Abstract

MY-1 is a new biological response modifier, which consists of heat-denatured nucleic acids, extracted and purified from Mycobacterium bovis BCG. A multi-center clinical phase II study of this drug was performed at 10 institutes on patients with Adult T-cell leukemia (ATL) . All the patients were anti-HTLV-I antibody positive and had the cutaneous type ATL. The drug was administered by a subcutaneous injection with a daily dose of 15 or 30mg. Efficacy was evaluated by using the criteria of the Japanese Society for Skin Cancer.
Of a total of 24 eligible cases, complete response (CR) was observed in 5 and partial response (PR) in 7. Then, overall response rate was 50% (12/24) .
Adverse reactions, such as fever, leucopenia, and hepatic disorder were rarely observed. In cases where they were observed, none were serious and all were reversible.
In conclusion, MY-1 was considered to be a useful drug in the treatment of cutaneous type ATL.