2 Common Additions to Multiple Myeloma Therapy Don’t Offer Added Benefit, Study Says

The results of a new clinical trial suggest that two extension treatments that are frequently added to standard therapy care in patients with multiple myeloma do not improve patients’ progression-free survival compared to the current standard practice alone.

The results were presented at the 58^th American Society of Hematology Annual Meeting & Exposition (ASH 2016) Dec. 3-6 in San Diego.

Edward A. Stadtmauer, MD, of the Abramson Cancer Center at the University of Pennsylvania, presented the study, titled “Comparison of Autologous Hematopoietic Cell Transplant (autoHCT), Bortezomib, Lenalidomide (Len) and Dexamethasone (RVD) Consolidation with Len Maintenance (ACM), Tandem AutoHCT with Len Maintenance (TAM) and AutoHCT with Len Maintenance (AM) for up-Front Treatment of Patients with Multiple Myeloma (MM): Primary Results from the Randomized Phase III Trial of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN 0702 – StaMINA Trial).”

For those younger than 70 and who are physically fit, the standard therapy for multiple myeloma consists of:

• A first course of treatment combinations of proteasome inhibitors, thalidomide analogues, corticosteroids, and alkylating agents, in addition to high doses of the chemotherapy agent Alkeran (melphalan), to kill cancer cells;
• A stage where the patient’s own hematopoietic stem cells (autoHCT) are transplanted to help rebuild the immune system;
• Ongong treatment with Revlimid (lenalidomide) chemotherapy to prevent the cancer from returning.

The extension treatments that were analyzed in this study refer to the additions that some doctors have included to this traditional standard treatment course in the past 10 years, namely a) an additional three-drug course of chemotherapy after autoHCT, including dexamethasone and Velcade (bortezomib) in addition to Revlimid, or b) an additional second round of autoHCT.

Enrolling 758 patients spread through 54 centers – who were randomly assigned to either standard care, standard care plus additional chemotherapy, or standard care plus a second round of autoHCT – the study suggests that none of the additional treatments made a difference in terms of the study’s primary endpoint, to achieve 38-month survival without disease progression, as indicated by intent-to-treat.

Progression-free survival was observed in 52%, 57%, and 56% of patients in each of the three arms, respectively. Researchers will continue to track participants in another follow-up study to assess long-term trends and outcomes.

“These results are very important because they answer a question that has been ongoing and has not been compared head-to-head: ‘Does the addition of these interventions result in a true advantage for these patients?’” Stadtmauer said in a press release. “The conclusion of this study, so far, is that the other interventions are not superior to initial melphalan [Alkeran] therapy followed by a single autoHCT followed by lenalidomide [Revlimid] maintenance.”

The study’s Data and Safety Monitoring Board released these results before all the patients completed their follow-up period, but final analyses including secondary outcomes measures will be available after the completion of the 38 months of follow-up by all participants.

Secondary outcomes included measuring quality of life indicators, degree of disease response, and evidence of toxicity.

“Despite remarkable advances in the therapy and outlook for patients with multiple myeloma over the last decade, ultimately many patients will have their disease progress. So there’s always room for improvement,” Stadtmauer said.

“New therapies and interventions need to be actively investigated to see how much they further benefit the early treatment of patients with myeloma; I believe that the results of this study suggest it would be reasonable to compare any new treatments to the standard therapy of [Alkeran] followed by a single autoHCT followed by [Revlimid] maintenance.”

This is the largest randomized, controlled trial of post-transplant therapy for multiple myeloma ever conducted in the U.S.