Retrospective study of treatment patterns and outcomes post-lenalidomide for multiple myeloma in Canada.

Lenalidomide is an important component of initial therapy in newly diagnosed multiple myeloma, either as maintenance therapy post-autologous stem cell transplantation (ASCT) or as first-line therapy with dexamethasone for patients' ineligible for ASCT (non-ASCT). This retrospective study investigated treatment patterns and outcomes for ASCT-eligible and -ineligible patients who relapsed after lenalidomide as part of first-line therapy, based on data from the Canadian Myeloma Research Group Database for patients treated between January 2007 and April 2019. Among 256 patients who progressed on lenalidomide maintenance therapy, 28.5% received further immunomodulatory derivative-based (IMiD-based) therapy (lenalidomide/pomalidomide) without a proteasome inhibitor (PI) (bortezomib/carfilzomib/ixazomib), 26.2% received PI-based therapy without an IMiD, 19.5% received both an IMiD plus PI, 13.5% received daratumumab-based regimens, and 12.1% underwent salvage ASCT. Median progression-free survival (PFS) was longest for daratumumab-based therapy (22.7 months) and salvage ASCT (23.4 months) and ranged from 6.6 to 7.3 months for the other treatments (P < .0001). Median overall survival (OS) was also longest for daratumumab and salvage ASCT. A total of 87 non-ASCT patients received subsequent therapy, with 66.7% receiving bortezomib-based therapy and 13.8% receiving other PI-based therapy. Median PFS was 15.4 and 24.8 months for bortezomib-based and other PI-based therapy, respectively (P = .404). During most of the study period, daratumumab was not funded; in this setting, switching to a different therapeutic class following relapse on lenalidomide produced the longest remissions for non-ASCT patients. Further prospective studies are warranted to determine optimum treatment following relapse on lenalidomide, especially in the light of increased access to daratumumab.

Weekly carfilzomib plus cyclophosphamide and dexamethasone in the treatment of relapsed/refractory multiple myeloma: Final results from the MCRN-003/MYX.1 single arm phase II trial.

The MCRN-003/CCTGMYX.1 is a single arm phase II trial of weekly carfilzomib, cyclophosphamide and dexamethasone (wKCd), exploring a convenient immunomodulator (IMiD)-free regimen in relapsed myeloma. Weekly carfilzomib (20/70 mg/m2 ), dexamethasone 40 mg and cyclophosphamide 300 mg/m2 was delivered over 28-day cycles. The primary endpoint was overall response after four cycles. Secondary endpoints included toxicity, response depth, PFS and OS. Exploratory endpoints included the impact of cytogenetics, prior therapy exposure and serum free light chain (sFLC) escape; 76 patients were accrued. The ORR was 85% (68% ≥very good partial response [VGPR] and 29% ≥complete response [CR]). The median OS and PFS were 27 and 17 months respectively. High-risk cytogenetics conferred a worse ORR (75% vs. 97%, p = .013) and median OS (18 months vs. NR, p = .002) with a trend toward a worse median PFS (14 vs. 22 months, p = .06). Prior proteasome inhibitor (PI) or lenalidomide did not influence OS or PFS. The sFLC was noted in 15% of patients with a median PFS of 17 months when included as a progression event. The most common ≥ grade 3 non-hematologic adverse events were infectious (40%), vascular (17%) and cardiac (15%). The wKCD is a safe and effective regimen in relapse, especially for patients ineligible for lenalidomide-based therapies.

Drug-induced Thrombotic Microangiopathy with Concurrent Proteasome Inhibitor Use in the Treatment of Multiple Myeloma: A Case Series and Review of the Literature.

Thrombotic microangiopathy (TMA) is a life-threatening clinical syndrome characterized by hemolytic anemia, thrombocytopenia, and microvascular thrombosis, resulting in ischemia and organ damage. Multiple myeloma (MM) is a neoplasm arising from clonal plasma cells within the bone marrow. The treatment frequently includes multi-agent immunochemotherapy, often with the use of proteasome inhibitors (PIs) such as bortezomib, carfilzomib, or ixazomib. There are increasing reports of TMA in association with PI exposure. This review summarizes the epidemiology, pathogenesis, and diagnosis of PI-related drug-induced TMA. We will outline the definition and diagnosis of TMA and explore an important cause of hemolysis in patients with MM: drug-induced TMA after PI exposure, an increasingly recognized therapeutic complication. This will be emphasized through the description of 3 novel cases of TMA. These illustrative cases occurred after treatment with high-dose weekly carfilzomib, cyclophosphamide, and dexamethasone as part of the MCRN003/MYX1 phase II clinical trial (NCT02597062) in relapsed MM.

An open-label, pharmacokinetic study of lenalidomide and dexamethasone therapy in previously untreated multiple myeloma (MM) patients with various degrees of renal impairment - validation of official dosing guidelines.

Lenalidomide is a backbone agent in the treatment of multiple myeloma, but dose adjustment is required for those with renal impairment (RI). We evaluated the pharmacokinetics (PK) and safety of lenalidomide and dexamethasone as frontline pre-transplant induction, with doses adjusted at start of each cycle based on creatinine clearance, as per the official dosing guidelines. After 4 cycles, PK studies showed that patients with moderate RI (30 ≤ CrCl < 60 mL/min) receiving 10 mg dosing may be under-dosed and those with severe RI (CrCl <30ml/min) appeared appropriately dosed initially, but sustained significant decreases in maximum serum concentration (Cmax) after repeated dosing, due to rapid clinical improvement and enhanced drug clearance. PK drug monitoring during cycle 1 may facilitate appropriate and timely dose adjustments. Adverse events rates did not vary based on severity of RI. No patient discontinued lenalidomide for toxicity. This supports the feasibility and safety of frontline lenalidomide in transplant-eligible patients with RI.

Addition of Cyclophosphamide "On Demand" to Lenalidomide and Corticosteroids in Patients With Relapsed/Refractory Multiple Myeloma-A Retrospective Review of a Single-center Experience.

INTRODUCTION: The combination of lenalidomide and dexamethasone (Len-Dex) is an established regimen for patients with relapsed or refractory myeloma. To prolong the benefit of this effective regimen, the Myeloma Program at Princess Margaret Cancer Centre has routinely added a third agent, oral cyclophosphamide (Cy) given weekly, to Len-Dex at disease progression. PATIENTS AND METHODS: In the present report, we describe the cases of 53 patients who had received Len-Dex-Cy for a minimum of 4 weeks from January 2007 to December 2014 after progression with Len-Dex alone. The dose of added Cy ranged from 250 to 500 mg weekly. The median number of previous regimens, including Len-Dex, was 2 (range, 2-4); 80% of patients had undergone previous autologous stem cell transplantation. RESULTS: The overall rate of response equal to or greater than a partial response was 34%, and clinical benefit (stable disease or better) was observed in 87% of the patients. The median duration of Len-Dex-Cy therapy was 6.9 months (range, 0.9-55.1 months). The median progression-free survival was 6.1 months (range, 4.2-8.1 months) from the addition of Cy and 24.1 months (range, 15.9-32.0 months) from start of Len-Dex. CONCLUSION: The addition of Cy for patients with myeloma developing progression with Len-Dex was an inexpensive option with manageable toxicity that resulted in a clinically meaningful extension of disease control.

Final outcomes of escalated melphalan 280 mg/m2 with amifostine cytoprotection followed autologous hematopoietic stem cell transplantation for multiple myeloma: high CR and VGPR rates do not translate into improved survival.

The most common preparative regimen for autologous transplantation (ASCT) in myeloma (MM) consists of melphalan 200 mg/m2 (MEL 200). Higher doses of melphalan 220-260 mg/m2, although relatively well tolerated, have not shown significant improvement in clinical outcomes. Several approaches have been pursued in the past to improve CR rates, including poly-chemotherapy preparative regimens, tandem ASCT, consolidation, and/or maintenance therapy. Since there is a steep dose-response effect for intravenous melphalan, we evaluated an alternative single ASCT strategy using higher-dose melphalan at 280 mg/m2 (MEL 280) with amifostine as a cytoprotectant as the maximum tolerated dose determined in an earlier phase I dose escalation trial. We report the final long-term outcomes of MM patients who underwent conditioning with MEL 280 with amifostine cytoprotection followed by ASCT. Although the complete response rate was quite high in the era pre-dating the routine use of novel therapies (proteasome inhibitors, immunomodulatory agents) (49%), the progression-free survival was a disappointing 22 months. The implications of this dichotomy between the excellent depth of ASCT response and progression-free survival are discussed.

Current Review on High-Risk Multiple Myeloma.

PURPOSE OF REVIEW: New risk stratification systems and treatment strategies have been introduced in recent years. We aim to provide an overview of these recent changes and summarise these data in a concise article that would be useful for clinicians. RECENT FINDINGS: Apart from clinical stage, disease genetics are now recognised as important prognostic risk factors, and various new cytogenetic changes with negative prognostic impact have been identified. New technologies such as minimal residual disease detection are also playing an important role in prognostic assessment. Recent introduction of combination therapy with proteasome inhibitors and immunomodulatory drugs is showing promising results in high-risk patients and may partially abrogate the negative impact associated with some of the adverse risk factors. Recent advance has improved our understanding of high-risk multiple myeloma, and new therapeutic agents are now coming through the pipeline for this patient group with once dismal outcome.

Secondary primary malignancies during the lenalidomide-dexamethasone regimen in relapsed/refractory multiple myeloma patients.

Lenalidomide in combination with dexamethasone (Len-dex) represents a highly effective treatment in relapsed/refractory multiple myeloma (RRMM) patients. However, an increased risk of secondary primary malignancies (SPMs), including myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML) has been described in patients receiving lenalidomide. In order to assess the incidence and features of this complication, we reviewed 195 patients with RRMM treated with Len-dex at our institution. The median follow-up time from diagnosis of MM was 73 months (10-234 months) and from initiation of Len-dex was 19 months (1-104 months). The median duration of Len-dex for all patients was 7.8 months (range 1-90 months). The incidence rate (IR) for all SPMs from start of Len-dex was 2.37 per 100 patient-years, which reflected an IR of 1.29 for MDS/AML and 1.08 for nonhematologic malignancies (NHM). MDS was the most common SPM noted. The cumulative IR of SPM at 5 years was 1.54% from the time of MM diagnosis and 5.24% from starting Len-dex. Multivariable cumulative incidence of SPM analysis identified older age (P = 0.005) and prior number of regimens (P = 0.026) as adverse risk factors. We found more concomitant G-CSF use (P = 0.029) in patients with MDS/AML, however, causal association is not clear. The progression-free survival after Len-dex was the longest for patients in MDS/AML group, and the 5-year overall survival did not differ among groups. Although the rate of SPM was relatively low with Len-dex, concomitant G-CSF should be used judiciously and patients receiving this regimen should be observed for the development of this complication.

Cyclophosphamide and Bortezomib With Prednisone or Dexamethasone for the Treatment of Relapsed and Refractory Multiple Myeloma.

INTRODUCTION: Cyclophosphamide, bortezomib, and prednisone (CyBorP) is a highly effective, well-tolerated regimen in relapsed/refractory multiple myeloma. CyBorP, originally developed at our center to include weekly bortezomib (Bor) and alternate-day prednisone (P), was recently modified so that weekly dexamethasone (D) replaced prednisone. PATIENTS AND METHODS: To assess the effectiveness and tolerability of CyBorP/D in real-world practice, we identified 96 relapsed/refractory patients who received ≥ 1 28-day cycle of CyBorP/D, consisting of cyclophosphamide 300 mg/m(2) (days 1, 8, 15, and 22), Bor 1.0 to 1.5 mg/m(2) (days 1, 8, and 15), and either P 50 to 100 mg on alternate days or D 20 to 40 mg weekly between 2007 and 2013. RESULTS: Sixty-six (69%) patients achieved ≥ partial response: 16 with clinical complete response and 25 with very good partial response; 22 others had stable disease. Progression-free and overall survival for all patients were 16.2 months (95% confidence interval [CI], 7.7-20.1 months) and 26.3 months (95% CI, 21.6-81.2 months), respectively. Although 26 patients had prior Bor exposure, there was no difference in progression-free or overall survival versus Bor-naive patients. CONCLUSION: Toxicities with CyBorP/D were generally mild and manageable. New onset peripheral neuropathy was seen in 13 cases; 9 of 26 patients with pre-existing peripheral neuropathy developed worsening symptoms. No second primary malignancies were observed.

Management of multiple myeloma: the impact of ixazomib's approval in Canada.

Donna E Reece speaks to Laura Dormer, Commissioning Editor: Dr Donna E Reece is a Professor of Medicine and Director of the Program for Multiple Myeloma and Related Diseases in the Department of Medical Oncology and Hematology at Princess Margaret Hospital/University of Toronto. She earned a Bachelor of Arts degree at the University of Texas, Austin, and graduated as valedictorian with a medical degree from Baylor College of Medicine, Houston, Texas. She completed an internship in Internal Medicine at the University of Colorado Affiliated Hospitals, a residency and Chief Residency in Internal Medicine at Jewish Hospital, St Louis, and a Fellowship in Hematology/Oncology at Barnes Hospital, Washington University, St Louis, Missouri. She was a fellow and later a leukemia/stem cell transplant staff physician at Vancouver General Hospital/University of British Columbia for over 10 years. She then served as Director of the Outpatient Leukemia/Stem Cell Transplant Program, and later interim director, of the Blood and Marrow Transplant Program of the Markey Cancer Center at the University of Kentucky, Lexington, Kentucky until her appointment to Princess Margaret Hospital in Toronto in 2001. Dr Reece received the David and Molly Bloom Chair in Myeloma Research in 2009. She is currently the co-chair of the Multiple Myeloma Clinical Trials Group of the National Cancer Institute of Canada, member of the Scientific Advisory Board of the International Myeloma Foundation, and member of the Project Review Committee of the MMRC (Multiple Myeloma Research Consortium). She is also the Chief Medical Officer of the Myeloma Canada Research Network and serves on the board of directors of Myeloma Canada. Her career focus has been in the areas of hematopoietic stem cell transplantation, lymphoid malignancies and plasma cell dyscrasias. She has published numerous articles in these areas.

Elotuzumab in combination with lenalidomide and dexamethasone in patients with relapsed multiple myeloma: final phase 2 results from the randomised, open-label, phase 1b-2 dose-escalation study.

BACKGROUND: Elotuzumab, an immunostimulatory monoclonal antibody targeting signalling lymphocytic activation molecule (SLAM) family member 7 (SLAMF7), selectively kills SLAMF7-expressing myeloma cells through direct activation and engagement of the innate immune system, and thus might have clinical benefit in the treatment of myeloma. In phase 1 of this phase 1b-2 study, 82% of patients with relapsed multiple myeloma who were given elotuzumab plus lenalidomide and dexamethasone achieved an overall response. Here we report the final phase 2 results. METHODS: We did this randomised, multicentre, open-label, dose-escalation study (1703) at 17 hospitals in the USA, Canada, France, and Germany. Patients aged at least 18 years with confirmed, relapsed multiple myeloma, Eastern Cooperative Oncology Group performance status 0-2, and one to three previous therapies but no previous lenalidomide were eligible for phase 2. We randomly assigned patients (1:1) to either 10 mg/kg or 20 mg/kg intravenous elotuzumab plus oral lenalidomide (25 mg) and dexamethasone (40 mg). We stratified patients on the basis of the number of previous therapies (one versus two or three), and status of previous treatment with immunomodulatory drugs (yes or no), and used permuted block randomisation with a block size of four. Treatment was given in 28-day cycles until disease progression or unacceptable toxic effects occurred (elotuzumab was given on days 1, 8, 15, and 22 for cycles 1 to 2 and days 1 and 15 for subsequent cycles; lenalidomide was given on days 1-21 and dexamethasone once per week). The primary endpoint was the proportion of patients who achieved an objective response according to International Myeloma Working Group criteria. Primary analyses were done in the intention-to-treat population, and safety was analysed in all patients who received at least one dose of study drugs. This study is registered with ClinicalTrials.gov, number NCT00742560. FINDINGS: Between Jan 4, 2010, and Dec 21, 2010, we recruited and randomly assigned 73 patients to elotuzumab (36 to 10 mg/kg, 37 to 20 mg/kg). At data cutoff (Jan 16, 2014), 13 patients remained on treatment (six on 10 mg/kg, seven on 20 mg/kg). 61 (84%) patients achieved an objective response (33 [92%] with 10 mg/kg, 28 [76%] with 20 mg/kg); 31 (42%) a very good partial response (17 [47%] with 10 mg/kg, 14 [38%] with 20 mg/kg); and 20 (27%) a partial response (10 [28%] with 10 mg/kg, 10 [27%] with 20 mg/kg). The most common treatment-emergent adverse events of any grade were diarrhoea (48 [66%]), muscle spasms (45 [62%]), and fatigue (41 [56%]). 57 (78%) patients had grade 3-4 events, the most common of which were lymphopenia (15 [21%]) and neutropenia (14 [19%]). Three deaths occurred, none related to the study drugs. INTERPRETATION: Elotuzumab combined with lenalidomide and dexamethasone in patients with relapsed multiple myeloma showed acceptable safety and efficacy that seems better than that previously noted with lenalidomide and dexamethasone only. Phase 3 trials are in progress. FUNDING: Bristol-Myers Squibb, AbbVie Biotherapeutics.

The risk of secondary primary malignancies after therapy for multiple myeloma.

The development of a secondary primary malignancy (SPM) has become an important issue in myeloma management, given the remarkable improvement in survival afforded by the introduction of novel agents. Treatment with immunomodulatory derivatives, specifically lenalidomide, has recently been identified as a potential risk factor for SPM in several studies, especially in the maintenance setting. This study reviews potential mechanisms for development of SPM, incidence of SPM with different treatment regimens, risk factors associated with SPM and features of SPM after myeloma therapy. The incidence of SPM is discussed in the context of different settings in which lenalidomide is used during the course of the disease. No clear evidence indicates that lenalidomide alone is associated with SPM in the absence of other risk factors. Routine cancer surveillance, lifestyle modification to avoid cancer risk factors and prompt evaluation if new symptoms occur should be emphasized to patients who are on continuous myeloma therapy.

Absolute lymphocyte count as predictor of overall survival for patients with multiple myeloma treated with single autologous stem cell transplant.

Post-autologous stem cell transplant (ASCT) studies have demonstrated that absolute lymphocyte count (ALC) recovery is associated with prolonged survival in some hematological malignancies. To assess whether ALC recovery has prognostic significance in patients with multiple myeloma (MM) undergoing single ASCT, we conducted a retrospective analysis of ALC at different time-points in patients with MM. In total 769 consecutive patients who underwent single ASCT from January 2000 to December 2007 were evaluated. An ALC of ≥ 1400 cells/µL at day 0, day 15 and day 90 significantly correlated with a better overall survival (OS) (median OS of 111, 90.7 and 84 months vs. 74, 70.5 and 65 months, respectively, p < 0.001 for all time-points). Multivariate analysis showed that ALC is an independent prognostic factor for OS after ASCT. In conclusion, ALC is a surrogate marker of the host immune system that correlates with better survival in patients with MM undergoing single ASCT. Immunomodulatory drugs, vaccination strategies and cellular therapies in MM should be investigated.

Phase I-II trial of oral cyclophosphamide, prednisone and lenalidomide for the treatment of patients with relapsed and refractory multiple myeloma.

This single institution, open label Phase I-II dose escalation trial evaluated the safety and efficacy of the combination of lenalidomide (Revlimid®), cyclophosphamide and prednisone (CPR) in patients with relapsed/refractory multiple myeloma. The maximal administered dose of CPR consisted of cyclophosphamide 300 mg/m(2) on day 1, 8, and 15, lenalidomide 25 mg on d 1-21 and prednisone 100 mg every other day in a 28-d cycle. Between November 2007 and June 2009, 32 patients were entered in cohorts of three at three dose levels. The median age was 64 years, 59% were male, with a median two prior regimens. Responding patients could stay on treatment until progression. The full-dose CPR regimen produced no dose-limiting toxicity and was delivered for a median of 16 months (3·5-65 months) with acceptable safety and tolerance. The overall response rate (≥ partial response) was 94% at a median follow up of 28 months. The median progression-free survival was 16·1 months [95% confidence interval (CI); 10·9-22·5 months], while the median overall survival was 27·6 months (95% CI; 16·8-36·6 months). Only the beta-2 microglobulin level at protocol entry correlated with a better survival (P = 0·047). These observations compare favourably with other 2- and 3- drug combinations for relapsed/refractory myeloma, and suggest that CPR should be evaluated further in the setting of relapsed/refractory disease, or in newly diagnosed patients.

Intermittent granulocyte colony-stimulating factor for neutropenia management in patients with relapsed or refractory multiple myeloma treated with lenalidomide plus dexamethasone.

Neutropenia is a major dose-limiting toxicity associated with lenalidomide in relapsed/refractory multiple myeloma (MM). The optimal dosing schedule of granulocyte colony-stimulating factor (G-CSF) is unclear. We developed an intermittent G-CSF schedule (4-6 doses per cycle) initiated upon onset of grade 3-4 neutropenia. Of 216 patients with relapsed/refractory MM treated at our center with lenalidomide/dexamethasone on an Expanded Access Program, there was a high incidence of grade 3-4 neutropenia (61%) and grade 3-4 infections (37%). Despite intermittent G-CSF use in 117 patients, recurrent grade 3-4 neutropenia was common (59%), and dose reductions were required in 40% of G-CSF recipients, most due to thrombocytopenia. G-CSF recipients had a longer duration on therapy and achieved a higher rate and depth of response. Intermittent G-CSF may be an effective approach for lenalidomide dose-preservation, which may lead to improved outcomes, although it does not prevent infections or thrombocytopenia-related dose limitations.