How to treat patients with relapsed/refractory multiple myeloma: evidence-based information and opinions

Bortezomib retreatment for relapsed and refractory multiple myeloma in real-world clinical practice

AIMS

Studies have shown that bortezomib retreatment is effective in relapsed/refractory multiple myeloma (MM). The observational, prospective electronic VELCADE® OBservational Study (eVOBS) study assessed bortezomib-based therapies for patients with MM in everyday practice. Here, we report on those patients receiving retreatment with bortezomib.

METHODS

Consenting adults scheduled to receive bortezomib for MM were enrolled at 162 sites across Europe, Canada, Brazil, Russia, and Turkey between 2006 and 2010. Retrospective data on prior therapies and prospective observational data after bortezomib initiation were captured electronically at baseline, after every bortezomib cycle, and every 12 weeks after discontinuation or progression. Investigator-assessed responses and adverse events (AEs) were evaluated.

RESULTS

Ninety-six of 873 patients enrolled to eVOBS received bortezomib as first retreatment for progressive disease during the prospective observation period. Median age was 62 years, 53% were male, and median number of prior therapies at retreatment was 4. Overall, 41% of patients initiated bortezomib retreatment in combination with dexamethasone, 16% in combination with lenalidomide, and 21% received monotherapy. Rate of partial response or better (≥PR) was 75% at initial bortezomib therapy, including 44% complete response (CR)/near CR (nCR); at retreatment, ≥PR rate was 46%, including 15% CR/nCR. Median progression-free survival was 11.4 months (95% confidence interval [CI]: 9.1-12.7) from start of initial bortezomib treatment and 6.4 months (95% CI: 4.4-7.2) from start of retreatment. Median overall survival from start of retreatment was 17.6 months (95% CI: 14.4-23.5). Of the 96 patients retreated with bortezomib, 77% reported an AE. Peripheral neuropathy during bortezomib retreatment occurred in 49% of patients, including 10% grade 3/4.

CONCLUSION

These data suggest that retreatment with bortezomib is a feasible option for patients with relapsed/refractory MM.

Efficacy and safety of salvage therapy using Carfilzomib for relapsed or refractory multiple myeloma patients: a multicentre retrospective observational study

Carfilzomib has been established in previous years as a treatment for patients with relapsed and/or refractory multiple myeloma (RR-MM). A retrospective multicentre study to evaluate the clinical use of carfilzomib for RR-MM outside of a clinical trial setting was conducted by our group. One hundred and thirty-five patients were included. All patients had been previously exposed to bortezomib and 93% had also been treated with lenalidomide. The vast majority of patients received carfilzomib as part of a two- or three-drug combination. The overall response rate was 47·2%. Multivariate analysis revealed bortezomib resistance, lenalidomide resistance and albumin <35 g/l to negatively impact the likelihood of achieving response. The median duration of response was 8·4 months, and was significantly higher in patients receiving three-drug combination and patients presenting without extramedullary disease. The median progression-free survival and overall survival for the entire cohort was 4·9 months (95% confidence interval [CI] 3·8-6·4) and 12·2 months (95% CI 9-not reached), respectively. Toxicity was manageable, although treatment-related death was seen in 5% of patients. In the setting of progressive multiple myeloma, carfilzomib in a combination regimens yields effective results with a manageable toxicity.

New approaches to management of multiple myeloma

Multiple myeloma is still an incurable disease with pattern of regression and remission followed by multiple relapses raising from the residual myeloma cells surviving even in the patients who achieve complete clinical response to treatment. New antimyeloma drugs such as thalidomide, lenalidomide, and bortezomib have dramatically changed treatment paradigm leading to both tumor reduction and tumor suppression. Much progress has been made, but still many unsolved questions remain. In the mode of sequencing treatment for patients with multiple myeloma, we are still using old drugs such as the alkylating agent melphalan, which continues to play a central role in the transplantation setting. Newer drugs are now emerging and are being tested: monoclonal antibodies, histone deacetylase (romidespsin), MLN9708 (ixazomib) a new oral proteasome inhibitor, carfilzomib, signal transduction modulator perifosine. Many advances have been made, but there is still a long way to go.

European perspective on multiple myeloma treatment strategies: update following recent congresses

The management of multiple myeloma has undergone profound changes over the recent past as a result of advances in our understanding of the disease biology as well as improvements in treatment and supportive care strategies. Notably, recent years have seen a surge in studies incorporating the novel agents thalidomide, bortezomib, and lenalidomide into treatment for different disease stages and across different patient groups. This article presents an update to a previous review of European treatment practices and is based on discussions during an expert meeting that was convened to review novel agent data published or presented at medical meetings until the end of 2011 and to assess their impact on treatment strategies.