Moleculin Biotech, Inc. announced the completion of enrollment in the Phase 2 portion of the Company's U.S. Phase 1B/2 clinical trial evaluating Annamycin for the treatment of soft tissue sarcoma lung metastases (MB107). Subjects who had stable disease at time of study discontinuation will continue to be followed for progression free response and overall survival. The Company plans to present a more in-depth review of the topline data on progression free survival, progression free response, overall survival, and other data on this study prior to this year-end.

Additionally, the Company expects to report this and further data, as previously announced, in the Company's poster presentation and in related meetings at the 2023 CTOS (Connective Tissue Oncology Society) Annual Meeting, which is being held November 1-4, 2023 in Dublin, Ireland. Annamycin currently has Fast Track Status and Orphan Drug Designation from the U.S. Food and Drug Administration for the treatment of soft tissue sarcoma, in addition to Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia. For more information about the U.S. Phase 1B/2 clinical trial evaluating Annamycin for the treatment of soft tissue sarcoma lung metastases (MB107) visit clinicaltrials.gov and reference identified NCT04887298.

In Phase 2, Annamycin was administered as an intravenous (IV) infusion over 2 hours on Day 1, followed by 20 days off (1 cycle = 21 days). Subjects visit the study site every 21 days (±3 days) at which time safety monitoring ? including for adverse events (AEs), as well as a physical examination, laboratory evaluations (clinical chemistry, complete blood count), vital signs, weight measurements, Eastern Cooperative Oncology Group (ECOG) performance status, and electrocardiograms (ECGs) ?

is performed, followed by an IV infusion of study drug. Cardiac function is followed by echocardiogram (ECHO) scans at screening, at the end of the first two cycles and then following every other cycle thereafter, at the End of Treatment visit, and if feasible, during follow up at 6 months (±1 month) and 1 year (±1 month) after study drug discontinuation. As long as the Investigator considers that the benefits of treatment with Annamycin continue to outweigh the risks, treatment will continue every 21 days until tumor progression is observed or unacceptable toxicity occurs.

Tumor response is monitored every 6 weeks (±1 week) from Cycle 1 Day 1 during treatment, at the End of Treatment visit, and then every 3 months (±1 month) until disease progression using RECIST 1.1 criteria. Those subjects who leave the study after a maximum response is achieved and who do not start another therapy will be followed every 3 months (±1 month) for progression-free survival (PFS). If a subject receives further therapy after discontinuing from the study, they will be followed only for overall survival (OS) and if feasible, follow-up ECHO scans at 6 months (±1 month) and 1 year (±1 month) will be conducted after study drug discontinuation.

Annamycin is the Company's next-generation anthracycline that has been shown in animal models to accumulate in the lungs at up to 30-fold the level of doxorubicin. Importantly, Annamycin has also demonstrated a lack of cardiotoxicity in multiple early-stage human clinical trials, including ongoing trials for the treatment of acute myeloid leukemia (AML) and STS lung metastases. For that reason, although additional data will be necessary, the Company believes Annamycin may not face the same usage limitations imposed on doxorubicin, one of the most common currently approved anthracyclines.

Annamycin is currently in development for the treatment of AML and STS lung metastases and the Company believes the drug may have the potential to treat additional indications.