First Patient Enrolled in Phase 1 Clinical Trial of SY-1365 in Breast, Other Solid Cancers

First Patient Enrolled in Phase 1 Clinical Trial of SY-1365 in Breast, Other Solid Cancers

Syros Pharmaceuticals has enrolled the first patient in a Phase 1 clinical trial assessing the effectiveness and safety of SY-1365 as a treatment for patients with advanced solid tumors, such as triple-negative breast cancer, small-cell lung cancer, and ovarian cancer.

SY-1365 is a first-in-class selective inhibitor of a protein called cyclin-dependent kinase 7 (CDK7) that helps solid-tumor cancers survive.

CDK7 is known as a transcription factor protein because it controls the expression of other proteins. The usual definition of expression is that it’s the process by which information from a gene is used to create a functional product like a protein. Cancers that transcription factors impact are known as transcriptionally dependent cancers.

“SY-1365 represents a promising new approach for treating a number of aggressive cancers that have eluded treatment with other targeted approaches,” Dr. Anthony W. Tolcher, the trial investigator, said in a news release. “Certain cancers are particularly dependent on high expression of transcription factors for their growth and survival, and SY-1365 has shown substantial anti-tumor activity in preclinical models of these cancers. We’re pleased to have enrolled the first patient in this clinical trial and look forward to further investigating SY-1365 for patients with these difficult-to-treat solid tumors.”

The trial (NCT03134638) is expected to include about 70 patients with advanced solid tumors.

The two-part, dose-escalation study will assess the safety and tolerability of increasing doses of SY-1365. The objective is to identify the optimal dose for a Phase 2 study that will further assess the therapy’s effectiveness.

The dose-escalation stage of the study is open to patients who would be unable to benefit from standard preventive or curative treatments are who can no longer respond to them. The dose that is chosen in the dose-escalation stage will be administered to more patients in the Phase 1 study with triple-negative breast cancer, small-cell lung cancer, and ovarian cancer. The objective will be to further assess the dose’s safety and effectiveness.

“Patients with triple negative breast, small cell lung and ovarian cancers, as well as other transcriptionally dependent cancers, are in dire need of better treatment options,” said Dr. David A. Roth, Syros’ chief medical officer. “Based on the strong preclinical data, we believe SY-1365 could provide a meaningful benefit for patients with these cancers. We have designed our Phase 1 trial to efficiently assess early proof of mechanism during the dose escalation phase and early anti-tumor activity by focusing the expansion phase of the trial on a set of transcriptionally dependent tumors that are most sensitive to CDK7 inhibition and for which early anti-tumor activity may be observed.”