Moleculin Biotech, Inc. (Nasdaq: MBRX) is advancing its lead drug candidate, Annamycin, towards a pivotal Phase 3 clinical trial for relapsed or refractory acute myeloid leukemia (R/R AML). The "MIRACLE" trial is designed as an adaptive study and is slated to begin dosing patients in the first quarter of 2025. This trial aims to evaluate Annamycin in combination with cytarabine for potential accelerated approval.
Advancing Annamycin in AML Treatment
The MIRACLE trial (MB-108) is a global study designed to assess the efficacy and safety of Annamycin in combination with cytarabine (AnnAraC) in patients with R/R AML. The adaptive design will initially randomize approximately 75 to 90 subjects to receive high-dose cytarabine (HiDAC) combined with either placebo, 190 mg/m2 of Annamycin, or 230 mg/m2 of Annamycin. An interim analysis will then be conducted to select the optimal dose of Annamycin for the second part of the trial, which will involve randomizing approximately 240 additional subjects to receive either HiDAC plus placebo or HiDAC plus the optimal dose of Annamycin. The selection of the optimum dose will be based not only on the overall balance of safety, tolerability, pharmacokinetics and efficacy, consistent with the FDA's new Project Optimus initiative.
Walter Klemp, Chairman and CEO of Moleculin, stated, "We are thrilled to have emerged as a late stage company... We believe with our recent clinical and regulatory 'wins,' we have foundationally set the stage for a transformational year ahead and the opportunity to drive significant value for all stakeholders."
Promising Data from Phase 1B/2 Trial
Data from the MB-106 Phase 1B/2 clinical trial of Annamycin plus cytarabine in AML continues to show encouraging results, with the median durability of complete response composite (CRc) now exceeding eight months. This extended durability suggests a potential for Annamycin to provide a meaningful benefit in a patient population with limited treatment options.
Annamycin's Potential Impact on AML Treatment Landscape
A recent virtual Key Opinion Leader (KOL) event highlighted Annamycin's potential to significantly change the AML treatment landscape. Experts discussed the use of anthracyclines and how Annamycin, with its unique mechanism of action, could address unmet needs in R/R AML.
Development for Soft Tissue Sarcoma Lung Metastases
Moleculin Biotech is also evaluating Annamycin as a monotherapy for the treatment of soft tissue sarcoma (STS) lung metastases. Enrollment is complete in the Phase 2 portion of the U.S. Phase 1B/2 clinical trial (MB-107), and the clinical study report is expected to be completed in early 2025. Subjects who had stable disease at the time of study discontinuation were followed for progression free response and overall survival.
Financial Update
For the third quarter of 2024, Moleculin Biotech reported a research and development expense of $4.9 million, compared to $3.3 million for the same period in 2023. As of September 30, 2024, the company had cash and cash equivalents of $9.4 million, which is expected to fund planned operations into the first quarter of 2025.
Upcoming Milestones
Key milestones expected for the Annamycin AML development program include:
- 4Q 2024 – Contracting with MIRACLE trial sites and IRB approval
- 1Q 2025 – First subject treated in MIRACLE trial
- 4Q 2025 – Recruitment and overall efficacy rate update (n=45)
- 2H 2026 – Interim efficacy and safety data (n=90) unblinded and Optimum Dose set for MIRACLE trial
- 2028 2H – Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE
