The most common non-hematologic toxicities were mild grade 1 and 2 nausea, diarrhea and vomiting. Blood concentrations of the active metabolite of Telintra tablets increased with dose levels.
The objectives of the trial were to evaluate the safety and pharmacokinetics of Telintra tablets (also known as TLK199 tablets), and obtain preliminary indications of efficacy. The trial enrolled 45 patients and included all WHO classifications of myelodysplastic syndrome (MDS). Patients received one of 10 dose levels of Telintra tablets taken daily for seven days followed by two weeks of follow-up. Patients could receive planned therapy up to six months (eight cycles) until MDS progression or unacceptable toxicity.
A total of 39 patients were evaluable for efficacy by objective hematologic improvement (HI) criteria. A dose-response curve was observed, with the majority of responses occurring in patients treated at the higher dose levels. Across all doses, neutrophil (HI-N) responses were observed in 21% (four of 19) patients with neutrophil cytopenias. Seven of 21 patients (33%) with platelet cytopenias had HI-P. Among the 29 patients with erythroid cytopenias, HI-E was observed in six patients (21%). Some patients achieved red blood cell transfusion independence or a reduction in transfusion requirements, and one patient achieved platelet transfusion independence. One patient had a complete cytogenetic response.