Long-term follow-up data on patients treated with pentostatin (Nipent) were presented at the 39th Annual Meeting of the American Society of Hematology in San Diego, California. Pentostatin is currently indicated in the United States for first-line treatment of hairy cell leukemia.
Among 209 hairy cell leukemia patients successfully treated with pentostatin in a previously published randomized phase III study, Kaplan-Meier estimates indicated 90% survival at 5 years and 87% survival at 8 years with a median follow-up of 7.8 years. Relapse-free survival estimates for the 173 patients who achieved a complete response with the drug are 86% at 5 years and 76% at 8 years.
The study was presented by investigators from numerous institutions, including the National Cancer Institute, Southwest Oncology Group Statistical Center, and Johns Hopkins University.
We are genuinely pleased with the strength of this data from such a large group of patients for this disease, said Dr. Luigi Lenaz, Senior Vice President and Medical Director of SuperGen. Not only can we induce a very high complete response rate, but these responses are extremely durable.
In all, 241 hairy cell leukemia patients (154 previously untreated patients and 87 patients who did not respond to other drugs) were treated with pentostatin every 2 weeks for 6 to 12 months, and 209 survived. Among the 241 patients, 25 malignancies other than hairy cell leukemia were subsequently diagnosed. Second malignancies have been reported in both untreated hairy cell leukemia patients and in patients treated with nucleoside analogs, such as pentostatin.