Spring Bank Pharmaceuticals is pulling the plug on its lead program, an antisense drug for hepatitis B, due to safety concerns, including one patient death. The company is on the hunt for a partner to license the program and will pivot its own efforts toward its STING portfolio for the treatment of cancer and inflammatory disease.
The move comes one month after Spring Bank stopped dosing in a phase 2b study of the drug, inarigivir, because patients showed signs of liver damage. At the time, the Hopkinton, Massachusetts-based company announced that three patients showed “evidence of hepatocellular dysfunction” and high levels of the liver enzyme alanine transaminase (ALT), “potentially consistent with liver injury.”
“We are deeply saddened by the death of a patient in our CATALYST 2 trial. Because we are guided by an overriding interest in protecting patients, we have made the difficult decision to discontinue the further development of inarigivir for the treatment of HBV at Spring Bank,” said CEO Martin Driscoll, in a statement. “We will continue to work in close collaboration with external experts and our clinical study investigators to provide the care necessary for all study patients and will continue to conduct a series of investigative actions to better understand the unexpected serious adverse events observed in our Phase 2b program.”
Spring Bank has started discussions with potential partners to take inarigivir off its hands. In the meantime, the biotech reckons that ceasing hep B R&D will give it runway into late 2022 to carry forward its other programs.
Those include a STING agonist, SB 11285, which is in a phase 1a/1b study in cancer, a STING antagonist for inflammatory disease and a STING agonist antibody-drug conjugate (ADC) program.
“By the end of 2020, we plan to generate sufficient data from our Phase 1a/1b IV STING agonist program to enable advancement into a Phase 2 clinical trial, initiate IND-enabling activities for an orally-available STING antagonist and progress our pipeline of STING agonist ADCs,” Driscoll said in the statement.
Spring Bank isn’t the only company to can a hep B program after unexpected side effects. In October, Arbutus Biopharma abandoned the oral capsid inhibitor it was developing for the treatment of chronic hep B after healthy volunteers in a phase 1 study developed acute hepatitis.