Federal health advisers said Wednesday that a first-of-a-kind drug from Pfizer appears to be safe and effective for patients with rheumatoid arthritis, though they recommended follow-up studies to gauge the pill’s long-term side effects. The Food and Drug Administration’s panel of arthritis experts voted 8-2 in favor of Pfizer’s tofacitinib for patients who have not responded to one or more other drugs. The FDA is not required to follow the group’s advice, though it often does. A final decision is expected in August.