Long-Time Progression-Free Survival In Relapsed, Refractory Multiple Myeloma With The Oral Ixazomib-Lenalidomide-Dexamethasone Regime

Introduction: Despite great advances in therapy, multiple myeloma is still a largely incurable disease, therefore the importance of salvage therapies is paramount. The first oral proteasome inhibitor ixazomib in combination with lenalidomide-dexamethasone is a tolerable, orally administered regime, which has become available for Hungarian relapsed, refractory multiple myeloma patients from April 2015 in the Named Patient Program. Objective: Our goal was to investigate the long-time progression-free surviving patient population treated with the ixazomib-lenalidomide-dexamethasone triplet. Method: We retrospectively studied a total of 80 patients from 7 centers who received the triplet combination. Survival analyses were performed. Results: Two-third of the patients responded: the overall response rate was 63.75%. 14 patients (17.5%) did not respond/had stable disease and 15 patients (18.75%) outright progressed upon therapy. Although progression-free survival was only 10.6 months for the entire patient cohort, the disease in a subgroup of 16 patients did not progress within two years. In fact, 11 of them were still in sustained remission after 3 years of therapy. Our goal was to analyze the characteristics of this subgroup. Discussion: The idea of long-term therapy of multiple myeloma is gaining widespread acceptance. Therefore it is important to know which patients may benefit the most from certain therapies. Among these 16 long-term responder patients, reciprocal translocation of the immunoglobulin heavy chain seemed to lack an adverse impact on progression-free survival; comparable to trisomies, both curves had a progression-free plateau. The International Staging System (ISS) score at the start of therapy did not predict long-term survivorship. Most of the side effects in this subgroup were mild, manageable, none led to therapy discontinuation. Conclusion: Ixazomib-lenalidomide-dexamethasone was confirmed to be an effective and safe combination for relapsed, refractory multiple myeloma, and one-sixth of the treated patients were able to receive it for several years, effectively. This fully oral therapeutic option is at its best during the present COVID-19 pandemic.