MB-105 in Patients With CD5 Positive T-cell Lymphoma

The first stage of the Simon two-stage design will enroll approximately 15 evaluable patients. Once the first 6 patients are enrolled, have received one dose of MB-105 at the recommended phase 2 dose (RP2D), and completed at least up to Day 30 of the study, the Independent Data Monitoring Committee (IDMC) will perform a safety analysis. The IDMC will use this analysis to confirm that the RP2D selected for this Phase 2 study is the appropriate dose of MB-105 for further clinical evaluation. The IDMC will either recommend continuing the remainder of the study at the fixed dose of 50 million (5 x 107) Chimeric antigen receptor (CAR) positive cells or recommend other actions, which could include repeating the safety run-in with either a lower or higher dose. The IDMC will not recommend a MB-105 dose greater than those found safe in the phase 1 study. During the safety analysis period after the 6th patient is treated and awaiting data analysis, patients will continue to be screened but not dosed until the IDMC recommendation is made.

If the IDMC confirms the suggested RP2D is the appropriate dose for further clinical evaluation, the study will enroll an additional 9 patients to complete 15 total patients for Stage 1 to obtain a preliminary estimate of response rate per Lugano criteria for peripheral T-cell lymphoma (PTCL) and 2022 Global criteria for cutaneous cases (CTCL). At the end of Stage 1, defined as when the last patient enrolled completes study visits up to Day 56, including efficacy assessment, the IDMC will convene to review all available Stage 1 data and recommend continuation to Stage 2 or closure of enrollment.

Stage 2 will enroll approximately 31 patients, for a total of 46 patients in the study. During Stage 2 the IDMC will convene at least once every 6 months to review safety and efficacy on an ongoing basis. No formal interim analysis is planned after the end of Stage 1, but since this is an open-label study, interim data extracts may be performed to support abstract submissions, presentations, or regulatory discussions. The study will end once the last patient completes at least 12 months of follow-up and end of study (EOS) visit. After EOS, all patients will be asked to participate in a separate long term follow-up (LTFU) study.