Phase I study of perifosine monotherapy in patients with recurrent or refractory neuroblastoma.

Abstract

Perifosine is an alkylphospholipid analog that inhibits or modulates signaling through signal transduction pathways such as Akt, which is enhanced in neuroblastoma (NB) by activation of tyrosine kinase receptors. We conducted a phase I study of perifosine in Japanese patients with recurrent or refractory NB. All patients enrolled were over 2 years of age; all had refractory or relapsed NB and a performance status of greater than 50%. Perifosine was orally administered at a loading dose (100-300mg) on day 1 and at a maintenance dose (50-150mg) from day2 onward. Dose-limiting toxicity (DLT) and pharmacokinetics were assessed in Step 1 and safety and efficacy in Step 2. Nineteen patients were recruited. No DLT was observed. Adverse reactions occurring in more than 30% of the patients were vomiting (63%), nausea (53%), and diarrhea (37%). The mean plasma concentration of perifosine was 27.5 ± 9.8μM on day 15 and 27.3 ± 11.5μM on day 29. The response rate (RR) in 18 patients evaluable according to modified International Neuroblastoma Response Criteria was 0%; the disease control rate (DCR) was 56%. Median progression-free survival (PFS) was 122 days. In 11 patients evaluable according to the Response Evaluation Criteria in Solid Tumors, the RR and DCR were 9% and 55%, respectively. The median PFS was not reached. Perifosine monotherapy was well tolerated in Japanese patients with recurrent/refractory NB. Further investigations in combination with other anticancer or molecular targeted agents are warranted.