FDA Unhalts Phase 1 Trial of MT-0169 in R/R Myeloma and NHL

The FDA has lifted a partial clinical hold previously placed on the phase 1 trial of MT-0169 in patients with relapsed or refractory multiple myeloma or non-Hodgkin lymphoma.¹

The trial halt was the result of disclosed asymptomatic and fully reversible cardiac adverse events in 2 patients who were treated with MT-016 at the 50 mcg/kg dose level. The events led to a major dose reduction to 5 mcg/kg, in the trial. Recent safety data from the study was provided to the FDA, leading to the lift of the partial clinical hold.

“We are pleased that the FDA has removed the partial clinical hold,” said Eric Poma, PhD, chief executive and chief scientific officer, Molecular Templates, Inc, in a press release.

As the phase 1, open-label, dose escalation and expansion study resumes, approximately 44 patients with RRMM or R/R NHL will be enrolled. In the dose-escalation phase, patients will receive MT-0169 via intravenous (IV) infusion every 7 days on days 1, 8, 15, and 22, in a 28-day cycle. Treatment will continue until progressive disease develops, patients experience unacceptable toxicity, or they withdraw from the study.2 In the dose-expansion phase, patients with RRMM will receive weekly dosing of MT-0169. Treatment will occur 7 days on days, 1, 8, 15, and 22 of a 28-day cycles. MT-0169 will be given at the recommended phase 2 dose (RP2D). Patients with R/R NHL included in the dose-escalation phase will be administered biweekly treatment on days 1 and 15, in a 28-day cycle.²

During part 1, the study will assess safety/tolerability as its primary end point, which will be determined by the maximum-tolerated dose of MT-0169, number of patients with treatment-emergent AEs (TEAEs), dose-limiting toxicities, number of patients with grade 3 or higher TEAEs, the number of patients with serious AEs, number of patients who discontinue treatment, and the number requiring treatment-related dose modifications. During part 2, the coprimary end points to be assessed include overall response rate, and ORR in the R/R NHL population.

The secondary end point of the study include pharmacokinetics, clinical benefit rate, disease control rate, progression-free survival, duration of response, the number of patient with anti-drug antibodies following treatment administration, number of patients with DLTs, number of patients with TEAEs, overall survival, time to response, percentage of patient with a complete or very good partial response to treatment, and measurement of R/R NHL tumor CD38 expression level.

Patients are eligible for the study if they have a confirmed diagnosis of either RRMM or R/R NHL, measurable disease, and an ECOG performance status of 0 or 1. In addition, patients are required to have a normal QT interval and adequate laboratory values at baseline.

“MT-0169 represents a novel approach to myeloma that is demonstrating good safety with early signs of potential clinical benefit, particularly in the extramedullary setting, where we have seen a stringent Complete Response in a patient who remains on study for 10 months,” said Poma, in the press release.¹

_REFERENCES:

_{1. Molecular Templates announces the FDA removal of partial clinical hold in the phase 1 clinical trial for MT-0169 and focuses on extramedullary myeloma. News release. June 1, 2023. Accessed June 2, 2023. https://tinyurl.com/bdhv3z6f}

_{2. A study of MT-0169 in participants with relapsed or refractory multiple myeloma or non-hodgkin lymphoma. ClincalTrials.gov. Updated September 8, 2022. Accessed April 12, 2023. https://clinicaltrials.gov/ct2/show/NCT04017130}