NEW YORK (AP) — Shares of OSI Pharmaceuticals Inc. skidded to an annual low Monday, as trial results for a OSI’s Tarceva led one analyst to downgrade the stock. Over the weekend, OSI reported results from a late-stage trial that tested Tarceva and another cancer drug, Avastin, as a primary treatment for advanced non-small cell lung cancer. Tarceva is already approved as a secondary treatment for the disease. OSI’s partner, Roche, said median survival for patients who received the combination of Tarceva and Avastin was 4.8 months. Patients who took Avastin and a placebo had median survival of 3.7 months. The trial was stopped in February when monitors said it was clear that the drugs were effective in halting the progression of the disease. The results were presented Saturday at the annual meeting of the American Society of Clinical Oncology in Orlando. But Thomas Weisel Partners analyst Stephen Willey said he thinks the Tarceva-Avastin combination probably will not be very popular because of the side effects that have appeared in clinical trials. He lowered his rating on OSI to “Market Weight” from “Overweight,” and reduced his price target to $36 per share from $48. Willey said Tarceva sales growth is weak, and unless the drug gets additional approvals, it is likely to remain weak.