Syros Presents New Preclinical Combination Data on SY-1365 and First Preclinical Data from Oral CDK7 Inhibitor Program at EORTC-NCI-AACR Meeting - Seite 2

Consistent with the proposed mechanism-of-action, SY-1365 demonstrated synergy with carboplatin in ovarian cancer cell lines and demonstrated greater anti-tumor activity in combination with carboplatin in xenograft models of ovarian cancer than either agent alone.

Syros is currently conducting a Phase 1 clinical trial assessing the safety and efficacy of SY-1365 as a single agent and in combination with standard-of-care therapies in multiple ovarian and breast cancer patient populations. The ongoing trial includes a study cohort evaluating SY-1365 in combination with carboplatin in ovarian cancer patients who have relapsed after one or more prior therapies. Additional details about the trial can be found using the identifier NCT03134638 at www.clinicaltrials.gov.

Preclinical Data from Oral CDK7 Inhibitor Program
Syros created a suite of highly selective and potent orally available CDK7 inhibitors. The preclinical data at EORTC-NCI-AACR detail for the first time the selectivity, potency and anti-tumor activity of these inhibitors. Using a representative member of Syros’ suite of oral CDK7 inhibitors, these data show:

• 200- to 1,200-fold greater selectivity for CDK7 over other members of the CDK family, including CDK2, CDK9 and CDK12.
• Robust anti-proliferative activity in triple negative breast cancer and ovarian cancer cell lines, which was associated with the induction of apoptosis and cell cycle arrest.
• Strong correlation between biochemical potency, CDK7 target engagement and tumor growth inhibition.
• Substantial anti-tumor effects in multiple cell-line and patient-derived xenograft models of triple negative breast and ovarian cancers.

These data helped support the selection of SY-5609 as the Company’s next development candidate. Syros is currently advancing SY-5609 into Investigational New Drug (IND) application-enabling preclinical studies.

The poster presentations on the SY-1365 preclinical combination data and on the oral CDK7 inhibitor program are now available on the Publications and Abstracts section of the Syros website at www.syros.com.

About Syros Pharmaceuticals
Syros is pioneering the understanding of the non-coding regulatory region of the genome to advance a new wave of medicines that control the expression of genes. Syros has built a proprietary platform that is designed to systematically and efficiently analyze this unexploited region of DNA to identify and drug novel targets linked to genomically defined patient populations. Because gene expression is fundamental to the function of all cells, Syros’ gene control platform has broad potential to create medicines that achieve profound and durable benefit across a range of diseases. Syros is currently focused on cancer and monogenic diseases and is advancing a growing pipeline of gene control medicines. Syros’ lead drug candidates are SY-1425, a selective RARα agonist in a Phase 2 clinical trial for genomically defined subsets of patients with acute myeloid leukemia and myelodysplastic syndrome, and SY-1365, a selective CDK7 inhibitor in a Phase 1 clinical trial for patients with ovarian and breast cancers. Syros is also developing a deep preclinical and discovery pipeline, including SY-5609, an oral CDK7 inhibitor, as well as programs in immuno-oncology and sickle cell disease. Led by a team with deep experience in drug discovery, development and commercialization, Syros is located in Cambridge, Mass.