Results of a recent Italian study suggest that a combination of Velcade and dexamethasone is a safe and effective form of maintenance therapy for relapsed/refractory multiple myeloma patients who responded to Velcade-containing rescue regimens.

“Our study showed that maintenance therapy with Velcade in relapsed / refractory multiple myeloma patients may improve the progression-free survival and overall survival of patients with a low grade of toxicity,” Dr. Giulia Benevolo, lead author of the study, told The Myeloma Beacon.

“[However], this is a Phase 2 trial, and the results must be confirmed in randomized trials,” Dr. Benevolo added.

Over the past decade, novel drugs such as Velcade (bortezomib), thalidomide (Thalomid), and Revlimid (lenalidomide) have increased the overall survival of multiple myeloma patients, but most patients eventually relapse and require rescue therapies to control or delay disease progression.

Patients who respond to rescue therapy often subsequently receive maintenance therapy with the aim of prolonging remission.

All three novel agents have been investigated and used as maintenance therapy. Results of past studies suggest that Revlimid maintenance increases the survival and time to disease progression for myeloma patients following stem cell transplantation. However, these studies have also raised concerns that Revlimid maintenance may increase the risk for developing secondary cancers (see related Beacon news).

Prior studies have also shown that thalidomide maintenance therapy improves overall survival, but thalidomide has not been widely adopted as maintenance therapy because of concerns about its side effects.

Results of a recent Phase 3 clinical trial involving newly diagnosed multiple myeloma patients indicate that more patients achieve a complete response with Velcade maintenance than thalidomide maintenance following Velcade-containing initial therapies and autologous stem cell transplantation.

Dr. Benevolo and her colleagues sought to assess whether Velcade in combination with dexamethasone (Decadron) is a safe and effective form of maintenance therapy in relapsed/refractory multiple myeloma patients who previously responded to Velcade-containing rescue therapies.

The study included 49 relapsed/refractory multiple myeloma patients with a median age of 71 years. The patients had received a median of two prior therapy regimens.

All patients had responded to Velcade-containing rescue therapies after having relapsed or been refractory to prior treatment. Patients who achieved a complete response after Velcade-containing rescue therapies were excluded because their disease was not measurable.

All patients received 1.3 mg/m² of Velcade on days 1 and 15 and 20 mg of oral dexamethasone on days 1-2 and 15-16 of successive 28-day cycles until relapse.

After a follow-up of 25 months, the researchers found that Velcade maintenance improved the quality of response after rescue therapy to a complete response in 8 percent of patients and to a very good partial response in 6 percent of patients.

The overall response rate was 35 percent, and the median time to progression was 17 months.

After one year, 79 percent of patients were still alive and 61 percent of patients had not progressed.

According to the researchers, side effects were generally mild.  The most common side effect was peripheral neuropathy, or treatable pain and tingling sensations in the extremities, which was experienced by 31 percent of the patients.  Other side effects included fatigue (16 percent), constipation or diarrhea (6 percent), shingles (4 percent), and pneumonia (2 percent).  Six percent of patients experienced peripheral neuropathy that was severe enough to require a reduction in their Velcade dose.

None of the patients experienced severe pain and tingling sensations or blood-related side effects, and none of the patients died from side effects.

For more information, please see the full article in the journal Cancer (abstract).