An international team of researchers has performed a follow–up analysis based on a large clinical study of a maintenance therapy for patients with multiple myeloma. Philip McCarthy, MD, of Roswell Park Cancer Institute was principal investigator of a phase III study that showed that treatment with lenalidomide following autologous hematopoietic stem cell transplant improved both progression–free survival and overall survival for newly diagnosed multiple myeloma patients. He is also first author on an updated analysis presented during the American Society of Clinical Oncology (ASCO) 53rd Annual Meeting that adjusts the data to account for the impact of crossover from the placebo arm to the treatment arm among a group of study participants.

The phase III study, Alliance for Clinical Trials in Oncology study CALGB/ECOG/BMT–CTN 100104, was unblinded in December 2009 following the release of interim study results demonstrating a progression–free–survival benefit from lenalidomide maintenance. Patients receiving no lenalidomide maintenance — those in the placebo arm — who showed no evidence of disease progression were offered active treatment with lenalidomide (Revlimid). The majority of eligible patients opted to cross over to receive lenalidomide maintenance therapy.

For the current analysis, the research team examined the effect of lenalidomide on both overall and progression–free survival, adjusting for the impact of the delayed initiation of treatment using an approach known as rank–preserving structural failure time modeling. When accounting for the placebo–arm patients who crossed over to lenalidomide treatment, they report, the maintenance treatment effect on both progression–free and overall survival improved.

“It’s notoriously difficult to tease out the effects of crossover and to fairly compare the impact of a medication in groups who weren’t treated for the same length of time. However, this analysis shows that the lenalidomide maintenance effect increased when we accounted for the placebo crossover effect,” says Dr. McCarthy, who is Director of the Blood and Marrow Transplant Center at Roswell Park.

The new analysis was performed in collaboration with researchers from the Alliance for Clinical Trials in Oncology, Eastern Cooperative Oncology Group, Blood and Marrow Transplant Clinical Trials Network, Duke University School of Medicine, BresMed Health Solutions Ltd., Celgene Corp., the Abramson Cancer Center and Dana–Farber Cancer Institute.

The poster was titled, “CALGB/ECOG 100104 (Alliance) study: Lenalidomide (LEN) vs placebo (PBO) maintenance (maint) after stem cell transplant (SCT) for patients (pts) with multiple myeloma—Overall survival (OS) and progression–free survival (PFS) adjusted for treatment (tx) crossover (XO).”