Research Funding; Bristol-Myers Squibb (spouse): Research Funding; Ayala (spouse): Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma BV: Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; Incyte Corporation: Research Funding; Seattle Genetics: Research Funding; Denovo Biopharma: Research Funding. Lynch: Juno Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A: Research Funding; Takeda Pharmaceuticals: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Incyte Corporation: Research Funding; T.G. Therapeutics: Research Funding. Ujjani: Pharmacyclics: Honoraria; PCYC: Research Funding; Gilead: Consultancy; Astrazeneca: Consultancy; Atara: Consultancy; Genentech: Honoraria; AbbVie: Honoraria, Research Funding. Turtle: T-CURX: Membership on an entity's Board of Directors or advisory committees; Humanigen: Other: Ad hoc advisory board member; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Kite/Gilead: Other: Ad hoc advisory board member; Novartis: Other: Ad hoc advisory board member. Yeung: Pfizer: Research Funding; OBI Pharmaceutical: Research Funding; Merck: Consultancy; DiaCarta: Consultancy. Sersch: Mustang Bio: Employment. Maloney: Juno Therapeutics: Honoraria, Patents & Royalties: patients pending , Research Funding; Celgene,Kite Pharma: Honoraria, Research Funding; BioLine RX, Gilead,Genentech,Novartis: Honoraria; A2 Biotherapeutics: Honoraria, Other: Stock options . Till: Mustang Bio: Patents & Royalties, Research Funding.

*signifies non-member of ASH