Avanish Vellanki, MBA and Robert Doebele, MD, Ph.D., Chief Executive Officer, and Co-founder, and President, Chief Scientific Officer & Co-founder of Rain Therapeutics discusses Rain Therapeutics Initiates Phase 3 MANTRA Clinical Trial of Milademetan for De-differentiated Liposarcoma and Provides Patient Update from Prior Clinical Program.
Link to Study:
https://clinicaltrials.gov/ct2/show/NCT04979442
Rain Therapeutics Inc., a clinical-stage company focused on precision oncology therapeutics, announced today that the first patient in the multicenter, open-label, Phase 3 registrational study (MANTRA) evaluating milademetan (RAIN-32), an oral mouse double minute 2 (MDM2) inhibitor, for the treatment of DD LPS has been randomized.
The MANTRA trial is a randomized, multicenter, open-label, Phase 3 registrational study that will compare RAIN-32 to trabectedin, a current standard of care, in patients with unresectable or metastatic DD LPS with or without a well-differentiated (WD) LPS component who have progressed on one or more prior systemic therapies, including at least one anthracycline-based therapy. A total of 160 individuals will be randomly assigned to either milademetan or trabectedin in a 1:1 ratio. The trial’s main goal is to evaluate progression-free survival (PFS) between the milademetan treatment arm and the trabectedin control arm using a blinded independent review. Overall survival, PFS by investigator judgment, objective response rate, duration of response, disease control rate, safety, and patient-reported outcomes are all secondary goals.
Patients in the previously completed Phase 1 dose-escalation and expansion study are still receiving RAIN-32 monotherapy, according to the company. Three WD/DD LPS patients had been on milademetan monotherapy for more than 51 months as of July 1, 2021. Two of these patients are still on therapy, with durations of 51 and 57 months respectively, with no signs of disease progression, and a third patient was on therapy for more than 59 months until being stopped in the second quarter of 2021. This points to the possibility of milademetan having a favorable long-term tolerability and safety profile.
About Liposarcoma (Well-Differentiated/Dedifferentiated)
Liposarcoma is rare cancer that arises from fat cells in the body’s soft tissues. It is a cancerous tumor that has the potential to spread to other sections of the body. LPS that has been well-differentiated is less aggressive and appears as a big, painless lump in deeper tissues. Dedifferentiated (DD) LPS, which develops from WD LPS, is more aggressive and is typically detected in the tissue below the abdominal area or in the extremities. The most common subtypes of LPS are WD/DD LPS, which share common genomic abnormalities, most notably MDM2 gene amplification. In the United States, the incidence of LPS is believed to be around 3,000 people per year, with few viable treatment options.