A biotech company developing drugs that treat cancers by controlling gene expression is shifting its focus following the failure of a drug that it was testing in patients with solid tumors.
Cambridge, Massachusetts-based Syros said Thursday that data from the expansion portion of its Phase I study of SY-1365, an intravenous CDK7 inhibitor, did not show that any patients had achieved an objective response to treatment. The best response was stable disease in 13 of 31 patients evaluable for efficacy, meaning that their tumors did not grow further, but did not shrink either. The study recruited patients with cancers of the breast, ovaries as well as advanced solid tumors, who were enrolled into single-agent and combination cohorts.
Market Trends to Watch for Health Systems and Their Specialty Pharmacies
The future looks bright for the integrated specialty pharmacy model – for health systems, providers, and most importantly, for patients.
Shares of Syros were down 32.3 percent on the Nasdaq following the news.
The company has consequently decided to shift its focus from SY-1365 to another drug, the oral CDK7 inhibitor SY-5609, which it said inhibits CDK7 more selectively and potently than SY-1365 and in preclinical testing has shown greater anti-tumor activity. The company plans to discontinue SY-1365’s development and launch a Phase I study of SY-5609 in the first quarter of 2020.
Patients in the single-agent expansion cohorts had started out receiving SY-1365 at 80mg per square meter of body area twice weekly, while those in the combination cohorts had received it at 53mg per meter squared once weekly. Side effects thought to be related to IV administration – including headache, nausea and vomiting – prompted the company to look at extended infusion times across all the cohorts and lower doses in the single-agent cohorts.
However, Syros is of the view that more frequent dosing or a higher dose that would mean lengthening infusion time in order to make the drug more tolerable would be required to sustain the level of CDK7 target coverage necessary for sufficient clinical activity – either of which would result in a dosing schedule overly burdensome for patients. SY-5609 can better address that dilemma, the company said.
The Funding Model for Cancer Innovation is Broken — We Can Fix It
Closing cancer health equity gaps require medical breakthroughs made possible by new funding approaches.
The lack of objective responses in the trial indicates that the dose reductions and extended infusion times may have compromised efficacy, wrote Cowen analyst Phil Nadeau, in a note to investors Thursday. The news came as a disappointment, given that the preclinical and Phase I dose-escalation data had indicated that SY-1365 would be more efficacious and safer.
Photo: Jane1, Getty Images