PT217 is a first-in-class bispecific antibody (bsAb) against human DLL3 (huDLL3) and human CD47 (huCD47) and is Phanes’ third program in the clinic

SAN DIEGO, CA, USA I September 7, 2023 I Phanes Therapeutics, Inc. (Phanes), a clinical stage biotech company focused on innovative drug discovery and development in oncology, announced today that the first patient has been dosed in the Phase 1 clinical study (NCT05652686) of PT217, a first-in-class native IgG-like bispecific antibody (bsAb) targeting DLL3 and CD47 for the treatment of small cell lung cancer and other neuroendocrine tumors. PT217 is a common light chain bispecific antibody discovered through Phanes’ research engine and was granted orphan drug designation (ODD) for the treatment of small cell lung cancer by the FDA last year.

PT217 is expected to directly kill tumor cells via both the ADCP activity of macrophages and ADCC activity of NK cells, and by targeting both DLL3 and CD47 expressed on the surface of tumor cells, it can broaden the tumor killing spectrum. Additionally, PT217 is expected to induce the presentation of tumor neoantigens by channeling tumor cells into phagocytotic antigen presenting cells (APCs) and stimulate adaptive immune system by indirectly activating T cell killing of DLL3 expressing tumor cells through recognition of tumor neoantigens. The anti-CD47 arm of PT217 is differentiated and has demonstrated minimum binding to human red blood cells while maintaining strong binding activity to CD47 on tumor cells. “Small cell lung cancer is one of the most devastating and aggressive solid tumor cancers with patients lacking effective therapies to treat their disease. With the advancement of PT217, we offer a potential new option for these patients. PT217 is a product of Phanes’ ingenious innovation in creative design of both novel therapeutic approaches and practical technologies,” said Dr. Ming Wang, Founder and CEO of Phanes.

The multi-center Phase I clinical trial of PT217 is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of PT217 in patients with unresectable or small cell lung cancer (SCLC), large cell neuroendocrine cancer (LCNEC), neuroendocrine prostate cancer (NEPC) and gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) that have progressed after all available standard therapy or for which standard therapy has proven to be ineffective, intolerable, or is considered inappropriate.

For more information on the study please visit (NCT05652686).


Phanes Therapeutics, Inc. is a clinical stage biotech company focused on innovative drug discovery and development in oncology. Currently, it has three assets at clinical stage, including its best-in-class monoclonal antibody (mAb) program, PT199, and two first-in-class bispecific antibody programs, PT886 and PT217.

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SOURCE: Phanes Therapeutics