Arcus Biosciences Inc. and partner Gilead Sciences Inc. are scrapping phase III work with anti-TIGIT antibody domvanalimab after an independent data monitoring committee said the drug will fail in gastric and esophageal cancers.
As developers in the oft-troubled TIGIT class forge onward, Roche Holding AG’s Genentech unit provided an unfavorable update July 5 on the phase II/III Skyscraper-06 study testing anti-TIGIT candidate tiragolumab plus Tecentriq (atezolizumab) and chemotherapy vs. Keytruda (pembrolizumab, Merck & Co. Inc.) and chemo as first-line treatment for non-squamous non-small-cell lung cancer (NSCLC).
The narrative of TIGIT-targeting immunotherapy development, beset by negative news in recent months, has found a positive plotline again, thanks to what Roche Holding AG referred to as “an inadvertent disclosure” of a second interim analysis from the phase III Skyscraper-01 study testing anti-TIGIT candidate tiragolumab with anti-PD-L1 antibody Tecentriq (atezolizumab) in non-small-cell lung cancer.
With much-awaited readouts from their broad oncology-focused collaboration due later this year, Arcus Biosciences Inc. and Gilead Sciences Inc. have decided to expand efforts into the inflammatory disease space via an early stage research agreement that could be worth as much as $1 billion. Terms include a $35 million up-front payment to Arcus, which is making its first move beyond oncology.
While new data from Arcus Biosciences Inc. and Gilead Sciences Inc. didn't do much to calm an unsteady development corridor, researcher, developers and analysts still hold out hope for the TIGIT pathway. The Arcus-Gilead randomized phase II study combining anti-TIGIT domvanalimab and anti-PD1 antibodies for treating first-line, metastatic non-small-cell lung cancer produced positive results, including improvements in median progression-free survival (PFS) and six-month landmark PFS rates vs. monotherapy. But a hefty dent in Arcus' shares provide a reminder of TIGIT’s fragility as a field, and a reminder of the phase III failure in May for Roche Holding AG unit Genentech Inc.'s anti-TIGIT immunotherapy tiragolumab, which dragged down the share value of several other class entrants. Arcus stock (NASDAQ:RCUS) dipped deeply on Dec. 20 on the new data’s release, but rallied on Dec. 21 by closing 7.5% upward at $22.15 each.
Wall Street must wait a while longer to find out if Gilead Sciences Inc. will exercise its $275 million option for Arcus Biosciences Inc.’s TIGIT binder, domvanalimab. Meanwhile, investors took heart from an optimistic – albeit vague – interim report on the phase II ARC-7 trial.
