EVIDENCE meta-analysis: evaluating minimal residual disease as an intermediate clinical endpoint for multiple myeloma.

Estimating progression-free survival (PFS) and overall survival (OS) superiority during clinical trials of multiple myeloma (MM) has become increasingly challenging as novel therapeutics have improved patient outcomes. Thus, it is imperative to identify earlier endpoint surrogates that are predictive of long-term clinical benefit to expedite development of more effective therapies. Minimal residual disease (MRD)-negativity is a common intermediate endpoint that has shown prognostic value for clinical benefit in trials of patients with multiple myeloma (MM). This meta-analysis was based on the FDA guidance for considerations for a meta-analysis of MRD as a clinical endpoint and evaluates MRD-negativity as an early endpoint reasonably likely to predict long-term clinical benefit. Eligible studies were phase 2 or 3 randomized controlled clinical trials measuring MRD negativity as an endpoint in patients with MM, with follow-up of ≥6 months following an a priori defined time point of 12±3 months post-randomization. Eight newly diagnosed MM-(NDMM)-studies evaluating 4,907 patients were included. Trial-level associations between MRD-negativity and PFS were R2WLSiv (95% CI) 0.67 (0.43-0.91) and R2copula 0.84 (0.64->0.99) at the 12-month timepoint. The individual-level association between 12-month MRD negativity and PFS resulted in a global odds ratio of 4.02 (95% CI: 2.57-5.46). For relapse/refractory MM-(RRMM), there were four studies included, and the individual-level association between 12-month MRD negativity and PFS resulted in a global odds ratio of 7.67 (4.24-11.10). A clinical trial demonstrating a treatment effect on MRD is reasonably likely to eventually demonstrate a treatment effect on PFS, suggesting that MRD may be an early clinical endpoint reasonably likely to predict clinical benefit in MM, that may be used to support accelerated approval and thereby expedite the availability of new drugs to patients with MM.

Minimal Residual Disease-Adapted Therapy in Multiple Myeloma: Current Evidence and Opinions.

PURPOSE OF REVIEW: Multiple myeloma (MM) is a biologically heterogeneous malignancy with relatively uniform treatment paradigms. This review aims to assess the growing role of Minimal Residual Disease (MRD) assessment in facilitating response-adapted therapeutic decision making to individualize therapy in MM. RECENT FINDINGS: MRD has been repeatedly demonstrated to provide strong prognostic information, superseding traditional IMWG response criteria. The use of MRD to modulate therapy remains controversial. Here, we review the existing landscape of MRD-adapted trial designs in both induction/consolidation and maintenance settings, including recent data from influential studies and retrospective analyses. We navigate existing data, leverage the increased resolution of longitudinal MRD assessments, and comment on trials in progress to explain our current utilization of MRD in the clinic. MRD transcends traditional response assessments by providing a window into disease-treatment interaction over time. As a strong patient-level surrogate, MRD has limited current use in individualizing treatment, but is poised to comprehensively shape treatment strategies at many key points in a patient's MM course.

Diagnostic performance of 18 F-FDG-PET/CT compared to standard skeletal survey for detecting bone destruction in smouldering multiple myeloma: time to move forward.

Skeletal survey (SS) continues to be used in the community to detect bone disease in patients with multiple myeloma (MM). While the false-negative rate is high, the specificity of SS is less well characterised. Here, we compare the diagnostic accuracy of SS compared to 18 F-FDG-PET/CT (positron emission tomography/computed tomography) in 79 patients referred to our tertiary centre with a diagnosis of smouldering MM. SS had a specificity of 83·1% (95% confidence interval: 72·0-90·5%). This study reinforces the importance of using more specific imaging techniques to avoid inaccurate diagnosis that could lead to the risks associated with unnecessary therapy in patients with smouldering MM.

Avelumab, a PD-L1 Inhibitor, in Combination with Hypofractionated Radiotherapy and the Abscopal Effect in Relapsed Refractory Multiple Myeloma.

LESSONS LEARNED: Despite the initial optimism for using immune checkpoint inhibition in the treatment of multiple myeloma, subsequent clinical studies have been disappointing. Preclinical studies have suggested that priming the immune system with various modalities in addition to checkpoint inhibition may overcome the relative T-cell exhaustion or senescence; however, in this small data set, radiotherapy with checkpoint inhibition did not appear to activate the antitumor immune response. BACKGROUND: Extramedullary disease (EMD) is recognized as an aggressive subentity of multiple myeloma (MM) with a need for novel therapeutic approaches. We therefore designed a proof-of-principle pilot study to evaluate the synergy between the combination of the anti-PD-L1, avelumab, and concomitant hypofractionated radiotherapy. METHODS: This was a single-arm phase II Simon two-stage single center study that was prematurely terminated because of the COVID-19 pandemic after enrolling four patients. Key eligibility included patients with relapsed/refractory multiple myeloma (RRMM) who had exhausted or were not candidates for standard therapy and had at least one lesion amenable to radiotherapy. Patients received avelumab until progression or intolerable toxicity and hypofractionated radiotherapy to a focal lesion in cycle 2. Radiotherapy was delayed until cycle 2 to allow the avelumab to reach a study state, given the important observation from previous studies that concomitant therapy is needed for the abscopal effect. RESULTS: At a median potential follow-up of 10.5 months, there were no objective responses, one minimal response, and two stable disease as best response. The median progression-free survival (PFS) was 5.3 months (95% confidence interval [CI]: 2.5-7.1 months), and no deaths occurred. There were no grade ≥3 and five grade 1-2 treatment-related adverse events. CONCLUSION: Avelumab in combination with radiotherapy for patients with RRMM and EMD was associated with very modest systemic clinical benefit; however, patients did benefit as usual from local radiotherapy. Furthermore, the combination was very well tolerated compared with historical RRMM treatment regimens.

The role of high-dose melphalan with autologous stem-cell transplant in multiple myeloma: is it time for a paradigm shift?

Recent advances in multiple myeloma include numerous approvals of novel therapies with unprecedented efficacy, a rapid and sustained tempo of new drug development, and further refinements to prognostication to include minimal residual disease (MRD) testing and improved risk stratification. The upfront use of immunomodulatory drug and proteasome inhibitor combinations followed by maintenance has resulted in transformative clinical benefit. Four-drug regimens incorporating monoclonal antibodies are reporting unprecedented rates of complete response and MRD negativity in the absence of intensification. In the context of these advances, the added value of high-dose melphalan with autologous stem-cell transplant (HDM-ASCT) is a key question. From a safety standpoint, HDM-ASCT is associated with both acute toxicities that reduce quality of life and long-term toxicities that may limit life expectancy for some patients. The present review discusses the recent advances in induction therapy, the impact of these advances on HDM-ASCT, the evolving role of MRD testing and the short- and long-term risks of HDM-ASCT. Recognising that prospective data remains limited, we suggest that HDM-ASCT not be considered mandatory for eligible newly diagnosed patients who are treated with highly efficacious regimens and achieve deep responses, but rather be held in reserve without early exposure to the clinical and genomic toxicity inherent to this approach.

Stability and uniqueness of clonal immunoglobulin CDR3 sequences for MRD tracking in multiple myeloma.

Minimal residual disease (MRD) tracking, by next generation sequencing of immunoglobulin sequences, is moving towards clinical implementation in multiple myeloma. However, there is only sparse information available to address whether clonal sequences remain stable for tracking over time, and to what extent light chain sequences are sufficiently unique for tracking. Here, we analyzed immunoglobulin repertoires from 905 plasma cell myeloma and healthy control samples, focusing on the third complementarity determining region (CDR3). Clonal heavy and/or light chain expression was identified in all patients at baseline, with one or more subclones related to the main clone in 3.2%. In 45 patients with 101 sequential samples, the dominant clonal CDR3 sequences remained identical over time, despite differential clonal evolution by whole exome sequencing in 49% of patients. The low frequency of subclonal CDR3 variants, and absence of evolution over time in active multiple myeloma, indicates that tumor cells at this stage are not under selective pressure to undergo antibody affinity maturation. Next, we establish somatic hypermutation and non-templated insertions as the most important determinants of light chain clonal uniqueness, identifying a potentially trackable sequence in the majority of patients. Taken together, we show that dominant clonal sequences identified at baseline are reliable biomarkers for long-term tracking of the malignant clone, including both IGH and the majority of light chain clones.

Delaying the use of high-dose melphalan with stem cell rescue in multiple myeloma is ready for prime time.

The significant advances made in the treatment of multiple myeloma (MM) have allowed for a paradigm shift away from the early use of high-dose melphalan with autologous stem cell transplant (HDM-ASCT). In 2015 alone, the US Food and Drug Administration (FDA) approved 4 novel drugs for MM. Novel drugs and regimens have shown unprecedented efficacy, which has increased the tempo of new drug development. Furthermore, the FDA recently approved a diagnostic test to detect minimal residual disease (MRD) that will allow community clinicians to conduct real-time testing of MRD. Most importantly, frontline regimens based on immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have shown a large clinical benefit. The next era has begun, as several 4-drug combinations that include monoclonal antibodies are being evaluated in clinical trials in the attempt to replace HDM-ASCT in the treatment of MM. We and others have therefore questioned the need for early HDM-ASCT, especially in light of the possible complications. HDM-ASCT is associated not only with acute toxicities-cytopenia, infection, and even death-but also an increased risk of developing secondary cancers. This article discusses the historic context of HDM-ASCT, the modern role of HDM-ASCT given the availability of highly sensitive MRD testing, and the likely future of quadruplet treatment. In summary, patients who attain deep responses using IMiD- and PI-based regimens may not require early HDM-ASCT. A delayed approach to this treatment is acceptable, and might be preferred by patients.

FDA Approval Summary: Nivolumab for the Treatment of Metastatic Non-Small Cell Lung Cancer With Progression On or After Platinum-Based Chemotherapy.

UNLABELLED: : On October 9, 2015, the U.S. Food and Drug Administration expanded the nivolumab metastatic non-small cell lung cancer (NSCLC) indication to include patients with nonsquamous NSCLC after a 3.25-month review timeline. Approval was based on demonstration of an improvement in overall survival (OS) in an international, multicenter, open-label, randomized trial comparing nivolumab to docetaxel in patients with metastatic nonsquamous NSCLC with progression on or after platinum-based chemotherapy. The CheckMate 057 trial enrolled 582 patients who were randomized (1:1) to receive nivolumab or docetaxel. Nivolumab demonstrated improved OS compared with docetaxel at the prespecified interim analysis with a hazard ratio (HR) of 0.73 (p = .0015), and a median OS of 12.2 months (95% CI: 9.7-15.0 months) in patients treated with nivolumab compared with 9.4 months (95% CI: 8.0-10.7 months) in patients treated with docetaxel. A statistically significant improvement in objective response rate (ORR) was also observed, with an ORR of 19% (95% CI: 15%-24%) in the nivolumab arm and 12% (95% CI: 9%-17%) in the docetaxel arm. The median duration of response was 17 months in the nivolumab arm and 6 months in the docetaxel arm. Progression-free survival was not statistically different between arms. A prespecified retrospective subgroup analysis suggested that patients with programmed cell death ligand 1-negative tumors treated with nivolumab had similar OS to those treated with docetaxel. The toxicity profile of nivolumab was consistent with the known immune-mediated adverse event profile except for 1 case of grade 5 limbic encephalitis, which led to a postmarketing requirement study to better characterize immune-mediated encephalitis. IMPLICATIONS FOR PRACTICE: Based on the results from the CheckMate 057 clinical trial, nivolumab represents a new treatment option for patients requiring second-line treatment for metastatic non-small cell lung cancer. The role of nivolumab in patients with sensitizing epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) alterations is less clear. Until dedicated studies are performed to better characterize the role and sequence of programmed cell death 1 (PD-1) therapy, patients with EGFR or ALK alterations should have progressed on appropriate targeted therapy before initiating PD-1 inhibitor therapy. Some patients whose tumors lack programmed cell death ligand 1 (PD-L1) expression also appear to have durable responses. The U.S. Food and Drug Administration granted approval to Dako's PD-L1 test, PD-L1 IHC 28-8 pharmDx, which the applicant claimed as a nonessential complementary diagnostic for nivolumab use.

Benefit-Risk Summary of Crizotinib for the Treatment of Patients With ROS1 Alteration-Positive, Metastatic Non-Small Cell Lung Cancer.

UNLABELLED: : On March 11, 2016, after an expedited 5-month review, the U.S. Food and Drug Administration expanded the crizotinib metastatic non-small cell lung cancer (mNSCLC) indication to include the treatment of patients whose tumors harbor a ROS1 rearrangement. The approval was based on a clinically meaningful, durable objective response rate (ORR) in a multicenter, single-arm clinical trial (ROS1 cohort of Trial PROFILE 1001) in patients with ROS1-positive mNSCLC. The trial enrolled 50 patients (age range: 25-77 years) whose tumors were prospectively determined to have a ROS1 gene rearrangement by break-apart fluorescence in situ hybridization (96%) or reverse transcriptase polymerase chain reaction (4%) clinical trial assays. Crizotinib demonstrated an ORR of 66% (95% confidence interval [CI]: 51%-79%) with a median duration of response of 18.3 months by independent radiology review and 72% (95% CI: 58%-84%) by investigator review. Patients received crizotinib 250 mg twice daily and had a median duration of exposure of 34.4 months. The toxicity profile in ROS1-positive patients was generally consistent with the randomized safety data in the U.S. Product Insert from two ALK-positive mNSCLC trials. The most common (≥25%) adverse reactions and laboratory test abnormalities included vision disorders, elevation of alanine transaminase and aspartate transaminase levels, nausea, hypophosphatemia, diarrhea, edema, vomiting, constipation, neutropenia, and fatigue. There were no treatment-related deaths. A favorable benefit-to-risk evaluation led to the traditional approval of crizotinib for this new supplemental indication. IMPLICATIONS FOR PRACTICE: Given the results from the ROS1 cohort of the clinical trial PROFILE 1001, crizotinib represents a new treatment option and the first approved therapy for patients with metastatic non-small cell lung cancer whose tumors are ROS1 positive. Crizotinib demonstrated efficacy irrespective of prior treatment status.

FDA approval summary: crizotinib for the treatment of metastatic non-small cell lung cancer with anaplastic lymphoma kinase rearrangements.

On August 26, 2011, crizotinib received accelerated approval for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) that is ALK-positive as detected by a test approved by the U.S. Food and Drug Administration (FDA). Approval was based on two single-arm trials demonstrating objective response rates (ORRs) of 50% and 61% and median response durations of 42 and 48 weeks. On November 20, 2013, crizotinib received regular approval based on confirmation of clinical benefit in study A8081007, a randomized trial in 347 patients with ALK-positive advanced NSCLC who had previously received one platinum-containing regimen. Patients were assigned (1:1) to receive crizotinib 250 mg orally twice daily or standard of care (docetaxel or pemetrexed). The primary endpoint was progression-free survival (PFS) determined by independent radiology review; secondary endpoints were ORR and overall survival (OS). PFS was significantly longer in the crizotinib arm, with median PFS of 7.7 and 3.0 months in the crizotinib and chemotherapy arms, respectively, and a 46% absolute increase in ORR but no difference in OS between treatment arms at the interim analysis. The most common adverse drug reactions (>25%) in crizotinib-treated patients were vision disorders, nausea, diarrhea, vomiting, constipation, edema, elevated transaminases, and fatigue. The most serious toxicities of crizotinib were hepatotoxicity, interstitial lung disease or pneumonitis, and QT-interval prolongation. Crizotinib's rapid clinical development program (6 years from identification of ALK rearrangements in a subset of NSCLC to full FDA approval) is a model of efficient drug development in this new era of molecularly targeted oncology therapy.

Smoldering multiple myeloma: pathophysiologic insights, novel diagnostics, clinical risk models, and treatment strategies.

Smoldering multiple myeloma (SMM) is a plasma cell disorder first described in 1980 when 6 patients were observed to meet the diagnostic criteria of multiple myeloma, defined as bone marrow plasmacytosis of 10% or greater or M protein level of 3 g/dL or greater, but did not have end-organ damage. Subsequent studies showed that the cumulative risk of SMM progression to symptomatic myeloma in 15 years was 73%. Since this time, advances have been made in understanding the biology of progression; namely, the contribution of branching evolution and microenvironment models to clonal heterogeneity. In parallel to this, clinical risk models using standard platforms of serum, bone marrow, and fluorescence in situ hybridization markers along with newer technologies of flow cytometry, gene expression profiling, and magnetic resonance imaging have been developed for prognostic stratification. Treatment has extended to the early myeloma category owing to more sensitive diagnostic approaches. The development of novel treatments will have to take into consideration our current knowledge of biological transformation. While it may be attractive to initiate early treatment in light of recent studies for high-risk SMM patients, clinical trial evidence of efficacy vs toxicity is still in its infancy. In our opinion, high-risk SMM patients should be strongly encouraged to enroll in treatment clinical trials, but treatment with unapproved agents or indications is not supported outside of trials.

Emerging Strategies for the Prevention of Immune Toxicities Associated with T cell-Engaging Cancer Therapies.

SUMMARY: Immune-related toxicities including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are common side effects of bispecific antibody and chimeric antigen receptor (CAR) T-cell therapies of hematologic malignancies. As anti-inflammatory therapy (the standard of care) is variably effective in mitigating these toxicities after onset, here we discuss emerging evidence for shifting the strategy from mitigation to prevention.

Genomic Profiling to Contextualize the Results of Intervention for Smoldering Multiple Myeloma.

PURPOSE: Early intervention for High-Risk Smoldering Multiple Myeloma (HR-SMM) achieves deep and prolonged responses. It is unclear if beneficial outcomes are due to treatment of less complex, susceptible disease or inaccuracy in clinical definition of cases entered. EXPERIMENTAL DESIGN: Here, we interrogated whole genome and whole exome sequencing for 54 patients across two HR-SMM interventional studies (NCT01572480, NCT02279394). RESULTS: We reveal that the genomic landscape of treated HR-SMM is generally simple as compared to Newly Diagnosed (ND)MM counterparts with less inactivation of tumor suppressor genes, RAS pathway mutations, MYC disruption, and APOBEC contribution. The absence of these events parallels that of indolent precursor conditions, possibly explaining overall excellent outcomes. However, some patients harboring genomic complexity fail to sustain response and experience resistant, progressive disease. Overall, clinical risk scores do not effectively discriminate between genomically indolent and aggressive disease. CONCLUSIONS: Genomic profiling can contextualize the advantage of early intervention in SMM and guide personalization of therapy.

Genomic Classification and Individualized Prognosis in Multiple Myeloma.

PURPOSE: Outcomes for patients with newly diagnosed multiple myeloma (NDMM) are heterogenous, with overall survival (OS) ranging from months to over 10 years. METHODS: To decipher and predict the molecular and clinical heterogeneity of NDMM, we assembled a series of 1,933 patients with available clinical, genomic, and therapeutic data. RESULTS: Leveraging a comprehensive catalog of genomic drivers, we identified 12 groups, expanding on previous gene expression-based molecular classifications. To build a model predicting individualized risk in NDMM (IRMMa), we integrated clinical, genomic, and treatment variables. To correct for time-dependent variables, including high-dose melphalan followed by autologous stem-cell transplantation (HDM-ASCT), and maintenance therapy, a multi-state model was designed. The IRMMa model accuracy was significantly higher than all comparator prognostic models, with a c-index for OS of 0.726, compared with International Staging System (ISS; 0.61), revised-ISS (0.572), and R2-ISS (0.625). Integral to model accuracy was 20 genomic features, including 1q21 gain/amp, del 1p, TP53 loss, NSD2 translocations, APOBEC mutational signatures, and copy-number signatures (reflecting the complex structural variant chromothripsis). IRMMa accuracy and superiority compared with other prognostic models were validated on 256 patients enrolled in the GMMG-HD6 (ClinicalTrials.gov identifier: NCT02495922) clinical trial. Individualized patient risks were significantly affected across the 12 genomic groups by different treatment strategies (ie, treatment variance), which was used to identify patients for whom HDM-ASCT is particularly effective versus patients for whom the impact is limited. CONCLUSION: Integrating clinical, demographic, genomic, and therapeutic data, to our knowledge, we have developed the first individualized risk-prediction model enabling personally tailored therapeutic decisions for patients with NDMM.

MRD and Plasma Cell Dynamics after CAR T-cell Therapy in Myeloma.

SUMMARY: In this issue, Paiva and colleagues characterize the dynamics of minimal residual disease (MRD) and clinical responses during chimeric antigen receptor (CAR) T-cell therapy of relapsed/refractory multiple myeloma. Although both correlate with prolonged progression-free survival, MRD is reached faster in the bone marrow than complete response in peripheral blood; consequently, the study addresses the need for future guidelines to explore new MRD-negative definitions that are independent of the monoclonal (M) protein to overcome this limitation, particularly in clinical trials using early depth of response as an endpoint. See related article by Paiva et al., p. 365 (1).

Immunophenotypic correlates of sustained MRD negativity in patients with multiple myeloma.

The role of the immune microenvironment in maintaining disease remission in patients with multiple myeloma (MM) is not well understood. In this study, we comprehensively profile the immune system in patients with newly diagnosed MM receiving continuous lenalidomide maintenance therapy with the aim of discovering correlates of long-term treatment response. Leveraging single-cell RNA sequencing and T cell receptor ß sequencing of the peripheral blood and CyTOF mass cytometry of the bone marrow, we longitudinally characterize the immune landscape in 23 patients before and one year after lenalidomide exposure. We compare patients achieving sustained minimal residual disease (MRD) negativity to patients who never achieved or were unable to maintain MRD negativity. We observe that the composition of the immune microenvironment in both the blood and the marrow varied substantially according to both MRD negative status and history of autologous stem cell transplant, supporting the hypothesis that the immune microenvironment influences the depth and duration of treatment response.

Genomic and immune signatures predict clinical outcome in newly diagnosed multiple myeloma treated with immunotherapy regimens.

Despite improving outcomes, 40% of patients with newly diagnosed multiple myeloma treated with regimens containing daratumumab, a CD38-targeted monoclonal antibody, progress prematurely. By integrating tumor whole-genome and microenvironment single-cell RNA sequencing from upfront phase 2 trials using carfilzomib, lenalidomide and dexamethasone with daratumumab ( NCT03290950 ), we show how distinct genomic drivers including high APOBEC mutational activity, IKZF3 and RPL5 deletions and 8q gain affect clinical outcomes. Furthermore, evaluation of paired bone marrow profiles, taken before and after eight cycles of carfilzomib, lenalidomide and dexamethasone with daratumumab, shows that numbers of natural killer cells before treatment, high T cell receptor diversity before treatment, the disappearance of sustained immune activation (that is, B cells and T cells) and monocyte expansion over time are all predictive of sustained minimal residual disease negativity. Overall, this study provides strong evidence of a complex interplay between tumor cells and the immune microenvironment that is predictive of clinical outcome and depth of treatment response in patients with newly diagnosed multiple myeloma treated with highly effective combinations containing anti-CD38 antibodies.