New, Multicenter Trial of MB-106 Doses First Patient

A phase 1/2 clinical trial (NCT05360238) has dosed its first patient with MB-106 (Mustang Bio), a chimeric antigen receptor (CAR) T-cell therapy for the treatment of relapsed or refractory B-cell non-Hodgkin lymphomas (B-NHL) and chronic lymphocytic leukemia (CLL).

The patient did not experience cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). The trial is a multicenter, open-label trial that builds on the ongoing trial at Fred Hutchinson Cancer Center under the same investigational new drug application (IND). It is evaluating the safety and efficacy of MB-106, a first-in-class CD20-targeted, autologous CAR T cell therapy.

“The first clinical trial under Mustang’s IND is an important milestone in the ongoing development and evaluation of MB-106. Data presented at several prestigious medical meetings earlier this year from the initial, ongoing Phase 1/2 clinical trial at Fred Hutch show that MB-106 continues to demonstrate high efficacy and a favorable safety profile across patients with a wide range of hematologic malignancies. We look forward to providing updates on our multicenter MB-106 clinical trial as it progresses and anticipate reporting efficacy data in the fourth quarter of this year,” Manuel Litchman, MD, president and chief executive officer, Mustang, said, in a statement.

Recent interim data, as of September 9, 2022, from 28 patients treated in the ongoing, investigator-sponsored study, have continued to support MB-106's benefit. No patients experienced CRS or ICANS greater than grade 3. Overall response rate is 96% and complete response (CR) rate is 75% in patients with follicular lymphoma, CLL, diffuse large B-cell lymphoma, and Waldenstrom macroglobulinemia.

WATCH NOW: Mazyar Shadman, MD, MPH, on MB-106's Potential in Follicular Lymphoma

Twelve patients had a CR for over 12 months with 10 CRs still ongoing. The longest CR is 33 months, and 4 patients had a CR for over 2 years. Six patients with a partial response (PR) improved to ongoing CRs. Three patients had been previously treated with CD19 CAR T-cell therapy and all responded. Investigators also found that CAR-T persistence resulted in deepening responses after the initial 28-day assessment.

“We are excited to broaden the evaluation of MB-106 with this multicenter clinical trial under Mustang’s IND. To date, the data from the initial, ongoing clinical trial at Fred Hutch continue to demonstrate a high rate of complete and durable responses,” Mazyar Shadman, MD, MPH, study chair, associate professor and physician, Fred Hutch and University of Washington, added to the statement. “In addition, MB-106 has shown potential to treat patients in an outpatient setting and provide another immunotherapy option for patients treated previously with CD19-directed CAR T cell therapy.”

The trial is aiming to enroll 287 patients with CLL and B-NHLs, including mantle cell lymphoma. Patients must have evidence of CD20 expression. Phase 1 of the trial will assess escalating dose levels of MB-106 in a 3+3 design in 3 arms. Each arm will have up to 18 patients, with 6 at the maximum tolerated dose. The Safety Review Committee will assess 28-day data and the recommended phase 2 dose will be established. In the phase 2 portion, a total of 71 patients will participate with up to 20 patients in each arm. Up to an additional 51 patients may be added to each arm after an interim analysis.

REFERENCE

Mustang Bio announces first patient treated in its multicenter phase 1/2 clinical trial of MB-106, a first-in-class CD20-targeted, autologous CAR T cell therapy to treat B-cell non-hodgkin lymphoma and chronic lymphocytic leukemia. News release. Mustang Bio. October 6, 2022. https://www.globenewswire.com/news-release/2022/10/06/2529538/0/en/Mustang-Bio-Announces-First-Patient-Treated-in-Its-Multicenter-Phase-1-2-Clinical-Trial-of-MB-106-a-First-in-Class-CD20-targeted-Autologous-CAR-T-Cell-Therapy-to-Treat-B-cell-Non-H.html