Cyteir Therapeutics Advances Clinical Trial of Lead RAD51 Synthetic Lethality Program in Cancer and Expands Senior Leadership Team

  • Phase 1/2 study of first-in-class inhibitor of RAD51-mediated homologous recombination advancing to once-daily dosing
  • Secrist, Gengos and Englert join Cyteir leadership team, enhancing company’s scientific, strategic business development, and drug development expertise

LEXINGTON, Mass., July 7, 2020Cyteir Therapeutics, a leader in the discovery and development of next-generation synthetic lethal therapies for cancer, today announced continued progress in their Phase 1/2 clinical study evaluating the company’s lead compound, CYT-0851. Emerging evidence demonstrating the pharmacokinetic behavior of CYT-0851 in patients to date has enabled the transition from twice daily to once-a-day dosing, which is most ideal for patients.

Additionally, the company announced the appointment of three senior executives, all with extensive pharmaceutical and biotechnology leadership experience.

“We progressed from initial compound discovery to the clinic in just two years, and early findings from our first clinical study of CYT-0851 suggest that we will be able to maintain this exceptional momentum,” said Markus Renschler, M.D., Cyteir president and CEO. “We’re excited to be leading the only clinical program targeting RAD51-mediated homologous recombination.”

CYT-0851 is based on the discovery that some tumor cells become more dependent on a DNA repair pathway that is mediated by RAD51, a protein that is essential for the continued survival of these particular cancer cells. Inhibiting RAD51-mediated homologous recombination in these cancer cells limits their ability to self-repair, leading to overwhelming DNA damage and ultimately, self-destruction – a therapeutic effect known as synthetic lethality. In pre-clinical studies, CYT-0851 demonstrated selective and potent activity in both B-cell malignancies and solid tumors, as well as synergy with PARP inhibitors and chemotherapy. These findings support the broad potential for CYT-0851 to address the high unmet clinical need across various cancers and stages.

Cyteir initiated the Phase 1/2 study of CYT-0851 in October 2019. It is designed to enroll a total of approximately 200 patients with advanced non-Hodgkin lymphoma, chronic lymphocytic leukemia, multiple myeloma, breast cancer, ovarian cancer, head and neck cancer, soft tissue sarcoma, or pancreatic cancer. The Phase 1 study will evaluate the safety and tolerability of CYT-0851 as monotherapy and identify the recommended dose for phase 2 and future studies. This portion of the study is currently enrolling patients at eight leading cancer centers across the United States, and based on findings to date, has changed to once-daily from initial twice-daily dosing. Cyteir anticipates completion of Phase 1 by the end of 2020.

Cyteir is also developing a companion diagnostic assay to identify patients with tumors that overexpress certain cytidine deaminases that may make them more susceptible to RAD51-pathway inhibition, and recently received an investigational device exemption (IDE) from the U.S. Food and Drug Administration to begin evaluating this companion diagnostic in patients.

Leadership Team Expansion

“To further accelerate our clinical program and advance our preclinical pipeline, both of which focus on cancer drugs that target novel synthetic lethal pathways, we have strategically expanded our leadership team,” said Renschler. “Every member of this team has direct experience developing cancer therapies, bringing them to patients who so desperately need them, and building successful biotechnology businesses.”

Cyteir recently appointed Paul Secrist, Ph.D., to the position of chief scientific officer. Dr. Secrist began his pharmaceutical and biotechnology career in 1996 and has since served in scientific leadership roles at companies including OSI Pharmaceuticals, Aton Pharma, Merck & Company and AstraZeneca Pharmaceuticals. In these organizations, Dr. Secrist led multiple preclinical drug discovery, drug development and translational biology programs, focused primarily in oncology. Prior to joining Cyteir, he was the senior vice president of Discovery Research at Lifemine Therapeutics. Dr. Secrist holds a bachelor’s degree in Biology from Wartburg College, and a Ph.D. in Pharmacology from Mayo Graduate School.

The company has also appointed Andrew Gengos as chief business officer and Judson Englert, M.D., Ph.D., as vice president of Clinical Research and Development. Mr. Gengos is a 25-year veteran of the healthcare field, with a history of leadership roles at numerous companies including Dynavax, Amgen and Synlogic. At Amgen, Mr. Gengos served as vice president, Strategy and Corporate Development from 2002 to 2010. Most recently, he served as the chief business officer and chief financial officer at AOBiome Therapeutics. Mr. Gengos holds a Bachelor of Science degree in Chemical Engineering from the Massachusetts Institute of Technology and an MBA from the UCLA Anderson School of Management.

Dr. Englert is a board-certified medical oncologist and physician-scientist with a proven track record in drug development both in the pharmaceutical industry and academia. Dr. Englert served in a leading role in early clinical development of immune-oncology drugs as director of Clinical Development, Oncology, at AstraZeneca/Medimmune. Prior to joining Cyteir, Dr. Englert served as senior director of Translational Sciences at UPMC Enterprises. He holds a Ph.D. in Cellular and Molecular Pathology and an M.D. from the University of Pittsburgh School of Medicine. Dr. Englert trained in Internal Medicine at the Brigham & Women’s Hospital at Harvard University and completed his medical oncology training at Johns Hopkins University.

About CYT-0851

CYT-0851 is an experimental, oral, selective inhibitor of RAD51-mediated homologous recombination, a DNA repair pathway. Cancer cells that overexpress certain DNA-damaging cytidine deaminases rely on homologous recombination and RAD51 to repair DNA damage. In preclinical models, inhibition of this pathway with CYT-0851 induced cell death in cytidine deaminase-overexpressing cell lines and reduced proliferation.

About Cyteir Therapeutics

Cyteir, a private company based in Lexington, Mass., is an innovator in targeting DNA damage response, developing the next generation of synthetic lethal therapies designed to treat cancer. Cyteir exploits the synthetic lethality of gain-of-function DNA-damaging genes and DNA repair inhibition, resulting in selective death among cancer cells with high levels of DNA damage. The company is backed by leading healthcare investors, including Novo Holdings, Venrock, DROIA, Osage University Partners (OUP) and Lightstone Ventures, as well as Celgene Corporation. For more information, visit

© 2020 Cyteir Therapeutics, Inc. All rights reserved. Cyteir Therapeutics, Cyteir, and associated logos are trademarks of Cyteir Therapeutics, Inc.


Michele Parisi
For Cyteir Therapeutics
[email protected]