Multiple Myeloma Treatment, SRF231, Receives Orphan Drug Designation by FDA

The US Food and Drug Administration (FDA) has granted an orphan designation to Surface Oncology’s SRF231 for the treatment of multiple myeloma, a rare blood cancer characterized by a 5-year life expectancy post stage 1 diagnosis.

SRF231 is a fully human antibody that inhibits the activity of CD47, a protein overexpressed on many types of cancer cells that prevents them from being engulfed and eliminated by macrophages.

“While the potential applications for SRF231 in oncology are quite broad, we are particularly excited about the opportunity to provide benefit to patients with multiple myeloma. We have already demonstrated the ability of our antibody to increase phagocytosis of myeloma cells and to shrink tumors in preclinical models,” said Rob Ross, MD, chief medical officer of Surface Oncology, in a recent statement. “Receiving orphan designation for SRF231 represents an important milestone as we continue to progress the program in the clinic in multiple myeloma and other cancer types.”

Strong preclinical results regarding SRF231 were presented at the 2016 Society for Immunotherapy of Cancer (SITC) and the American Society of Hematology (ASH) meetings. Specifically, the data showed SRF231 has potent in vivo anti-tumor activity preclinically in both as monotherapy and in combination settings. Preclinical findings also indicated that SRF231 does not induce hemagglutination which is an important safety advantage.

Currently, a 2-part open-label, first-in-human, monotherapy phase 1 trial assessing the safety, efficacy, and tolerability of SRF231 is underway. Part A will evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of SRF231as a monotherapy Part A will evaluate the safety and tolerability of SRF231 as a monotherapy via dose escalation in patients with advanced solid tumors and lymphoma/chronic lymphocytic leukemia, and Part B will evaluate 1 or 2 doses or dosing frequencies of SRF231 in select advanced solid and hematologic malignancies depending upon the results from Part A.

Current primary outcome measures for the trial include the dose-limiting toxicity (DLT), non-tolerated Dose (NTD), maximum tolerated Dose (MTD) in Part A and a safety analysis that summarizes adverse events (AEs) based on treatment-emergent AEs (TEAEs) in both Part A and Part B. All primary outcome measures will be within the timeframe of 24 months with 21-day drug treatment cycles.

The anticipated primary completion date for the trial is September 18, 2020.