LABORATORY AND CLINICAL STUDIES ON RU 28965

• Published in: CHEMOTHERAPY Vol. 36; no. Supplement4; pp. 293 - 300
• Main Authors: KUMADA, TEPPEI, SHIMIZU, KIHACHIRO, SAKAMOTO, YASUMI, KATAHIRA, JUNICHI, FUKUDA, TOMOKO
• Format: Journal Article
• Language: English; Japanese
• Published: Japanese Society of Chemotherapy 1988; 公益社団法人 日本化学療法学会
• ISSN: 0009-3165; 1884-5894
• DOI: 10.11250/chemotherapy1953.36.Supplement4_293

We carried out laboratory and clinical studies on RU 28965, a new macrolide antibiotic, with the following results, De. crease in hemoglobin was noted in about 50% of subjects in a phase I study and in about 20% of patients treated with RU 28965. Accordingly, the effect of RU 28965 on hematopoietic stem cells was investigated by in vitro clonal assay using the methylcellulose culture method. RU 28965 inhibited only hematopoietic stem cells of red blood cells (CFU-E) at concentrations above 5μg/ml. RU 28965 was administered to 22 patients: 9 with acute bronchitis, 8 with pneumonia, and 1 each with laryngopharyngitis, acute tonsillitis, chronic bronchitis, diffuse panbronchiolitis and necrotizing lymphadenitis. Clinical response was excellent in 2 patients, good in 11, fair in 6, poor in 1 and unknown in 1. The clinical efficacy rate was 61%. The patient with lymphadenitis was excluded from the analysis, since this disease did not meet the inclusion criteria. Only one adverse reaction, gastric discomfort, was noted. RU 28965 has been reported to produce high plasma concentrations. Although its concentration in bone marrow is not known at present, patients treated with an increased dose of RU 28965 may need careful monitoring of its effects on the hematopoietic system.