Outcome of carfilzomib/pomalidomide-based regimens after daratumumab-based treatment in relapsed multiple myeloma: A Canadian Myeloma Research Group Database analysis.

INTRODUCTION: Although daratumumab-containing regimens improve multiple myeloma (MM) outcomes, recurrence is inevitable. METHODS AND OBJECTIVE: We performed a retrospective study using the Canadian Myeloma Research Group Database to benchmark the efficacy of carfilzomib- or pomalidomide-based therapies immediately following progression on daratumumab treatment. RESULTS: We identified 178 such patients; median number of prior lines of therapy was 3, 97% triple-class exposed, and 60% triple-class refractory. In our cohort, 75 received a subsequent carfilzomib-based therapy, 79 received a pomalidomide-based therapy, and 24 received a treatment with both immunomodulatory drug (IMiD) and proteasome inhibitor (PI) using carfilzomib and/or pomalidomide. The median progression-free survival (PFS) and overall survival (OS) for the entire cohort were 4.5 and 14.2 months, respectively. Carfilzomib-based therapy yielded a median PFS and OS of 4.5 and 10.2 months, respectively, compared to 5.2 and 21.7 months for pomalidomide-based therapy. Patients who received both IMiD and PI with carfilzomib and/or pomalidomide had a median PFS and OS of 4.1 and 14.5 months, respectively. CONCLUSION: Our observations demonstrate the poor outcome of MM patients when standard regimens based on carfilzomib and/or pomalidomide are utilized directly after daratumumab-based therapy given in the relapsed setting. Novel therapies, including immune therapies, are urgently needed to improve the outcomes of these daratumumab-exposed patients.

Outcomes of daratumumab in the treatment of multiple myeloma: A retrospective cohort study from the Canadian Myeloma Research Group Database.

Daratumumab (dara) has significantly altered the therapeutic landscape of multiple myeloma (MM), especially in the relapsed setting. This study aimed to evaluate the outcomes of dara-containing regimens in the Canadian real-world setting among relapsed and refractory MM available within the national Canadian Myeloma Research Group Database (CMRG-DB). A total of 583 MM patients who received dara-based therapy in second-line or later treatment were included. After a median follow-up of 17.5 months, the median progression-free survival (PFS) and overall survival (OS) for the entire cohort were 13.1 and 32.9 months, respectively. The median PFS and OS were 23.5 and 49.1 months in second-line treatment and decreased to 12.8 and 43.0 months in third-line and 7.0 and 20.5 months in fourth-line treatment respectively. Dara in monotherapy with or without corticosteroids after a median of four prior lines of therapy resulted in a median PFS of 3.9 months and a median OS of 17.1 months. The addition of bortezomib, lenalidomide or pomalidomide to dara resulted in an improved median PFS and OS of 8.3 and 26.2 months; 26.8 and 43.0 months; and 9.7 and 31.4 months respectively. These retrospective data from the CMRG-DB suggest that outcomes are superior when dara is used in combination and in earlier lines of treatment.

Kinetics of response to first- and second-line therapies in multiple myeloma: Assessment by both M-spikes and light chains.

OBJECTIVES: The prognostic value of kinetics of response to multiple myeloma (MM) therapy is controversial. We aimed to expand the knowledge on this topic by reviewing the kinetics of response to both first- and second-line MM therapy, utilizing a homogeneously treated cohort and analyzing separately both M-spike and light chain (LC) responses for each patient. METHODS: We reviewed all patients who received first-line cyclophosphamide, bortezomib and dexamethasone induction followed by autologous transplant with melphalan and lenalidomide maintenance in our center between 2007 and 2019. RESULTS: Analyzing 360 patients, we observed no correlation between response kinetics to first- versus second-line therapy at the individual patient level. Time to best response to first-line therapy was not a predictor of outcome; however, longer time to best response was highly predictive of a favorable outcome in the second-line setting, independent of other factors. Patients with IgA-MM cleared their M-spike faster than IgG-MM, probably reflecting different half-lives of these isotypes rather than disease biology, as the clearance of LC in both subtypes was similar. CONCLUSIONS: Analyzing both M-spike and LC responses in a homogenously treated cohort, we identified important insights regarding the prognostic value of kinetic patterns. Prospective analysis may shed more light on unsolved questions.

Real-world outcomes with bortezomib-containing regimens and lenalidomide plus dexamethasone for the treatment of transplant-ineligible multiple myeloma: a multi-institutional report from the Canadian Myeloma Research Group database.

Bortezomib-containing regimens (BCRs) represented standard, first-line therapy for transplant-ineligible multiple myeloma (TIMM) in Canada until the introduction of lenalidomide and low-dose dexamethasone (Ld). However, little comparative data exist to inform the selection of regimens. We assessed the outcomes for TIMM patients treated with cyclophosphamide, bortezomib and dexamethasone or prednisone (CyBorD/P), bortezomib, melphalan and prednisone (VMP), bortezomib and dexamethasone or prednisone (VD/P) and lenalidomide and low-dose dexamethasone (Ld) using the Canadian Myeloma Research Group database. Of 1156 TIMM patients evaluated, 82% received bortezomib combinations while 18% received Ld. Median progression-free survival (PFS) was 21·0, 21·1, 13·2 and 28·5 months (P = 0·0002) and median overall survival (OS) was 52·0, 63·6, 30·8 and 65·7 months (P < 0·0001) in the CyBorD/P, VMP, VD/P and Ld groups respectively. There was no significant difference in PFS and OS between the two triplet bortezomib regimens (VMP and CyBorD/P). Ld was associated with a longer PFS but not a significantly superior OS to date. Outcomes with the bortezomib-steroid doublet were inferior (VD/P). However, multivariable analysis identified features related to disease biology as the most important prognostic factors for PFS and OS. Such factors, as well as those affecting the physician's choice of regimen, are likely to influence the results observed with different regimens. This study demonstrated real-world outcomes in TIMM similar to those reported in clinical trials.

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.

The impact of lenalidomide maintenance on second-line chemotherapy in transplant eligible patients with multiple myeloma.

OBJECTIVES: To understand the impact of therapy sequencing on progression-free (PFS) and overall survival (OS) for the treatment of multiple myeloma (MM). The use of daily, low-dose, lenalidomide maintenance (LM) has raised concern for fostering resistance, preventing its use in the relapsed setting. METHODS: We conducted a retrospective analysis of survival outcomes from the Canadian Myeloma Research Group Database. Patients were grouped based on receipt of LM after autologous stem cell transplant and receipt of lenalidomide in second-line therapy, 575 patients were included. RESULTS: Patients treated with LM had statistically similar 2nd PFS when re-exposed to lenalidomide in second-line therapy compared to those receiving non-lenalidomide-containing regimens (10.2 vs 14.0 months, P =.53). This cohort also had the longest 2nd OS, 18 months longer than patients treated with LM who did not receive lenalidomide at relapse (55.3 vs 37 months, P =.004). Patients treated with LM also demonstrated deeper responses to second-line therapy than their non-LM counterparts. CONCLUSION: Our data suggest that patients progressing on LM who receive lenalidomide-containing therapy at first relapse have comparable 2nd PFS and better 2nd OS compared to non-lenalidomide-containing second-line regimens. Identification of patients mostly likely to benefit from further lenalidomide-containing therapy is paramount.

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.

Central nervous system involvement with multiple myeloma: long term survival can be achieved with radiation, intrathecal chemotherapy, and immunomodulatory agents.

Involvement of the central nervous system (CNS) in multiple myeloma (MM) is a rare complication, with reported survival of <6 months. This report describes 37 MM patients with leptomeningeal and/or parenchymal brain involvement treated at our institution and identifies factors associated with long-term survival. From January 1999 to December 2010, 37 patients with CNS MM were evaluated at our institution. Clinical characteristics, treatment and survival were retrospectively collected. CNS disease was present at MM diagnosis in 24% and at relapse in 76%. Plasma cell leukemia (40%) and skull plasmacytomas (65%) were common, suggesting haematological and contiguous spread. Intrathecal (IT) chemotherapy was used in 81%, cranial and/or spinal irradiation in 78%, and various systemic therapies [immunomodulatory agents (IMiDs) (51%), cisplatin-based (DPACE; cisplatin, doxorubicin, cyclophosphamide, etoposide) (27%), bortezomib (19%), alkylators (11%), dexamethasone alone (8%), auto-transplant (5%)]. Median survival from CNS disease was only 4·6 months [95% confidence interval (CI): 2·8-6·7]; however, nine patients had prolonged survival (median: 17·1 months, 95% CI: 13·2-67·4). In general, these long-term survivors were treated with radiotherapy, multi-dosing IT chemotherapy, and IMiD-containing therapy. CNS MM is a highly aggressive disease but in our experience, long-term survival can be achieved with the combination of multi-dosing IT chemotherapy, radiation and IMiD-based therapy.

Post Salvage Therapy Autologous Transplant for Relapsed Myeloma, Ongoing Relevance within Modern Treatment Paradigms?

BACKGROUND: Salvage transplant has been historically considered effective therapy for myeloma patients relapsing after first transplant, if they achieved adequate remission duration. However, the efficacy of novel agent combinations has called this paradigm into question. MATERIALS AND METHODS: We performed a retrospective analysis in a homogeneously treated cohort of 106 patients undergoing ASCT2 at our institution, all of whom received novel agent-based chemotherapy (immunomodulatory agent [IMiD] and/or proteasome inhibitor [PI]) for both induction and relapse. As an exploratory objective we assessed whether predictive thresholds of progression free survival post first transplant (ASCT1) for benefit post ASCT2 vary with use of IMiD maintenance post ASCT1. RESULTS: The overall response rate (ORR) was 98% post-ASCT2 and treatment-related mortality (TRM) was low at 1.8%. With a median follow-up of 26 months (range 0.5-85) from ASCT2, median overall survival (OS) is estimated at 80 months (95% CI: ≥ 49-months) and median progression-free survival after ASCT2 (PFS2) at 24 months (95% CI 19-39). PFS post first transplant (PFS1) at >/= 50 months was associated with improved OS. Predictors of PFS2 included PFS1 ≤42 months and progression on IMiD-based maintenance post- ASCT1. CONCLUSION: ASCT2 continues to offer acceptable outcomes for most patients treated within modern day treatment paradigms, with longer PFS after ASCT1 and IMiD non-refractory disease being associated with improved outcomes.

The Impact of CD34+ Cell Collection Yields for Autologous Transplant on Survival Outcomes in Multiple Myeloma.

INTRODUCTION: According to previous data, higher yields of stem-cells collected to support autologous transplantation may predict for improved outcomes. We aimed to assess the association between high stem-cells collection and survival outcomes in multiple myeloma (MM) MATERIALS AND METHODS: We reviewed all patients who underwent autologous transplantation for MM at our center over a 10-year period, and initially used a predefined threshold of 8 × 106/kg used in previous studies. RESULTS: Six hundred twenty-one patients were analyzed. Higher mobilization did not correlate with favorable outcomes post-transplant. The most efficient mobilizers, collecting ≥8 × 106/kg (n = 478) achieved a shorter median progression-free survival (PFS) of 24.1m versus 34.5m in patients collecting 4.5 to 8 × 106/kg (n = 129). A small group (n = 14) collecting ≤4.5 × 106/kg but minimum of 2 × 106/kg to support autologous transplantation exhibited the worst outcomes (median PFS 11.4m). Further analysis of potential confounders identified greater use of bortezomib induction in the lower mobilizers, however, sensitivity analysis in patients receiving bortezomib revealed similar results- worst outcomes to the most efficient mobilizers. CONCLUSION: Although bortezomib is not considered stem-cell toxic, it may be associated with lower stem cell collection yields. Bortezomib's efficacy at induction may partially explain the improved outcomes, however, other factors may be involved, and are discussed. We can conclude that with our large cohort and long follow-up, high stem-cell mobilization does not appear to predict for a long-term survival advantage.

Real-world data on lenalidomide dosing and outcomes in patients newly diagnosed with multiple myeloma: Results from the Canadian Myeloma Research Group Database.

Using the Canadian Myeloma Research Group Database, a retrospective study of 167 newly diagnosed, transplant-ineligible patients with multiple myeloma (MM) that received lenalidomide-dexamethasone as front-line treatment was conducted to understand the impact of lenalidomide dosing. Starting dose modifications were common, 42% of patients started on lenalidomide <25 mg with normal renal function. During treatment course, 35% of patients required further dose reduction. Dose reductions in the first year did not have an impact on progression free survival or overall survival. Further studies need to be conducted to understand the impact of dosing strategies of anti-MM agents in the real world.

Real-world results of autologous stem cell transplantation in newly diagnosed multiple myeloma: a report from the Canadian Myeloma Research Group database.

Autologous stem cell transplant (ASCT) remains an important option for eligible multiple myeloma (MM) patients as part of initial therapy. Using the Canadian Myeloma Research Group (CMRG) national database, we examined the details and outcomes of ASCT performed as first-line therapy in eligible Canadian MM patients between 2007 to 2021. We included 3821 patients with 72% receiving CyBorD induction and 2061 patients receiving maintenance, consisting of lenalidomide +/- steroids in 78.3%. The median PFS and OS for patients given a single ASCT were 35.4 and 126 months. Those receiving a second induction regimen had significantly inferior outcomes, although when maintenance was used, results were comparable regardless of the number of induction regimens administered (median PFS 55.3 vs 51.1 months [p = 0.11]; median OS 158.6 vs not yet reached [p = 0.13]). Consolidation patients had a longer median PFS (55.3 vs 34.4 months [p = 0.001]), but no significant gain in median OS (p = 0.065). Patients who received lenalidomide-based maintenance experienced a median PFS of 53.7 months and OS of 159 months. In the multivariable analysis, use of any type of maintenance therapy vs no maintenance was associated with a lower risk of progression (HR 0.52 (95% CI 0.47-0.57)) and death (HR 0.58 (95% CI 0.51-0.67)). This real-world study demonstrates that, overall, first-line treatment sequence in transplant-eligible patients produces a median OS of ≥10 years. It also highlights the contribution of post-ASCT maintenance, particularly lenalidomide given until progression.

Redefining attrition in multiple myeloma (MM): a Canadian Myeloma Research Group (CMRG) analysis.

While most patients diagnosed with multiple myeloma (MM) receive initial therapy, reported attrition rates are high. Understanding attrition rates and characteristics of patients not receiving subsequent therapy is useful for MM stakeholders. We performed an analysis of attrition rates in a large disease-specific database of patients with newly diagnosed MM who received at least one line of therapy between Jan 1/10-Dec 31/20. Attrition was defined as failure to receive a subsequent line of therapy despite progression of MM or due to death. A total of 5548 patients were identified, 3111 autologous stem cell transplant (ASCT) patients and 2437 non-ASCT. In the ASCT cohort, the attrition rate was 7% after line 1, 12% after line 2, and 23% after line 3. In non-ASCT patients, the attrition rate was 19% after line 1, 26% after line 2, and 40% after line 3. Death was the dominant contributor to attrition across all cohorts, with a minority of patients alive with progressive disease in the absence of further therapy at each line. Multivariable analysis identified older age, shorter time to progression, and inferior response as independent risk factors for attrition. Our data show that attrition rates increase with each line of therapy and are higher in non-ASCT patients but are appreciably lower than previously reported. This study supports a revision of the previous definition of attrition, demonstrating that most patients who do not receive subsequent therapy are either continuing their current therapy and/or are in remission off-treatment rather than being irreversibly lost to attrition.

Second autologous stem cell transplantation as salvage therapy for multiple myeloma: impact on progression-free and overall survival.

The role of a second autologous stem cell transplant (ASCT) as salvage therapy is unclear, particularly with the availability of novel agents to treat progressive multiple myeloma (MM). We retrospectively reviewed all MM patients who received a second ASCT as salvage therapy at our center from March 1992 to December 2009. Eighty-one MM patients received a second ASCT for relapsed MM. The median time to relapse after first transplant was 39 months (9.83-100). All patients received reinduction therapy before the second ASCT. The high-dose regimen given before the second ASCT consisted of melphalan (MEL) alone in the majority. Complete response, very good partial response, and partial response were seen in 7.7%, 39.7%, and 50%, respectively, at day 100 post-ASCT; the median time to relapse after the second ASCT was 19 months. Early deaths occurred in 2.6%. Median progression-free survival (PFS) based on the time to myeloma relapse after first ASCT was 9.83 months (relapse ≤ 24 months) and 17.3 months (relapse ≥ 24 months) (P < .05). Median overall survival (OS) was 28.47 months (relapse ≤ 24 months) and 71.3 months (relapse >24 months) (P = .006). Second ASCT is a feasible and safe option for salvage therapy in MM. The best outcome was observed in patients whose time to progression was >24 months after first ASCT, as these patients had a subsequent PFS lasting over 1 year and an OS of almost 6 years.

Fixed duration vs. prolonged duration treatment after first line therapy in patients with systemic light chain amyloidosis.

BACKGROUND: The main objective of treatment in systemic light chain amyloidosis (AL amyloidosis) is to achieve the best hematological response. Deeper responses are associated with better organ responses and survival. In this study, we analysed the efficacy of prolonged duration treatment after first line in patients with AL amyloidosis. METHODS: Retrospective analysis that included patients older than 18 years with AL amyloidosis. We excluded patients with more than 30% marrow plasmacytosis or concurrent multiple myeloma. Two cohorts identified accordingly if they received or not prolonged treatment after the first line. Survival analysis regarding progression free survival (PFS) and overall survival (OS) estimated with Kaplan-Meier and comparisons between groups with log-rank. RESULTS: Thirty-eight patients were included in the analysis with a median age of 55 years. Twenty-one patients received prolonged duration treatment and 17 did not. In the prolonged duration group, after a median duration of 12 months, the median PFS was 58.8 months. In the fixed duration treatment group, PFS was 30.6 months. The difference was significant with p = .0045 favouring prolonged duration treatment. Organ response was sustained for a longer period in the prolonged duration treatment group. For OS, the difference was not significant. CONCLUSIONS: Prolonged duration treatment in patients with systemic light chain amyloidosis correlated with better PFS and deeper organ responses. Prospective studies are needed to analyse this further.

Sequential Use of Carfilzomib and Pomalidomide in Relapsed Multiple Myeloma: A Report from the Canadian Myeloma Research Group (CMRG) Database.

The treatment of multiple myeloma has dramatically improved due to the availability of novel therapies that are highly effective and are quickly moving into first-line therapy. The Canadian Agency for Drugs and Technologies in Health (CADTH) recently recommended that patients who receive daratumumab should only be eligible to receive either carfilzomib or pomalidomide but not both, for relapsed MM. In order to assess the efficacy of these two agents in the relapsed setting, we utilized our national myeloma database. A total of 121 patients were reviewed, 49 patients received CAR- before POM-based (CAR-POM), and 73 patients received POM- before CAR-based (POM-CAR) therapy. In the groups selected, the median PFS was 4.93 months (95% CI, 2.76-7.07) and 5.36 months (95% CI, 3.75-6.94) for CAR-POM and POM-CAR, respectively. The median OS for patients treated with CAR-POM was 11.01 months (95% CI, 4.50-19.13), and for patients treated with POM-CAR the median OS was 10.98 months (95% CI, 8.98-19.17). In this real-world observational study, we demonstrated that both CAR- and POM-based therapies, irrespective of the order in which they were used, were effective treatment options for patients with advanced relapsed MM.

Carfilzomib usage patterns and outcomes in patients with relapsed multiple myeloma: A multi-institutional report from the Canadian Myeloma Research Group (CMRG) Database.

Carfilzomib is an active and commonly used treatment in patients with multiple myeloma (MM). Using the Canadian Myeloma Research Group Database, we performed a retrospective observational study of patients treated with carfilzomib for relapse of MM in a real-world setting in Canada between years 2007 and 2020. A total of 445 patients were included in this study: the doublet (Kd/p, n = 218) and triplets (KCd, n = 88; KRd, n = 99; KPd/p, n = 40). One hundred and twenty-two (27%) received carfilzomib-based treatment in line 2, 133 (30%) in line 3, 90 (20%) in line 4, and 100 (23%) in line 5 or higher. Carfilzomib was dosed weekly in 40% of patients and twice weekly in 60%. The overall response rate of the entire cohort was 57.7%, with 33.6% of patients achieving very good partial response or better. Median progression-free survival for the overall cohort was 6.3 months with overall survival 19.7 months. This study provides a benchmark for carfilzomib-based regimens in the real world, demonstrating that these regimens are effective in treating patients with relapsed MM.

Survival and Outcomes of Newly Diagnosed Multiple Myeloma Patients Stratified by Transplant Status 2007-2018: Retrospective Analysis from the Canadian Myeloma Research Group Database.

BACKGROUND: Considerable progress has been made in therapeutic options for multiple myeloma (MM). Understanding the current landscape of MM treatment options and associated outcomes in the real world is important in providing key insights into clinical and knowledge gaps which could be targeted for further optimization. METHODS: The Canadian Myeloma Research Group Database (CMRG-DB) is a prospectively maintained disease-specific database with >7000 patients. The objective of this study was to describe the trends in the treatment landscape and outcomes including early mortality, time to next treatment, and overall survival (OS) in each line of treatment stratified by autologous stem cell transplant (ASCT) receipt among newly-diagnosed MM patients in Canada between 2007 and 2018. RESULTS: A total of 5154 patients were identified among which 3030 patients (58.8%) received an upfront ASCT and 2124 (41.2%) did not. At diagnosis, the median age was 64 years and 58.6% were males. Bortezomib and lenalidomide were most frequently used (>50%) in first and second-line treatment respectively among both the ASCT and non-ASCT cohort. The median OS was 122.0 months (95% Cl 115.0-135.0 months) and 54.3 months (95% CI 50.8-58.8 months) for the ASCT and non-ASCT cohort respectively with an incremental decrease in OS in each subsequent line of treatment. CONCLUSION: We present the largest study to date in the Canadian landscape showing the characteristics, therapy usage, and outcomes among MM patients. This information will be critical in benchmarking current outcomes and provide key insight into areas of unmet needs and gaps for improvement of MM patients nationally.

Efficacy of Daratumumab-Containing Regimens Among Patients With Multiple Myeloma Progressing on Lenalidomide Maintenance: Retrospective Analysis.

BACKGROUND: Daratumumab, a monoclonal antibody directed against CD38 is a recent class of drugs introduced into the multiple myeloma therapeutic landscape. While clinical trial data have shown a remarkable impact on outcomes, the efficacy of daratumumab combination therapies in specific clinically relevant subgroups including among patients refractory to lenalidomide maintenance remains unknown. METHODS: In this study, retrospective data were reviewed from the Canadian Myeloma Research Group and the German Munster Myeloma databases to identify patients that received daratumumab in combination with pomalidomide (DPd), lenalidomide (DRd), and bortezomib (DVd) in a population that had relapsed on lenalidomide maintenance postautologous stem cell transplant. The primary aim of the study was to look at outcomes of these patients in different daratumumab combinations. RESULTS: A total of 73 patients were identified. The median age of the patients at the time of daratumumab initiation was 60 (38-72) and 64.4% (n = 47) were men. In the selected cohort, 43.8% (n = 32) were treated with DRd, 31.5% (n = 23) with DVd, and 24.7% (n = 18) with DPd regimen. The median progression-free survival (PFS) of the entire cohort was 15.8 months (95% CI, 12.9-37.1 months). The median PFS of the individual regimens was as follows: DPd 18.9 months (95% CI, 13.7-not reached), DRd 21.7 months (95% CI, 11.6-not reached), and DVd 12.9 months (95% CI, 3.1-not reached). CONCLUSIONS: Daratumumab-containing therapies are effective regimens in patients progressing on lenalidomide maintenance. Additional studies are required to decide the optimal regimen post-lenalidomide maintenance.