Surface Oncology Announces First Patient Dosed in Phase 1 Clinical Trial of SRF231

CAMBRIDGE, Mass., March 20, 2018 - Surface Oncology, an immuno-oncology company developing next-generation antibody therapies that target the tumor microenvironment, today announced that the first patient was treated in its Phase I trial of SRF231, the company’s lead product candidate. SRF231 is a fully human antibody that inhibits the activity of CD47, a protein overexpressed on many types of cancer cells which prevents them from being engulfed and eliminated by macrophages.

“The initiation of this clinical trial is a milestone for Surface and demonstrates the outstanding progress we’ve made in advancing our innovative oncology pipeline,” said Rob Ross, M.D., chief medical officer of Surface Oncology. “SRF231 is the first of what we expect will be multiple novel agents that we bring into clinical development to help patients suffering from cancer.”

Initially, this multi-center, open-label Phase I trial will evaluate the safety and tolerability of SRF231 in multiple ascending doses in patients with advanced solid tumors and hematologic malignancies with the objective of establishing a recommended dose for further study. Following the dose escalation component of the trial, Surface intends to evaluate the safety and efficacy of SRF231 in cohorts of patients with specific types of cancer.

“Targeting the tumor microenvironment has tremendous therapeutic potential,” said Amita Patnaik, M.D., F.R.C.P.C., Associate Director of Clinical Research at South Texas Accelerated Research Therapeutics and an investigator on the trial. “Our team is eager to evaluate the role of macrophage activation through SRF231 to expand the opportunities for patients with cancer to benefit from immunotherapy.”


SRF231 is a fully human monoclonal antibody therapeutic targeting CD47, a protein overexpressed on many cancer cells which prevents them from being engulfed and eliminated by macrophage mediated phagocytosis. SRF231 preclinical results presented at the 2016 Society for Immunotherapy of Cancer (SITC) and the American Society of Hematology (ASH) meetings demonstrated that SRF231 has potent anti-tumor activity preclinically in several different tumor models and in combination with existing cancer modalities. Importantly, preclinical studies also showed that SRF231 does not induce hemagglutination, an important potential safety advantage.

Surface Oncology is an immuno-oncology company developing next-generation antibody therapies focused on the tumor microenvironment with lead programs targeting CD47 and CD73. Surface’s novel cancer immunotherapies are designed to achieve a clinically meaningful and sustained anti-tumor response and may be used alone or in combination with other therapies. The company has a pipeline of seven novel immunotherapies and a strategic collaboration with Novartis focused on up to three next-generation cancer immunotherapies. Headquartered in Cambridge, Mass., Surface was founded by Atlas Venture. For more information, please visit



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