NCT04915846

Tamoxifen Therapy for Myotubular Myopathy

TAM4MTM: a Phase 1/2 Randomized, Placebo-Controlled, Double-Blinded, Single Crossover Study to Determine the Safety and Efficacy of Tamoxifen Therapy for Myotubular Myopathy (XLMTM)

• Status: Terminated
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 6 (actual)
• Sponsor: James Dowling · Academic / Other
• Sex: Male
• Age: 6 Months
• Healthy volunteers: Not accepted

Summary

This is a phase 1 / 2, randomized, double-blinded, single cross-over study, with a washout period between treatment regimens, to test the efficacy and safety of tamoxifen therapy to improve motor and respiratory function in males with XLMTM.

Detailed description

Pre-clinical studies in Mtm1 knockout mice (a model of XLMTM) demonstrated prolonged survival, increased motor function (including muscle strength), and improved muscle histopathology with tamoxifen treatment. Based on these data, and the known safety profile of the drug in humans, we hypothesize that tamoxifen treatment will be safe and will improve motor and respiratory function in XLMTM patients. This is a randomized, double-blinded, single crossover clinical trial to test this hypothesis and determine the safety and efficacy of tamoxifen in improving motor and respiratory function in MTM patients. Each subject will serve as his own control during the placebo phase of the study. As treatments for XLMTM are current not available, this study addresses a critical unmet need by testing a therapy that, if effective, may serve as a primary treatment, or in the future as an adjunct to other therapies in development.

Conditions

• X Linked Myotubular Myopathy

Interventions

Type	Name	Description
DRUG	ApoTamox 10mg	All participants will receive tamoxifen (ApoTamox) for approximately 6 months (6 months + 1 week). Participants and study staff will be blinded as to whether the participants are starting with the placebo or the drug. Depending on randomization, drug or placebo will be dispensed at the end of the t=0 study visit (Phase 1). Dosing will commence the day after the t=0 study visit. At the end of Phase 1, participants will enter a 'washout' period, when they will cease treatment. After approximately 3 months of washout, participants will cross-over to the other treatment regimen and receive the other interventional product (IP) for the final 6 months of their study participation (Phase 2).
DRUG	Placebo	placebo comparator

Timeline

• Start date: 2020-12-18
• Primary completion: 2024-05-09
• Completion: 2024-05-09
• First posted: 2021-06-07
• Last updated: 2024-09-19

Locations

4 sites across 3 countries: United States, Canada, United Kingdom

Regulatory

• FDA-regulated drug study