Results from an interim analysis of a Phase III trial show that maintenance therapy with lenalidomide slowed disease progression by 54 percent among patients with multiple myeloma who had prior high-dose chemotherapy and an autologous stem cell transplant.

"These results are very promising. If confirmed in the final analysis, they suggest that maintenance therapy with lenalidomide can improve quality of life in patients with myeloma by delaying the need for more intensive therapy to treat a relapse," said Michel Attal, Ph.D., professor of hematology at Purpan Hospital in Toulouse, France and the lead author of the study, which was conducted by the French-Speaking Intergroup for Myeloma (Intergroup Francophone du Myelome). Final data on progression-free survival and overall survival are expected to be reported in December 2010.

Multiple myeloma is treated with high-dose chemotherapy and autologous stem cell transplantation (ASCT). Despite this aggressive approach, however, more than 90 percent of patients eventually experience a cancer relapse.

Prior research has shown that maintenance therapy with the chemically similar drug thalidomide can delay myeloma relapse, but this drug has significant toxic effects on the nervous system and was only effective in a limited group of patients.

Lenalidomide is an oral drug that is already used to treat myeloma that recurs or persists despite prior therapy. In this study, investigators compared the progression-free survival between 307 patients who were randomly assigned to receive maintenance lenalidomide until relapse and 307 patients who received a placebo. All patients had previous treatment with high-dose therapy and ASCT within six months of randomization, followed by two months of lenalidomide "consolidation" therapy (lenalidomide treatment after initial therapy to achieve a complete remission; consolidation therapy uses a higher dose of lenalidomide than maintenance therapy).

Lenalidomide maintenance therapy improved three-year progression-free survival: 68 percent of patients in the lenalidomide group did not experience disease progression, compared with 35 percent of the placebo group. This benefit was observed whether or not patients had achieved a complete response after ASCT. Two-year overall survival was similar in both groups (95 percent). Maintenance lenalidomide was well tolerated.

Disclosures: Michel Attal, Consultant or Advisory Role, Celgene, Janssen-Ortho, Research Funding, Celgene; Thierry Facon, Consultant or Advisory Role, Celgene, Janssen-Cilag; Philipe Moreau, Consultant or Advisory Role, Celgene, Janssen-Cilag, Research Funding, Janssen-Cilag; Herve Avet-Loiseau, Consultant or Advisory Role, Celgene, Janssen-Cilag; Jean Harousseau, Consultant or Advisory Role, Celgene, Janssen-Ortho. Research Funding, Janssen-Ortho.

This study was presented at ASCO's 46th Annual Meeting in Chicago.

Research Funding Provided by: programme hospitalier de recherche clinique