Thymopentin (TP-5) in the treatment of rheumatoid arthritis.

A randomized control trial of TP-5 in rheumatoid arthritis is reported. In a multicentre study, 76 patients were treated with TP-5 50 mg or placebo three times a week for 3 weeks as a slow intravenous injection, and followed for 7 weeks. Clinical parameters such as the Ritchie index and sum score of swollen joints improved significantly on TP-5 compared to placebo. Laboratory parameters did not change but an increased skin test score to common recall antigens was observed. Toxicity was minimal. TP-5 is a potentially useful agent in the treatment of rheumatoid arthritis, although further studies are required to determine the optimal treatment regimen.