Syros Pharmaceuticals Presents New Data Demonstrating Significant Anti - Tumor Activity of its Selective CDK7 Inhibitor in Preclinical Models of Acute Myeloid Leukemia

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Syros Pharmaceuticals today announced that SY-1365, a first-in-class potent and selective cyclin-dependent kinase 7 (CDK7) inhibitor, was observed to induce durable tumor regression and prolong survival in in vivo models of acute myeloid leukemia (AML). These data were presented at the American Association of Cancer Research (AACR) Annual Meeting in New Orleans. Based on the strong efficacy and safety data, Syros selected SY-1365 as its development candidate and plans to file an Investigational New Drug (IND) application with the U.S. Food and Drug Administration in the second half of 2016 with the goal of initiating a Phase 1/2 clinical study in acute leukemia in the first half of 2017.

“Up until now, creating medicines to control important disease causing transcription factors has been a major challenge in cancer drug development. SY-1365, our first-in-class CDK7 inhibitor, highlights the potential of our pioneering platform to produce drugs that can selectively modulate these transcription factors” Tweet this “Up until now, creating medicines to control important disease causing transcription factors has been a major challenge in cancer drug development. SY-1365, our first-in-class CDK7 inhibitor, highlights the potential of our pioneering platform to produce drugs that can selectively modulate these transcription factors,” said Nancy Simonian, M.D., Chief Executive of Syros. “Certain hematologic and solid tumor cancers, including AML, are dependent on transcription factors for their growth and survival and have been shown to be particularly dependent on CDK7. Results from preclinical studies demonstrate that SY-1365 lowers the levels of these disease causing transcription factors and, in so doing, may treat diseases that have eluded other genomics-based approaches and provide a profound and durable benefit for patients with these difficult-to-treat cancers.”

In the preclinical studies presented at AACR, SY-1365 was observed to preferentially kill cancer cells over non-cancerous cells and significantly prolong survival in patient-derived xenograft (PDX) models of AML. In the in vitro and in vivo studies, SY-1365 induced:

Tumor regression in 100 percent of treated mice in a cell-line derived xenograft model of AML; tumor regression was maintained through the end of the 38-day study.

Strong survival benefit, with 80 percent of treated mice alive at the end of the 8-week study in a PDX model of treatment-resistant AML; by contrast, none of the untreated mice survived beyond 4-1/2 weeks.

Rapid and dose-dependent apoptosis in AML cell lines treated with SY-1365 while having little to no effect on non-cancerous cells.

Potent and selective inhibition of CDK7, with only six other kinases, none of which are in the CDK family, exhibiting greater than 90 percent binding when profiled across a panel of 468 kinases at a concentration of 1μM.

Minimal effect on blood cell counts in in vivo models, including white blood cells, lymphocytes, neutrophils and reticulocytes, demonstrating a more favorable profile than a non-selective CDK inhibitor.

Reduced expression of cancer-contributing genes associated with specialized regulatory regions of DNA known as super-enhancers, including transcription factors and the oncogenes MYB and MYC, in an AML cell line.

Synergistic activity when combined with other targeted agents in AML, including Flt3, Bcl-2 and pan-Brd inhibitors.

Syros’ selective CDK7 inhibitors, including SY-1365, have been observed to delay tumor progression in additional in vivo models of transcriptionally addicted cancers, including acute lymphoblastic leukemia (ALL), MYCN-amplified neuroblastoma, small cell lung cancer and triple negative breast cancer.

About Syros Pharmaceuticals

Syros Pharmaceuticals is pioneering the understanding of the non-coding region of the genome to advance a new wave of medicines that control expression of disease-driving genes. Syros has built a proprietary platform that is designed to systematically and efficiently analyze this unexploited region of DNA in human disease tissue to identify and drug novel targets linked to genomically defined patient populations. Because gene expression is fundamental to the function of all cells, the Company’s gene control platform has broad potential to achieve profound and durable benefit across a range of diseases. Syros is focused on cancer and immune-mediated diseases and is advancing a growing pipeline, including its lead drug candidates SY-1425, a selective RARα agonist for genomically defined subsets of patients identified by its platform, for a range of cancers including acute myeloid leukemia and myelodysplastic syndrome, and SY-1365, a selective CDK7 inhibitor for a range of blood cancers and solid tumors. Led by a team with deep experience in drug discovery, development and commercialization, Syros is located in Cambridge, Mass.