An evaluation of lenalidomide’s (Revlimid) long-term ‘maintenance’ efficacy for patients with multiple myeloma has demonstrated considerable improvements from the time to progression and overall survival for those suffering from this often-fatal form of hematologic cancer.

The May 10 issue of the New England Journal of Medicine reports that Dr. Philip L. McCarthy, MD, Professor of Oncology at the Roswell Park Cancer Institute (RPCI) and his team observed that administering lenalidomide (Revlimid) after induction therapy and hematopoietic stem-cell transplant decreased patients’ risk of disease progression to 20%, as compared to 44% in those who received placebo.

In April 2005, research leader Dr. McCarthy, and his team initiated the Cancer and Leukemia Group B (CALGB) 100104 study, a phase III randomized, double blind, placebo-controlled clinical trial that involved 460 patients from 47 U.S. transplant centers, with a mean age of 59 years, who had previously received autologous hematopoietic stem-cell transplants and whose disease was stable, i.e. non-progressive.

The team randomly assigned 321 patients to receive lenalidomide and 229 patients to receive placebo. The primary endpoint of the study was determined as time to disease progression. In December 2009, at the study’s primary endpoint, the participants’ assignments and responses to date were unblinded, demonstrating a statistically important difference between both groups. 86 of 128 eligible patients switched from the placebo group into the lenalidomide group after January 2010.

Overall, the results showed that lenalidomide therapy extended the time to disease progression by 19 months, which also included the majority of placebo patients without progression who switched over into the lenalidomide group. In comparison with other treatments for multiple myeloma, like thalidomide, the researchers observed the treatment to be fairly well tolerated, although patients in the lenalidomide group suffered more hematologic toxicity, in particularly neutropenia compared with those in the placebo group.

At the 34-months follow up in October 2011, when the team re-analyzed the data, they noted that amongst those in the lenalidomide group 37% suffered disease progression or had passed away, compared with 58% of patients in the placebo group.

Dr. McCarthy, who is also Director of RPCI’s Blood & Marrow Transplant Program, says:

“These findings fill a gap that existed previously in terms of data on whether maintenance therapy with lenalidomide prolongs the time to disease progression after initial therapy. We now have evidence that it does, in this and the two other lenalidomide studies that are presented in this issue of the Journal. This shows that patients with multiple myeloma now have options for prolonging the response to initial therapy. The next steps will be trying to improve on these responses by adding new agents that may prove even more effective in combination with lenalidomide following transplant.”

The researchers also observed a benefit in overall survival, with a 15% death rate in patients in the lenalidomide group at the average follow up of 34 months compared with a 23% death rate amongst those in the placebo group.

McCarthy and his team write:

“The median overall survival among patients who required therapy before 1996 was approximately 3 years. In the era of new agents and autologous hematopoietic stem-cell transplantation, the median overall survival after transplantation is close to 8 years.”

A comparison between both group showed that the cumulative cases of second primary cancer was higher in the lenalidomide group than in the placebo group, although the reverse was true in terms of the cumulative incidence of progressive disease and mortality, which was higher in the placebo group than in the lenalidomide group.

Group Chair of the Alliance for Clinical Trials in Oncology, Monica M. Bertagnolli, MD, Chief of the Division of Surgical Oncology at Brigham and Women’s Hospital and Professor of Surgery at Harvard Medical School concluded:

“The results of CALGB 100104 ultimately show that the long-term administration of lenalidomide is feasible. This positive outcome brings us closer to providing better treatment for patients with multiple myeloma. Additionally, this trial demonstrates the benefits of cooperative group research where patients participating in clinical trials help lead the way to important discoveries.”

Written By Petra Rattue