Phase II study of carfilzomib and dexamethasone therapy for newly diagnosed multiple myeloma

Cardiovascular Toxicity of Proteasome Inhibitors in Multiple Myeloma Therapy

The treatment for multiple myeloma has advanced significantly over the past few decades. Proteasome inhibitors have become the cornerstone of the treatment of multiple myeloma. However, proteasome inhibitors have shown cardiovascular complications such as hypertension, pulmonary hypertension, heart failure, arrhythmias, ischaemic heart disease and thromboembolism. Detection, monitoring and management of proteasome inhibitor-related cardiovascular toxicity are essential to improve clinical outcomes for patients. Proposed mechanisms of proteasome inhibitor-related cardiovascular toxicity are apoptosis, prolonged inhibition of the ubiquitin-proteasome system, accumulation of improperly folded proteins within cardiomyocytes and higher protein phosphatase 2A activity. To better understand the mechanisms underlying cardiotoxicity, further in vitro and in vivo experiments are required to investigate these hypotheses. Combined use of metformin or angiotensin II receptor blockers with the proteasome inhibitor, carfilzomib, showed an emerging role as a prophylactic therapy because they can preserve heart function in multiple myeloma patients. Metformin is expected to be an effective therapeutic intervention for the management of carfilzomib-induced cardiotoxicity. There has been evidence that three compounds, apremilast, rutin, and dexrazoxane, can reverse carfilzomib-induced cardiotoxicity in rats. The future transition from animal experiments to clinical trials is worth waiting for.

Carfilzomib and dexamethasone induction with lenalidomide, clarithromycin and dexamethasone consolidation and lenalidomide maintenance for newly diagnosed multiple myeloma

Combination treatment regimens including a proteasome inhibitor (PI), an immunomodulatory agent (IMiD) and a corticosteroid are standards of care for initial treatment of multiple myeloma (MM). We aimed to evaluate if a sequential treatment program using PI induction followed by IMiD based consolidation and maintenance could achieve similar outcomes with reduced toxicities. This phase 2 study was designed to assess the safety and efficacy of the Car-BiRd regimen: carfilzomib and dexamethasone (Kd) induction until maximum response, followed by lenalidomide, clarithromycin and dexamethasone (BiRd) consolidation until next maximum response, then lenalidomide maintenance in patients with newly diagnosed MM. Seventy-two patients, including both transplant eligible and ineligible patients, were enrolled and evaluated for response. The overall response rate to the Car-BiRd regimen was 94% with 83% of patients achieving a ≥ VGPR and 35% achieving a CR/sCR. The rate of CR/sCR increased from 7% with Kd induction to 21% with BiRd consolidation and 35% with lenalidomide maintenance. These results did not meet the study's target endpoint of a CR rate of 55%. The median PFS using this deferred transplant approach was 37.3 months (95% CI 27.9, 52.7) and median OS was not reached with a median follow-up of 60 months. Toxicities were primarily low grade and manageable. Hematologic toxicities were lower than those expected with a combination PI/IMiD protocol. The sequential Car-BiRd regimen is an effective and safe approach for the upfront treatment of MM including patients unfit for transplant.

Efficacy and Toxicity Profile of Carfilzomib-Based Regimens for Treatment of Newly Diagnosed Multiple Myeloma: A Systematic Review

Carfilzomib (CFZ) is a proteasome inhibitor currently approved for the treatment of relapsed and refractory multiple myeloma (RRMM). Multiple trials are ongoing to evaluate its efficacy and safety in newly diagnosed multiple myeloma (NDMM). The use of CFZ-based two- or three-drug combination regimens as induction for the management of NDMM is an emerging approach. CFZ-based regimens include combinations of immunomodulators, alkylating agents, and monoclonal antibodies along with dexamethasone. In this review, we assess the efficacy and toxicity of CFZ-based regimens in NDMM. We reviewed a total of 27 studies (n=4538 patients) with overall response rates (ORR) ranging between 80% and 100%. Studies evaluating the combination of CFZ with daratumumab reported an ORR of approximately 100%. Achievement of minimal residual disease (MRD) negativity, measured by multi-parameter flow cytometry (MPFC), ranged between 60% and 95% in 4 (n=251) out of 6 studies that measured MRD-negativity. The interim results of the ENDURANCE trial failed to show superior efficacy and progression-free survival (PFS) of carfilzomib-lenalidomide when compared to bortezomib–lenalidomide combination, albeit with a lower incidence of neuropathy. Hematological toxicity was the most common adverse event observed with these regimens, and the most common non-hematological adverse events were related to cardiovascular and electrolyte disturbances. We need to further evaluate the role of CFZ in NDMM by conducting more Phase III trials with different combinations.