Moleculin Biotech (MBRX) Study Update summary

Background on soft tissue sarcoma and current treatment landscape

• Soft tissue sarcoma (STS) is a rare cancer, with about 13,000 new U.S. cases annually, often metastasizing to the lungs, leading to poor prognosis and limited treatment options.

• First-line therapy is typically Doxorubicin-based, but response rates are low and toxicities, especially cardiotoxicity, are significant.

• Second-line therapies are histology-driven with limited efficacy, and immunotherapies have not shown compelling results.

• Median overall survival for metastatic STS is 12-18 months, with progression-free survival in first line usually 2-4 months.

Annamycin’s unique profile and rationale for MB-107 trial

• Annamycin was designed to eliminate anthracycline cardiotoxicity and is formulated in multilamellar liposomes.

• Demonstrated no drug-related cardiotoxicity even at doses up to five times the FDA anthracycline limit.

• Animal studies show Annamycin concentrates in the lungs at 30 times the rate of Doxorubicin, supporting its use for lung metastases.

• Lacks cross-resistance with Doxorubicin, making it suitable for patients previously treated with anthracyclines.

• Annamycin is a next-generation anthracycline designed to avoid multidrug resistance and cardiotoxicity, targeting hard-to-treat cancers.

MB-107 phase 1B/2 trial design and patient population

• Phase 1B established the recommended phase 2 dose at 330 mg/m²; phase 2 enrolled 17 more subjects for a total of 36 (32 evaluable).

• Patients had unresectable lung metastases, progressive disease after prior therapy, and a median of six prior treatments.

• Median overall survival for all subjects was 13.5 months, exceeding historical second-line monotherapy outcomes.

• Final data from the U.S. Phase 1B/2 trial of Annamycin as monotherapy for STS lung metastases (MB-107) was discussed in a KOL webcast.