Post-transplant consolidation therapy using thalidomide alone for the patients with multiple myeloma: a feasibility study in Japanese population

Tomoki Ueda, Rioko Iino, Kenji Yokoyama, Shinichiro Okamoto, Keiko Asakura, Yuiko Tsukada, Jo Ishizawa, Eri Matsuki, Yasuo Ikeda, Yutaka Hattori

In order to test for improved survival following autologous transplantation (ASCT), we conducted a prospective clinical trial of post-ASCT thalidomide therapy in Japanese patients with multiple myeloma (MM). Twenty-five newly diagnosed patients received double or single ASCT with high-dose melphalan (200 mg/m(2)). Two months after stem cell infusion, if the patients failed to achieve a near-complete response, thalidomide was administered at 200 mg/day until disease progression or occurrence of intolerable adverse events. Seventeen patients were in partial response or minimal response after ASCT and received thalidomide alone. Their median progression-free survival (PFS) from ASCT was 17.4 months, and the median overall survival (OS) was 42.9 months. Some patients with normal karyotype experienced durable disease stabilization for over 5 years. Five patients who exhibited high-risk chromosomal changes such as t(4;14) or deletion of chromosome 13 or 17 showed very short PFS and OS compared with those who did not. Observed grade 3 or 4 toxicities included infection in three patients, hematological toxicities in three, and gastrointestinal toxicities in two, but there was no grade 3 or higher peripheral neuropathy, probably due to appropriate dose modifications. This long-term prospective study is the first to demonstrate the feasibility of post-ASCT thalidomide therapy in Japanese patients with MM.