Results of a recent study show that multiple myeloma patients who were initially treated with either thalidomide or Revlimid demonstrated strong responses to treatment with Revlimid and pomalidomide following relapse. In particular, researchers observed the highest response rates in patients who received treatment with pomalidomide.

Dr. Sumit Madan of Mayo Clinic in Rochester, Minnesota, presented the study results at the American Society of Hematology annual meeting in Orlando last month.

Research has previously shown that thalidomide (Thalomid) and Revlimid (lenalidomide), which belong to the same class of drugs called immunomodulatory agents, are highly active treatments for patients with newly diagnosed myeloma. They are commonly used as initial therapy prior to stem cell transplantation and may also be used as salvage therapy if the patients are unresponsive to treatment or experience relapse. In most cases, the salvage therapies consist of the same treatment drugs at an increased dosage or a combination treatment of the same and new drugs.

The developmental drug pomalidomide (Pomalyst) is a third compound in the same class of drugs that has shown promising results in relapsed/refractory myeloma patients (see related Beacon news).

According to the study authors, there is currently no data available indicating the efficacy of these compounds in relapsed patients who received thalidomide or Revlimid as initial therapy.

In order to obtain this information, Dr. Madan and his colleagues enrolled 410 patients with newly diagnosed myeloma. The median age of the patients at the time of enrollment was 60 years. All patients received initial treatment with thalidomide (58 percent) or Revlimid (42 percent). Both initial therapies also included dexamethasone (Decadron).

Following relapse, 183 patients received salvage therapy with thalidomide (22 percent), Revlimid (70 percent), or pomalidomide (8 percent). Among the patients in this study group, 118 (64 percent) had undergone autologous stem cell transplantation after the initial therapy.

Researchers found that 37 percent of patients responded to the salvage therapy.

In particular, they noted that response rates were highest when patients received salvage therapy with pomalidomide. Approximately 83 percent of patients first treated with Revlimid and then with pomalidomide responded to the salvage therapy. Likewise, 80 percent of patients first treated with thalidomide and then with pomalidomide responded to the salvage therapy.

Of the patients who received Revlimid as salvage therapy, those who were retreated with Revlimid showed higher response rates (52 percent) than those who had received thalidomide as initial therapy (46 percent).

However, patients who received thalidomide as the salvage therapy achieved the lowest response rates. Approximately 25 percent of patients who received initial treatment with Revlimid responded to salvage treatment with thalidomide. Of the patients who were retreated with thalidomide, 30 percent responded.

For more information, please refer to abstract 1964 at the American Society of Hematology meeting website.