Seven years after licensing BTK inhibitor from Biogen, beleaguered pennystock biotech partner concedes defeat
A BTK inhibitor Biogen punted out of its pipeline years ago has flopped its first clinical test.
Sunesis Pharma said it would not be taking vecabrutinib into the Phase II portion of its Phase Ib/II trial after reviewing initial data that suggest limited efficacy even at the highest dose. The trial had enrolled adult patients with relapsed/refractory chronic lymphocytic leukemia (CLL) and other B-cell malignancies. The safety profile was “excellent”; it just didn’t seem to have much of an effect.
Dayton Misfeldt, the Bay City Capital VC who’s been interim CEO for more than two years, summed it up this way:
One partial remission was observed after 11 treatment cycles in a CLL patient treated in Cohort 5 (300 mg BID) and a number of patients treated across the dose range explored (25 mg to 500 mg BID) saw stable disease; however, no other remissions have been observed.
The Phase Ib program will continue while Sunesis execs decide on the drug’s fate. Shares of the South San Francisco company on the Nasdaq — a pennystock — plummeted 43.68% to $0.35 pre-market.
For now, Sunesis will shift its focus and resources to a PDK-1 inhibitor dubbed SNS-510 — a process that should be familiar to the company by now.
When it went public in 2005, the lead product candidate was SNS-595 (vosaroxin), a cell-cycle inhibitor later positioned for leukemia. Regulators spurned their Phase III data and Sunesis ended up out-licensing it to Denovo Biopharma, which specializes in finding applicable subgroups for drugs that have completed trials with “unsatisfactory efficacy.” Not much came out of the second project to develop an Aurora kinase inhibitor, either.
The current pipeline of two consists entirely of assets originating from a collaboration with Biogen, who was also an equity holder. Aside from vecabrutinib, a non-covalent inhibitor of BTK that promised to help Imbruvica-resistant patients, SNS-510 targets PI3K-dependent and PIP3-independent pathways.
With Takeda on board as a partner, an IND is in the works for the end of 2020. The cash reserves should be enough to get them there — but likely not that much beyond.