Benzinga | Jun 11, 2021 06:31AM EDT

Mustang Bio Offers Interim Phase 1/2 Data For MB-106 CD20-Targeted CAR T In Patients With Relapsed, Refractory B-Cell Non-Hodgkin Lymphomas, Chronic Lymphocytic Leukemia: 93% overall response rate and 67% complete response rate

Data presented at the European Hematology Association 2021 Virtual Congress show favorable safety profile and compelling clinical activity

93% overall response rate and 67% complete response rate in patients treated with modified cell manufacturing process

Key opinion leader webinar on Tuesday, June 15, 2021, at 1 p.m. ET

WORCESTER, Mass., June 11, 2021 (GLOBE NEWSWIRE) -- Mustang Bio, Inc. ("Mustang") (NASDAQ:MBIO), a clinical-stage biopharmaceutical company focused on translating today's medical breakthroughs in cell and gene therapies into potential cures for hematologic cancers, solid tumors and rare genetic diseases, today announced updated interim data from the ongoing Phase 1/2 clinical trial investigating the safety and efficacy of MB-106 CD20-targeted, autologous CAR T cell therapy for high-risk B-cell non-Hodgkin lymphomas ("B-NHL") and chronic lymphocytic leukemia ("CLL"). MB-106 is being developed in a collaboration between Mustang and Fred Hutchinson Cancer Research Center("Fred Hutch").

The data presented in an e-poster session at the European Hematology Association 2021 Virtual Congress ("EHA2021") by Mazyar Shadman, M.D., M.P.H., Associate Professor, Clinical Research Division of Fred Hutch, included safety and efficacy data from the cell manufacturing process that was modified to combine the culture of CD4+ and CD8+ cells. In the 15 patients treated, the overall response rate ("ORR") was 93% (14/15) with a complete response ("CR") rate of 67% (10/15). In 11 patients with follicular lymphoma ("FL"), ORR and CR were 91% (10/11) and 82% (9/11), respectively. As of the time of the e-poster submission to EHA2021, all patients who achieved CR remained in remission. One patient with FL had an initial partial response with a later disease progression, had a spontaneous CR and remains in remission. The patient with CLL also had a CR and undetectable measurable residual disease in peripheral blood and bone marrow by flow cytometry (10-4) (uMRD4) on day 28. CAR T persistence was seen in all dose levels ("DL") and, while expansion was faster in higher DL, the levels were comparable by day 28.

From a safety profile perspective, cytokine release syndrome ("CRS") occurred in 6 patients (40%): 3 patients with grade 1 and 3 patients with grade 2. Only 1 patient (6.5%) experienced grade 2 immune effector cell-associated neurotoxicity syndrome ("ICANS") and none of the 11 patients with FL experienced ICANS of any grade. No grade 3 or higher CRS or ICANS were seen in any patient.

Dr. Shadman commented, "MB-106 continues to demonstrate a very favorable safety and efficacy profile, as well as sustained complete responses. This compelling clinical activity, including the complete remissions in 67% of the patients in the trial, demonstrates the potential of MB-106 as a viable CD20-targeted CAR T cell therapy. We are pleased that all complete responders continue to remain in remission, and we continue to enroll all eligible CD20+ NHL and CLL patients into this trial."

Manuel Litchman, M.D., President and Chief Executive Officer of Mustang, said, "We are encouraged by the updated MB-106 safety and efficacy data presented by Dr. Shadman today. As reported last month, the FDA has accepted Mustang's IND application to initiate a multicenter Phase 1/2 clinical trial investigating the safety, tolerability and efficacy of MB-106 for relapsed or refractory B-NHL and CLL. We look forward to commencing the trial later this year and further advancing MB-106 for patients with B-NHL and CLL who are in need of new treatment options."

For more information on the clinical trial at Fred Hutch, please visit www.clinicaltrials.gov using the identifier NCT03277729.