It’s been a strange up and down ride for PARP inhibitors, a relatively new class of cancer drugs.

Named for the tumor protein they target, PARPs rebounded after a big clinical setback in 2011 and have been at the center of many buyouts and big alliances—Pfizer and Medivation, GlaxoSmithKline and Tesaro, AstraZeneca and Merck. Four of them have received FDA-approval since 2014 to treat subsets of patients with ovarian and breast cancer. They’re typically used in “maintenance” settings, meant to keep cancer at bay after chemotherapy.

Yet PARP inhibitors have been a tough sell. Developers have had… Read more »