FDA Grants Orphan Drug Designation to Annamycin in Soft Tissue Sarcomas

The FDA has granted an Orphan Drug Designation to annamycin for the treatment of patients with soft tissue sarcomas.

The FDA has granted an Orphan Drug Designation (ODD) to annamycin for the treatment of patients with soft tissue sarcomas, Moleculin Biotech, Inc, developer of the agent, announced in a press release.1

“This is now the second ODD for annamycin, as annamycin previously received ODD for the treatment of relapsed or refractory acute myeloid leukemia," commented Walter Klemp, chairman and chief executive officer of Moleculin.

ODD for the anthracycline antibiotic comes on the heels of a request for Investigational New Drug status based on phase 1b/2 data of patients with soft tissue sarcoma whose disease metastasized to the lungs after first-line therapy for their disease.

Results presented during the 2020 American Association of Cancer Research

(AACR) Annual Meeting showed that treatment with annamycin led to high uptake and retention in the lungs of the subjects, resulting in consistently high in vivo activity in a good proportion of the lung tumors. The antitumor activity observed included inhibition of tumor progression to complete tumor eradication in bioluminescent imaging in models of lung-localized cancers. Delay in tumor growth or tumor regression led to a significant improvement in survival for all the models that were tested in the study.2

The median survival was 87.5 days on annamycin with a survival ration of 4.17 versus 21 days with saline with a survival ratio of 1. The P value for the difference between the treatment arms was < .0001.

In addition to data from AACR, independent laboratory data for annamycin was shown to be capable of achieving 6- to 34-fold higher levels of accumulation in the lungs than that of doxorubicin, which is the current standard of care chemotherapy for the treatment of front0line soft tissue sarcoma. Although the safety of annamycin has not been evaluated in patients, clinical data show no cardiotoxicity associated with the agent. In addition, the drug avoids multidrug resistance mechanisms.1


1. Moleculin announces annamycin receives FDA Orphan Drug Designation for soft tissue sarcomas. News release. Moleculin Biotech, Inc. December 29, 2020. Accessed January 4, 2021. https://prn.to/3pMP4pJ

2. Zielinski R, Grela K, Zuniga RC, et al. Targeting sanctuary sites of cancer: Novel approaches to treatment of lung localized tumors. Poster presented at: 2020 AACR Annual Meeting; June 22-24, 2020.