Vertex tracks encouraging IIa data for JAK3 rheumatoid arthritis drug

Vertex ($VRTX) continues to rack up promising results in the clinic. Investigators for the biotech outlined some positive data curried from their Phase IIa study of VX-509, a potential new JAK3 therapy for rheumatoid arthritis. The biotech reported that 66% of the patients taking a 150-mg dose experienced a better-than-20% improvement in signs and symptoms of the disease, compared to 29% in the placebo arm. Almost half of the patients in the treatment arm reported a better than 50% improvement, compared to 7% in the placebo group.

"These early results are encouraging and provide strong support that the selective targeting of JAK3 by VX-509 may represent a new approach to the treatment of RA and other autoimmune and inflammatory diseases," said Peter Mueller, the global R&D chief for Vertex. "In people who received VX-509, the signs and symptoms of RA continued to improve throughout the 12-week study. We look forward to initiating a longer-duration trial to explore the potential for additional improvements in RA activity and to further establish the safety profile of VX-509."

Vertex's next step for this program will be a 6-month Phase IIb study to evaluate once-daily and twice-daily doses of VX-509 in combination with methotrexate, a standard therapy for RA.

Researchers noted that infections were the most frequently cited class of adverse reactions in the drug as well as the placebo groups. Other adverse events tracked included nausea, headache and increased alanine transaminase, an enzyme found mostly in the liver. Five percent of the patients discontinued treatment due to adverse events in the placebo group compared to 8% of the patients who received VX-509.

- check out the Vertex release