Quark, Pfizer to start new mid-stage glaucoma drug trial

Quark Pharmaceuticals Inc. and Pfizer Inc. expanded a nearly 6-year-old drug-development deal to include a mid-stage trial of their RNA interference treatment in a type of glaucoma. Fremont-based Quark said Tuesday that the deal could earn it up to $165 million more in payments from Pfizer around the experimental drug, called PF-655.