A plain language summary of the PERSEUS study of daratumumab plus bortezomib, lenalidomide, and dexamethasone for treating newly diagnosed multiple myeloma.

What is this summary about?: This summary describes the first analysis of the PERSEUS study, which looked at adults with multiple myeloma that had never been treated before, also called newly diagnosed multiple myeloma. Multiple myeloma is a type of cancer in the blood, specifically in plasma cells within the soft, spongy tissue in the center of most bones, called the bone marrow. Researchers wanted to see if adding daratumumab (D) to a standard treatment of three other medicines called VRd, which stands for bortezomib (V), lenalidomide (R), and dexamethasone (d), could stop the multiple myeloma from getting worse and help participants live longer without multiple myeloma. Half of the participants were assigned to the treatment plan with daratumumab; they received D-VRd during initial treatment phases (induction and consolidation), followed by daratumumab as well as lenalidomide (D-R) in the maintenance phase. The other half of participants received treatment without daratumumab; they received VRd induction and consolidation followed by lenalidomide alone (R) maintenance. In addition, all participants were able to receive an autologous stem cell transplant, a procedure used to further help reduce multiple myeloma. What were the results?: At the time of this analysis of PERSEUS, about 4 years after participants started the study, participants who received D-VRd treatment followed by D-R maintenance had a better response to treatment (as measured by specific markers of multiple myeloma) and were more likely to be alive and free from their multiple myeloma getting worse in comparison to participants who received VRd followed by R maintenance. Side effects (unwanted or undesirable effects of treatment) in both treatment groups were in line with the known side effects of daratumumab and VRd. What do the results mean?: The results of the PERSEUS study showed that including daratumumab in D-VRd induction/consolidation and D-R maintenance was better for treating multiple myeloma than the current standard VRd treatment followed by R maintenance alone in adults with a new diagnosis of multiple myeloma who were also able to receive an autologous stem cell transplant. Of importance, there were no unexpected side effects in either group. Clinical Trial Registration: NCT02874742 (GRIFFIN) (ClinicalTrials.gov).^ieng

Progression-free survival as a surrogate endpoint in myeloma clinical trials: an evolving paradigm.

Measurement of overall survival (OS) remains the gold standard for interpreting the impact of new therapies for multiple myeloma in phase 3 trials. However, as outcomes have improved, it is increasingly challenging to use OS as the primary endpoint if timely approval of novel agents is to be ensured to enable maximum benefit for patients. Surrogate endpoints of OS, such as progression-free survival (PFS) and response to treatment, have contributed to approval decisions by the Food and Drug Administration (FDA) and European Medicines Agency as endpoints demonstrating clinical benefit, and the FDA has recently supported the use of minimal residual disease (MRD) as an accelerated approval endpoint in multiple myeloma. This review aims to address situations in which the use of PFS as a surrogate endpoint warrants careful interpretation especially for specific subgroups of patients and considers ways to ensure that studies can be designed to account for possible discordance between PFS and OS. The utility of subgroup analyses, including the potential for those not pre-specified, to identify target populations for new agents is also discussed.

Advances and challenges in anti-cancer vaccines for multiple myeloma.

Multiple myeloma (MM) is a hematological cancer marked by plasma cell accumulation in the bone marrow. Despite treatment advancements, MM remains incurable in most patients. MM-associated immune dysregulation fosters disease progression, prompting research into immunotherapy to combat the disease. An area of immunotherapy investigation is the design of myeloma vaccine therapy to reverse tumor-associated immune suppression and elicit tumor-specific immune responses to effectively target MM cells. This article reviews vaccine immunotherapy for MM, categorizing findings by antigen type and delivery method. Antigens include idiotype (Id), tumor-associated (TAA), tumor-specific (TSA), and whole tumor lysate. Myeloma vaccination has so far shown limited clinical efficacy. However, further studies are essential to optimize various aspects, including antigen and patient selection, vaccine timing and sequencing, and rational combinations with emerging MM treatments.

Estimated Financial Savings From Clinical Studies at Oslo Myeloma Center in the Period 2015-2021.

BACKGROUND: The number of clinical studies in the Western world has been declining the last decade. Clinical studies offer valuable opportunities for cancer patients to access new treatments and serve as arenas for learning and competence development for health care workers. In addition to this, clinical studies can significantly contribute to financial savings for the health care system through the provision of drugs. The extent of these savings have not been evaluated before. MATERIALS AND METHODS: We assessed the financial savings from drugs provided in clinical studies conducted at Oslo Myeloma Center between 2015 and 2021. Only drugs that had marketing license or another equivalent drug with marketing license were considered to estimate savings. RESULTS: A total of 314 patients across 24 different studies were given treatment with drugs possessing marketing license. Drugs approved for clinical use and reimbursed by the national health care system gave a financial saving of 20.3 million USD and was considered a direct saving. Drugs not approved for clinical use, but having equivalent approved alternatives yielded a financial saving of 4.7 million USD. CONCLUSION: Clinical studies not only offer new opportunities for patients and advancements in medical treatment and knowledge but also contribute significantly to financial saving for the health care system through reduced drug expenses.

Consensus guidelines and recommendations for the management and response assessment of chimeric antigen receptor T-cell therapy in clinical practice for relapsed and refractory multiple myeloma: a report from the International Myeloma Working Group Immunotherapy Committee.

Chimeric antigen receptor (CAR) T-cell therapy has shown promise in patients with late-line refractory multiple myeloma, with response rates ranging from 73 to 98%. To date, three products have been approved: Idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel), which are approved by the US Food and Drug Administration, the European Medicines Agency, Health Canada (ide-cel only), and Brazil ANVISA (cilta-cel only); and equecabtagene autoleucel (eque-cel), which was approved by the Chinese National Medical Products Administration. CAR T-cell therapy is different from previous anti-myeloma therapeutics with unique toxic effects that require distinct mitigation strategies. Thus, a panel of experts from the International Myeloma Working Group was assembled to provide guidance for clinical use of CAR T-cell therapy in myeloma. This consensus opinion is from experts in the field of haematopoietic cell transplantation, cell therapy, and multiple myeloma therapeutics.

Ixazomib, Lenalidomide, and Dexamethasone (IRD) Treatment with Cytogenetic Risk-Based Maintenance in Transplant-Eligible Myeloma: A Phase 2 Multicenter Study by the Nordic Myeloma Study Group.

Scarce data exist on double maintenance in transplant-eligible high-risk (HR) newly diagnosed multiple myeloma (NDMM) patients. This prospective phase 2 study enrolled 120 transplant-eligible NDMM patients. The treatment consisted of four cycles of ixazomib-lenalidomide-dexamethasone (IRD) induction plus autologous stem cell transplantation followed by IRD consolidation and cytogenetic risk-based maintenance therapy with lenalidomide + ixazomib (IR) for HR patients and lenalidomide (R) alone for NHR patients. The main endpoint of the study was undetectable minimal residual disease (MRD) with sensitivity of <10-5 by flow cytometry at any time, and other endpoints were progression-free survival (PFS) and overall survival (OS). We present the preplanned analysis after the last patient has been two years on maintenance. At any time during protocol treatment, 28% (34/120) had MRD < 10-5 at least once. At two years on maintenance, 66% of the patients in the HR group and 76% in the NHR group were progression-free (p = 0.395) and 36% (43/120) were CR or better, of which 42% (18/43) had undetectable flow MRD <10-5. Altogether 95% of the patients with sustained MRD <10-5, 82% of the patients who turned MRD-positive, and 61% of those with positive MRD had no disease progression at two years on maintenance (p < 0.001). To conclude, prolonged maintenance with all-oral ixazomib plus lenalidomide might improve PFS in HR patients.

Isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone in patients with relapsed and refractory multiple myeloma: final overall survival analysis.

The primary and prespecified updated analyses of ICARIA-MM (clinicaltrial gov. Identifier: NCT02990338) demonstrated improved progression-free survival (PFS) and a benefit in overall survival (OS) was reported with the addition of isatuximab, an anti-CD38 monoclonal antibody, to pomalidomide-dexamethasone (Pd) in patients with relapsed/refractory multiple myeloma. Here, we report the final OS analysis. This multicenter, randomized, open-label, phase III study included patients who had received and failed ≥2 previous therapies, including lenalidomide and a proteasome inhibitor. Between January 10, 2017, and February 2, 2018, 307 patients were randomized (1:1) to isatuximab-pomalidomide-dexamethasone (Isa-Pd; N=154) or Pd (N=153), stratified based on age (<75 vs. ≥75 years) and number of previous lines of therapy (2-3 vs. >3). At data cutoff for the final OS analysis after 220 OS events (January 27, 2022), median follow-up duration was 52.4 months. Median OS was 24.6 months (95% confidence interval [CI]: 20.3-31.3) with Isa-Pd and 17.7 months (95% CI: 14.4- 26.2) with Pd (hazard ratio=0.78; 95% CI: 0.59-1.02; 1-sided P=0.0319). Despite subsequent daratumumab use in the Pd group and its potential benefit on PFS in the first subsequent therapy line, median PFS2 was significantly longer with Isa-Pd versus Pd (17.5 vs. 12.9 months; log-rank 1-sided P=0.0091). In this analysis, Isa-Pd continued to be efficacious and well tolerated after follow-up of approximately 52 months, contributing to a clinically meaningful, 6.9-month improvement in median OS in patients with relapsed/refractory multiple myeloma.

Health-related quality of life and quality-adjusted progression free survival for carfilzomib and dexamethasone maintenance following salvage autologous stem-cell transplantation in patients with multiple myeloma: a randomized phase 2 trial by the Nordic Myeloma Study Group.

BACKGROUND: Decisions regarding maintenance therapy in patients with multiple myeloma should be based on both treatment efficacy and health-related quality of life (HRQL) consequences. In the CARFI trial, patients with first relapse of multiple myeloma underwent salvage autologous stem cell transplantation (salvage ASCT) before randomization to carfilzomib-dexamethasone maintenance therapy (Kd) or observation. The primary clinical endpoint was time to progression, which was extended by 8 months by Kd. The aim of this paper is to present the all HRQL endpoints of the CARFI trial including the HRQL effect of Kd maintenance therapy relative to observation. The primary HRQL endpoint was assessed by EORTC QLQ-C30 Summary score (QLQ-C30-sum) at 8 months follow-up. A key secondary HRQL endpoint was quality-adjusted progression-free-survival (QAPFS). METHODS: HRQL was assessed with EORTC QLQ-C30, EORTC QLQ-MY20 and FACT/GOG-Ntx at randomization and every second month during follow-up. HRQL data were analyzed with linear mixed effect models until 8 months follow-up. QAPFS per individual was calculated by multiplying progression-free survival (PFS) by two quality-adjustment metrics, the QLQ-C30-sum and EORTC Quality of Life Utility Measure-Core 10 dimensions (QLU-C10D). The QAPFS per treatment group was estimated with the Kaplan-Meier method. P < 0.05 was used for statistical significance, and a between-group minimal important difference of 10 points was interpreted as clinically relevant for the QLQ-C30-sum. RESULTS: 168 patients were randomized. HRQL questionnaire compliance was 93%. For the QLQ-C30-sum, the difference of 4.62 points (95% confidence interval (CI) -8.9: -0.4, p = 0.032) was not clinically relevant. PFS was 19.3 months for the Kd maintenance group and 16.8 months for the observation group; difference = 2.5 months (95% CI 0.5; 4.5). QAPFS based on the QLQ-C30-sum for the Kd maintenance group was 18.0 months (95% CI 16.4; 19.6) and for the observation group 15.0 months (95% CI 13.5; 16.5); difference = 3.0 months (95% CI 0.8-5.3). QAPFS based on the QLU-C10D for the Kd maintenance group was 17.5 months (95% CI 15.9; 19.2) and 14.0 months (95% CI 12.4; 15.5) for the observation group; difference = 3.5 months (95% CI 1.1-5.9). CONCLUSIONS: Kd maintenance therapy after salvage ASCT did not adversely affect overall HRQL, but adjustment for HRQL reduced the PFS compared to unadjusted PFS. PFS of maintenance therapy should be quality-adjusted to balance the benefits and HRQL impact.

Efficacy and safety of melflufen plus daratumumab and dexamethasone in relapsed/refractory multiple myeloma: results from the randomized, open-label, phase III LIGHTHOUSE study.

Melphalan flufenamide (melflufen), a first-in-class alkylating peptide-drug conjugate, plus dexamethasone was approved in Europe for use in patients with triple-class refractory relapsed/refractory multiple myeloma (RRMM) with ≥3 prior lines of therapy and without prior autologous stem cell transplantation (ASCT) or with a time to progression >36 months after prior ASCT. The randomized LIGHTHOUSE study (NCT04649060) assessed melflufen plus daratumumab and dexamethasone (melflufen group) versus daratumumab in patients with RRMM with disease refractory to an immunomodulatory agent and a proteasome inhibitor or who had received ≥3 prior lines of therapy including an immunomodulatory agent and a proteasome inhibitor. A partial clinical hold issued by the US Food and Drug Administration for all melflufen studies led to financial constraints and premature study closure on February 23rd 2022 (data cut-off date). In total, 54 of 240 planned patients were randomized (melflufen group, N=27; daratumumab group, N=27). Median progression-free survival (PFS) was not reached in the melflufen group versus 4.9 months in the daratumumab group (Hazard Ratio: 0.18 [95% Confidence Interval, 0.05-0.65]; P=0.0032) at a median follow-up time of 7.1 and 6.6 months, respectively. Overall response rate (ORR) was 59% in the melflufen group versus 30% in the daratumumab group (P=0.0300). The most common grade ≥3 treatment-emergent adverse events in the melflufen group versus daratumumab group were neutropenia (50% vs. 12%), thrombocytopenia (50% vs. 8%), and anemia (32% vs. 19%). Melflufen plus daratumumab and dexamethasone demonstrated superior PFS and ORR versus daratumumab in RRMM and a safety profile comparable to previously published melflufen studies.

Melflufen in relapsed/refractory multiple myeloma refractory to prior alkylators: A subgroup analysis from the OCEAN study.

Melphalan flufenamide (melflufen), a first-in-class alkylating peptide-drug conjugate, plus dexamethasone demonstrated superior progression-free survival (PFS), but not overall survival (OS), versus pomalidomide plus dexamethasone in relapsed/refractory multiple myeloma in the OCEAN study. Time to progression (TTP) <36 months after a prior autologous stem cell transplantation (ASCT) was a negative prognostic factor for OS with melflufen. This post hoc exploratory analysis evaluated patients refractory to prior alkylators (e.g., cyclophosphamide and melphalan) in OCEAN. In 153 patients refractory to prior alkylators (melflufen, n = 78; pomalidomide, n = 75), the melflufen and pomalidomide arms had similar median PFS (5.6 months [95% CI, 4.2-8.3] vs. 4.7 months [95% CI, 3.1-7.3]; hazard ratio [HR], 0.92 [95% CI, 0.63-1.33]) and OS (23.4 months [95% CI, 14.4-31.7] vs. 20.0 months [95% CI, 12.0-28.7]; HR, 0.92 [95% CI, 0.62-1.38]). Among alkylator-refractory patients with a TTP ≥ 36 months after a prior ASCT or no prior ASCT (melflufen, n = 54; pomalidomide, n = 53), the observed median PFS and OS were longer in the melflufen arm than the pomalidomide arm. The safety profile of melflufen was consistent with previous reports. These results suggest that melflufen is safe and effective in patients with alkylator-refractory disease, suggesting differentiated activity from other alkylators.

Pomalidomide, Bortezomib, and Dexamethasone in Lenalidomide-Pretreated Multiple Myeloma: A Subanalysis of OPTIMISMM by Frailty and Bortezomib Dose Adjustment.

INTRODUCTION: A proportion of patients with multiple myeloma (MM) are older and/or have comorbidities, requiring dose adjustments. Data from OPTIMISMM (NCT01734928) supported the use of pomalidomide, bortezomib, and dexamethasone (PVd) for treating relapsed/refractory MM. This subanalysis of OPTIMISMM assessed outcome by frailty and/or bortezomib dose adjustment. METHODS: Patient frailty (nonfrail vs. frail) was classified using age, Charlson Comorbidity Index, and Eastern Cooperative Oncology Group performance status. Data from patients requiring a bortezomib dose reduction, interruption, and/or withdrawal during PVd treatment were assessed. RESULTS: Among 559 patients, 93 of 281 (33.1%) and 93 of 278 (33.5%) patients who received PVd and bortezomib and dexamethasone (Vd), respectively, were frail. Overall response rate (ORR) and median progression-free survival (PFS) were higher in nonfrail vs. frail with PVd treatment (ORR, 82.8% vs. 79.6%; PFS, 14.7 vs. 9.7 months); significantly higher than with Vd regardless of frailty. Grade ≥ 3 treatment-emergent adverse events (TEAEs) were higher with PVd vs. Vd, regardless of frailty. Discontinuations of PVd were lower in nonfrail vs. frail patients (19.2% vs. 30.1%); the median duration of treatment was similar (DoT; 8.8 vs. 8.9 months, respectively). Patients who received PVd with a bortezomib dose adjustment (n = 240) had a longer median DoT (9.3 vs. 4.5 months) and PFS (12.1 vs. 8.4 months) vs. those without. CONCLUSION: Frail patients treated with PVd demonstrated a higher ORR and a longer PFS and DoT vs. Vd, despite a higher frequency of grade ≥ 3 TEAEs leading to pomalidomide, bortezomib, and/or dexamethasone discontinuation. Therefore, PVd treatment may improve patient outcomes, regardless of frailty.

Daratumumab, Bortezomib, Lenalidomide, and Dexamethasone for Multiple Myeloma.

BACKGROUND: Daratumumab, a monoclonal antibody targeting CD38, has been approved for use with standard myeloma regimens. An evaluation of subcutaneous daratumumab combined with bortezomib, lenalidomide, and dexamethasone (VRd) for the treatment of transplantation-eligible patients with newly diagnosed multiple myeloma is needed. METHODS: In this phase 3 trial, we randomly assigned 709 transplantation-eligible patients with newly diagnosed multiple myeloma to receive either subcutaneous daratumumab combined with VRd induction and consolidation therapy and with lenalidomide maintenance therapy (D-VRd group) or VRd induction and consolidation therapy and lenalidomide maintenance therapy alone (VRd group). The primary end point was progression-free survival. Key secondary end points were a complete response or better and minimal residual disease (MRD)-negative status. RESULTS: At a median follow-up of 47.5 months, the risk of disease progression or death in the D-VRd group was lower than the risk in the VRd group. The estimated percentage of patients with progression-free survival at 48 months was 84.3% in the D-VRd group and 67.7% in the VRd group (hazard ratio for disease progression or death, 0.42; 95% confidence interval, 0.30 to 0.59; P<0.001); the P value crossed the prespecified stopping boundary (P = 0.0126). The percentage of patients with a complete response or better was higher in the D-VRd group than in the VRd group (87.9% vs. 70.1%, P<0.001), as was the percentage of patients with MRD-negative status (75.2% vs. 47.5%, P<0.001). Death occurred in 34 patients in the D-VRd group and 44 patients in the VRd group. Grade 3 or 4 adverse events occurred in most patients in both groups; the most common were neutropenia (62.1% with D-VRd and 51.0% with VRd) and thrombocytopenia (29.1% and 17.3%, respectively). Serious adverse events occurred in 57.0% of the patients in the D-VRd group and 49.3% of those in the VRd group. CONCLUSIONS: The addition of subcutaneous daratumumab to VRd induction and consolidation therapy and to lenalidomide maintenance therapy conferred a significant benefit with respect to progression-free survival among transplantation-eligible patients with newly diagnosed multiple myeloma. (Funded by the European Myeloma Network in collaboration with Janssen Research and Development; PERSEUS ClinicalTrials.gov number, NCT03710603; EudraCT number, 2018-002992-16.).

Difficult-to-treat patients with relapsed/refractory multiple myeloma: A review of clinical trial results.

Overall outcomes for multiple myeloma have improved due to the availability of new therapies, but patients with relapsed/refractory multiple myeloma harbouring certain factors continue to pose a therapeutic challenge. These challenging features include high-risk cytogenetics, renal impairment, patient characteristics such as age and frailty, and extramedullary disease. Prior refractory status and number of prior lines add further complexity to the treatment of these patients. While newer regimens are available and have suggested efficacy in these patient populations through subgroup analyses, differences in trial definitions and cut-offs make meaningful comparisons difficult. This review aims to examine the available clinical trial data for patients with high-risk cytogenetics, renal impairment, age and frailty and extramedullary disease.

Treatment of primary plasma cell leukaemia with carfilzomib and lenalidomide-based therapy (EMN12/HOVON-129): final analysis of a non-randomised, multicentre, phase 2 study.

BACKGROUND: Primary plasma cell leukaemia is a rare and aggressive plasma cell disorder with a poor prognosis. The aim of the EMN12/HOVON-129 study was to improve the outcomes of patients with primary plasma cell leukaemia by incorporating carfilzomib and lenalidomide in induction, consolidation, and maintenance therapy. METHODS: The EMN12/HOVON-129 study is a non-randomised, phase 2, multicentre study conducted at 19 academic centres and hospitals in seven European countries (Belgium, Czech Republic, Denmark, Italy, Norway, The Netherlands, and the UK) for previously untreated patients with primary plasma cell leukaemia aged 18 years or older. Inclusion criteria were newly diagnosed primary plasma cell leukaemia (defined as >2 ×109 cells per L circulating monoclonal plasma cells or plasmacytosis >20% of the differential white cell count) and WHO performance status 0-3. Patients aged 18-65 years (younger patients) and 66 years or older (older patients) were treated in age-specific cohorts and were analysed separately. Younger patients were treated with four 28-day cycles of carfilzomib (36 mg/m2 intravenously on days 1, 2, 8, 9, 15, and 16), lenalidomide (25 mg orally on days 1-21), and dexamethasone (20 mg orally on days 1, 2, 8, 9, 15, 16, 22, and 23). Carfilzomib-lenalidomide-dexamethasone (KRd) induction was followed by double autologous haematopoietic stem-cell transplantation (HSCT), four cycles of KRd consolidation, and then maintenance with carfilzomib (27 mg/m2 intravenously on days 1, 2, 15, and 16 for the first 12 28-day cycles, and then 56 mg/m2 on days 1 and 15 in all subsequent cycles) and lenalidomide (10 mg orally on days 1-21) until progression. Patients who were eligible for allogeneic HSCT, could also receive a single autologous HSCT followed by reduced-intensity conditioning allogeneic HSCT and then carfilzomib-lenalidomide maintenance. Older patients received eight cycles of KRd induction followed by maintenance therapy with carfilzomib and lenalidomide until progression. The primary endpoint was progression-free survival. The primary analysis population was the intention-to-treat population, irrespective of the actual treatment received. Data from all participants who received any study drug were included in the safety analyses. The trial was registered at www.trialregister.nl (until June 2022) and https://trialsearch.who.int/ as NTR5350; recruitment is complete and this is the final analysis. FINDINGS: Between Oct 23, 2015, and Aug 5, 2021, 61 patients were enrolled and received KRd induction treatment (36 patients aged 18-65 years [20 (56%) were male and 16 (44%) female], and 25 aged ≥66 years [12 (48%) were male and 13 (52%) female]). With a median follow-up of 43·5 months (IQR 27·7-67·8), the median progression-free survival was 15·5 months (95% CI 9·4-38·4) for younger patients. For older patients, median follow-up was 32·0 months (IQR 24·7-34·6), and median progression-free survival was 13·8 months (95% CI 9·2-35·5). Adverse events were most frequently observed directly after treatment initiation, with infections (two of 36 (6%) younger patients and eight of 25 (32%) older patients) and respiratory events (two of 36 [6%] younger patients and four of 25 [16%] older patients) being the most common grade 3 or greater events during the first four KRd cycles. Treatment-related serious adverse events were reported in 26 (72%) of 36 younger patients and in 19 (76%) of 25 older patients, with infections being the most common. Treatment-related deaths were reported in none of the younger patients and three (12%) of the older patients (two infections and one unknown cause of death). INTERPRETATION: Carfilzomib and lenalidomide-based therapy provides improved progression-free survival compared with previously published data. However, results remain inferior in primary plasma cell leukaemia compared with multiple myeloma, highlighting the need for new studies incorporating novel immunotherapies. FUNDING: Dutch Cancer Society, Celgene (a BMS company), and AMGEN.

Intensifying treatment in PET-positive multiple myeloma patients after upfront autologous stem cell transplantation.

18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET) positivity after first-line treatment with autologous stem cell transplantation (ASCT) in multiple myeloma is strongly correlated with reduced progression-free and overall survival. However, PET-positive patients who achieve PET negativity after treatment seem to have comparable outcomes to patients who were PET negative at diagnosis. Hence, giving PET-positive patients additional treatment may improve their outcome. In this phase II study, we screened first-line patients with very good partial response (VGPR) or better after ASCT with PET. PET-positive patients received four 28-day cycles of carfilzomib-lenalidomide-dexamethasone (KRd). Flow cytometry-based minimal residual disease (MRD) analysis was performed before and after treatment for correlation with PET. Overall, 159 patients were screened with PET. A total of 53 patients (33%) were PET positive and 57% of PET-positive patients were MRD negative, demonstrating that these response assessments are complementary. KRd consolidation converted 33% of PET-positive patients into PET negativity. MRD-negative patients were more likely to convert than MRD-positive patients. In summary, PET after ASCT detected residual disease in a substantial proportion of patients in VGPR or better, even in patients who were MRD negative, and KRd consolidation treatment changed PET status in 33% of patients.