Round Table Discussion on Optimal Clinical Trial Design in Precursor Multiple Myeloma

SUMMARY

While the current approach to precursor hematologic conditions is to "watch and wait," this may change with the development of therapies that are safe and extend survival or delay the onset of symptomatic disease. The goal of future therapies in precursor hematologic conditions is to improve survival and prevent or delay the development of symptomatic disease while maximizing safety. Clinical trial considerations in this field include identifying an appropriate at-risk population, safety assessments, dose selection, primary and secondary trial endpoints including surrogate endpoints, control arms, and quality-of-life metrics, all of which may enable more precise benefit-risk assessment.

Isatuximab, carfilzomib, lenalidomide, and dexamethasone in patients with newly diagnosed, transplantation-eligible multiple myeloma (SKylaRk): a single-arm, phase 2 trial

BACKGROUND

Isatuximab is a CD38 monoclonal antibody approved for relapsed or refractory multiple myeloma. We aimed to evaluate the addition of isatuximab to weekly carfilzomib (K), lenalidomide (R), and dexamethasone (d; Isa-KRd) in transplant-eligible patients with newly diagnosed multiple myeloma and stratified maintenance by cytogenetic risk.

METHODS

This single-arm phase 2 trial was done at three cancer centres (two hospitals and a cancer institute) in Boston (MA, USA). Eligible patients were aged at least 18 years and had transplant-eligible newly diagnosed multiple myeloma and an ECOG performance status of 2 or less. Patients received four 28-day cycles of Isa-KRd, including isatuximab 10 mg/kg intravenously weekly for 8 weeks, then every other week for 16 weeks, and every 4 weeks thereafter; carfilzomib 56 mg/m2 intravenously on days 1, 8, and 15 (20 mg/m2 for cycle 1 day 1); lenalidomide 25 mg orally on days 1-21; and dexamethasone 20 mg orally the day of and day after all doses of carfilzomib and isatuximab. Consolidation involved either upfront haematopoietic stem-cell transplantation (HSCT) with two additional cycles or deferred HSCT with four additional cycles of treatment. The primary endpoint was complete response after four cycles of treatment. Analyses were by intention-to-treat. All patients who received one dose of study drug were included in the safety analyses. This study was registered at ClinicalTrials.gov, NCT04430894, and has completed enrolment.

FINDINGS

Between July 31, 2020 and Jan 31, 2022, 50 patients were enrolled. Median age was 59 years (range 40-70), 54% (27 of 50 patients) were male, and 44 (88%) were White. 46% (23 of 50) of patients had high-risk cytogenetics. Median follow-up was 26 months (IQR 20·7-30·1). 32% (16 of 50 patients) achieved a complete response after four cycles. The overall response rate (ORR) was 90% (45 patients) and 78% (39 patients) achieved a very good partial response (VGPR) or better. After completion of consolidation, 58% (29 patients) achieved a complete response; the ORR was 90% (45 patients) and 86% (43 patients) achieved a VGPR or better. The most common grade 3 or 4 side-effects (≥two patients) included neutropenia (13 [26%] of 50 patients), elevated alanine aminotransferase (six [12%] patients), fatigue (three [6%] patients), thrombocytopenia (three [6%] patients), acute kidney injury (two [4%] patients), anaemia (two [4%] patients), and febrile neutropenia (two [4%] patients). Grade 1-2 infusion-related reactions were seen in 20% (ten patients), with none grade 3. Grade 1-2 hypertension was seen in 14% (seven patients) with one grade 3 (one [2%] patient). There were two deaths assessed as unrelated to treatment.

INTERPRETATION

Although the study did not achieve the prespecified complete response threshold, Isa-KRd induced deep and durable responses in transplant-eligible patients with newly diagnosed multiple myeloma. The treatment proved safe and consistent with similar regimens in this setting.

FUNDING

Amgen, Sanofi, and Adaptive.

Long-Term Follow-Up Defines the Population That Benefits from Early Interception in a High-Risk Smoldering Multiple Myeloma Clinical Trial Using the Combination of Ixazomib, Lenalidomide, and Dexamethasone

Background

Early therapeutic intervention in high-risk SMM (HR-SMM) has demonstrated benefit in previous studies of lenalidomide with or without dexamethasone. Triplets and quadruplet studies have been examined in this same population. However, to date, none of these studies examined the impact of depth of response on long-term outcomes of participants treated with lenalidomide-based therapy, and whether the use of the 20/2/20 model or the addition of genomic alterations can further define the population that would benefit the most from early therapeutic intervention. Here, we present the results of the phase II study of the combination of ixazomib, lenalidomide, and dexamethasone in patients with HR-SMM with long-term follow-up and baseline single-cell tumor and immune sequencing that help refine the population to be treated for early intervention studies.

Methods

This is a phase II trial of ixazomib, lenalidomide, and dexamethasone (IRD) in HR-SMM. Patients received 9 cycles of induction therapy with ixazomib 4mg on days 1, 8, and 15; lenalidomide 25mg on days 1-21; and dexamethasone 40mg on days 1, 8, 15, and 22. The induction phase was followed by maintenance with ixazomib 4mg on days 1, 8, and 15; and lenalidomide 15mg d1-21 for 15 cycles for 24 months of treatment. The primary endpoint was progression-free survival after 2 years of therapy. Secondary endpoints included depth of response, biochemical progression, and correlative studies included single-cell RNA sequencing and/or whole-genome sequencing of the tumor and single-cell sequencing of immune cells at baseline.

Results

Fifty-five patients, with a median age of 64, were enrolled in the study. The overall response rate was 93%, with 31% of patients achieving a complete response and 45% achieving a very good partial response or better. The most common grade 3 or greater treatment-related hematologic toxicities were neutropenia (16 patients; 29%), leukopenia (10 patients; 18%), lymphocytopenia (8 patients; 15%), and thrombocytopenia (4 patients; 7%). Non-hematologic grade 3 or greater toxicities included hypophosphatemia (7 patients; 13%), rash (5 patients; 9%), and hypokalemia (4 patients; 7%). After a median follow-up of 50 months, the median progression-free survival (PFS) was 48.6 months (95% CI: 39.9 - not reached; NR) and median overall survival has not been reached. Patients achieving VGPR or better had a significantly better progression-free survival (p<0.001) compared to those who did not achieve VGPR (median PFS 58.2 months vs. 31.3 months). Biochemical progression preceded or was concurrent with the development of SLiM-CRAB criteria in eight patients during follow-up, indicating that biochemical progression is a meaningful endpoint that correlates with the development of end-organ damage. High-risk 20/2/20 participants had the worst PFS compared to low- and intermediate-risk participants. The use of whole genome or single-cell sequencing of tumor cells identified high-risk aberrations that were not identified by FISH alone and aided in the identification of participants at risk of progression. scRNA-seq analysis revealed a positive correlation between MHC class I expression and response to proteasome inhibition and at the same time a decreased proportion of GZMB+ T cells within the clonally expanded CD8+ T cell population correlated with suboptimal response.

Conclusions

Ixazomib, lenalidomide and dexamethasone in HR-SMM demonstrates significant clinical activity with an overall favorable safety profile. Achievement of VGPR or greater led to significant improvement in time to progression, suggesting that achieving deep response is beneficial in HR-SMM. Biochemical progression correlates with end-organ damage. Patients with high-risk FISH and lack of deep response had poor outcomes. ClinicalTrials.gov identifier: ( NCT02916771 ).

Design and Rationale of Prolonged Nightly Fasting for Multiple Myeloma Prevention (PROFAST): Protocol for a Randomized Controlled Pilot Trial

BACKGROUND

Obesity is an established, modifiable risk factor of multiple myeloma (MM); yet, no lifestyle interventions are routinely recommended for patients with overweight or obesity with MM precursor conditions. Prolonged nightly fasting is a simple, practical dietary regimen supported by research, suggesting that the synchronization of feeding-fasting timing with sleep-wake cycles favorably affects metabolic pathways implicated in MM. We describe the design and rationale of a randomized controlled pilot trial evaluating the efficacy of a regular, prolonged nighttime fasting schedule among individuals with overweight or obesity at high risk for developing MM or a related lymphoid malignancy.

OBJECTIVE

We aim to investigate the effects of 4-month prolonged nightly fasting on body composition and tumor biomarkers among individuals with overweight or obesity with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), or smoldering Waldenström macroglobulinemia (SWM).

METHODS

Individuals with MGUS, SMM, or SWM aged ≥18 years and a BMI of ≥25 kg/m2 are randomized to either a 14-hour nighttime fasting intervention or a healthy lifestyle education control group. Participants' baseline diet and lifestyle patterns are characterized through two 24-hour dietary recalls: questionnaires querying demographic, comorbidity, lifestyle, and quality-of-life information; and wrist actigraphy measurements for 7 days. Fasting intervention participants are supported through one-on-one telephone counseling by a health coach and automated SMS text messaging to support fasting goals. Primary end points of body composition, including visceral and subcutaneous fat (by dual-energy x-ray absorptiometry); bone marrow adiposity (by bone marrow histology); and tumor biomarkers, specifically M-proteins and serum free light-chain concentrations (by gel-based and serum free light-chain assays), are assessed at baseline and after the 4-month study period; changes therein from baseline are evaluated using a repeated measures mixed-effects model that accounts for the correlation between baseline and follow-up measures and is generally robust to missing data. Feasibility is assessed as participant retention (percent dropout in each arm) and percentage of days participants achieved a ≥14-hour fast.

RESULTS

The PROlonged nightly FASTing (PROFAST) study was funded in June 2022. Participant recruitment commenced in April 2023. As of July 2023, six participants consented to the study. The study is expected to be completed by April 2024, and data analysis and results are expected to be published in the first quarter of 2025.

CONCLUSIONS

PROFAST serves as an important first step in exploring the premise that prolonged nightly fasting is a strategy to control obesity and obesity-related mechanisms of myelomagenesis. In evaluating the feasibility and impact of prolonged nightly fasting on body composition, bone marrow adipose tissue, and biomarkers of tumor burden, this pilot study may generate hypotheses regarding metabolic mechanisms underlying MM development and ultimately inform clinical and public health strategies for MM prevention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05565638; http://clinicaltrials.gov/ct2/show/NCT05565638.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51368.

Management of Adverse Events Associated with Pomalidomide-Based Combinations in Patients with Relapsed/Refractory Multiple Myeloma

Multi-agent regimens incorporating immunomodulatory (IMiD®) agents such as thalidomide, lenalidomide, and pomalidomide have become the preferred standard of care for the treatment of patients with multiple myeloma (MM), resulting in improved survival outcomes. Currently, there are three IMiD agents approved for the treatment of MM: thalidomide, lenalidomide, and pomalidomide. Lenalidomide is commonly used to treat patients with newly diagnosed MM and as maintenance therapy following stem cell transplant or after disease relapse. Pomalidomide, the focus of this review, is approved in patients with relapsed/refractory MM (RRMM). Despite survival benefits, IMiD agents each have different safety profiles requiring consideration both prior to starting therapy and during treatment. Adverse event (AE) management is essential, not only to ensure treatment adherence and thus ensure optimal efficacy but also to maintain patient quality of life. Here, we discuss AEs associated with pomalidomide and present five clinically relevant hypothetical case studies in patients with RRMM to provide scenario-driven guidance regarding treatment selection and AE prevention and management in the clinical setting. Lastly, as new treatment approaches continue to be explored in MM, we also discuss novel cereblon E3 ligase modulator (CELMoD™) agents including iberdomide (CC-220) and mezigdomide (CC-92480).

Racial and ethnic differences in clinical outcomes among patients with multiple myeloma treated with CAR T-cell therapy

ABSTRACT

Idecabtagene vicleucel (ide-cel) was the first chimeric antigen receptor T-cell therapy to gain US Food and Drug Administration approval for patients with relapsed/refractory multiple myeloma (RRMM). The clinical outcomes of standard of care (SOC) ide-cel in racially and ethnically diverse populations have been understudied. This study pooled data from 207 patients with RRMM (28% patients of racial and ethnic minority groups) treated with SOC ide-cel across 11 institutions to examine racial and ethnic differences in the incidence of toxicities and adverse events, response to ide-cel, and survival. This study included 22 (11%) Hispanic, 36 (17%) non-Hispanic Black, and 149 (72%) non-Hispanic White patients with RRMM. Compared with Hispanic and non-Hispanic White patients, non-Hispanic Black patients had higher median levels of C-reactive protein (1.0, 0.8, and 3.5 mg/dL, respectively; P = .02) and baseline ferritin (362.0 vs 307.0 vs 680.5, respectively; P = .08) and were more likely to develop cytokine release syndrome (77%, 85%, and 97%, respectively; P = .04). Although best overall response rate was lower among Hispanic patients (59%) than among non-Hispanic Black (86%) and White patients (86%; P = .01), there were no racial and ethnic differences in progression-free or overall survival. We provide, to our knowledge, the first and largest investigation of clinical outcomes of SOC ide-cel by race and ethnicity. Despite differences in safety and response to ide-cel, our findings encourage the use of ide-cel in all patients with RRMM. These findings should be confirmed in larger samples of diverse patients with RRMM, with longer follow-up time.

Clinical Outcomes of Monoclonal Gammopathy of Renal Significance Without Detectable Clones

Introduction

Monoclonal gammopathy of renal significance (MGRS) is characterized by monoclonal immunoglobulin deposition in kidneys. However, monoclonal immunoglobulin and responsible clone(s) are not always detectable. Treatment response and kidney outcome of MGRS without detectable clones remain unclear.

Methods

In this single-center, retrospective cohort study, we identified MGRS without detectable clones from our biopsy repository between 2010 and 2022. We investigated the correlations between treatment regimens and kidney outcomes defined by proteinuria and estimated glomerular filtration rate (eGFR), and the impact of repeat kidney biopsy.

Results

Our study cohort included 29 cases (27 native kidney and 2 transplant allograft biopsies) of MGRS without detectable clones. At diagnosis, median serum creatinine was 1.8 mg/dl (interquartile range [IQR] 1.3-2.7), with proteinuria 4.6 g/gCr (IQR 2.3-7.9). Treatment regimens were variable: 6 (21%) received conservative therapy, 13 (45%) received plasma cell clone-directed therapy, 8 (28%) received lymphocytic clone-directed therapy, and 2 (7%) received nonclone-directed immunosuppressive therapy. Of 24 patients with proteinuria >0.5 g/gCr at diagnosis, 9 (38%) and 6 (25%) achieved complete response (CR) and partial response (PR), respectively. If interstitial fibrosis and tubular atrophy (IFTA) was >50% at the initial biopsy, less proportion of patients achieved CR. Six of 7 repeat biopsies showed progression of chronic changes (e.g., IFTA) but provided limited information on treatment response.

Conclusion

Treatment regimens and outcomes of MGRS without detectable clones were extremely variable. Repeat biopsy provided limited information to assess disease activity or the need for additional treatment. More sensitive tools are needed to detect clones and to assess treatment response.

Characterizing dry mass and volume changes in human multiple myeloma cells upon treatment with proteotoxic and genotoxic drugs

Multiple myeloma (MM) is a cancer of terminally differentiated plasma cells. MM remains incurable, but overall survival of patients has progressively increased over the past two decades largely due to novel agents such as proteasome inhibitors (PI) and the immunomodulatory agents. While these therapies are highly effective, MM patients can be de novo resistant and acquired resistance with prolonged treatment is inevitable. There is growing interest in early, accurate identification of responsive versus non-responsive patients; however, limited sample availability and need for rapid assays are limiting factors. Here, we test dry mass and volume as label-free biomarkers to monitor early response of MM cells to treatment with bortezomib, doxorubicin, and ultraviolet light. For the dry mass measurement, we use two types of phase-sensitive optical microscopy techniques: digital holographic tomography and computationally enhanced quantitative phase microscopy. We show that human MM cell lines (RPMI8226, MM.1S, KMS20, and AMO1) increase dry mass upon bortezomib treatment. This dry mass increase after bortezomib treatment occurs as early as 1 h for sensitive cells and 4 h for all tested cells. We further confirm this observation using primary multiple myeloma cells derived from patients and show that a correlation exists between increase in dry mass and sensitivity to bortezomib, supporting the use of dry mass as a biomarker. The volume measurement using Coulter counter shows a more complex behavior; RPMI8226 cells increase the volume at an early stage of apoptosis, but MM.1S cells show the volume decrease typically observed with apoptotic cells. Altogether, this cell study presents complex kinetics of dry mass and volume at an early stage of apoptosis, which may serve as a basis for the detection and treatment of MM cells.

Respiratory infections predominate after day 100 following B-cell maturation antigen-directed CAR T-cell therapy

Infections are an important complication after B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapy and risks may differ between the early and late periods. We evaluated infections in 99 adults who received a first BCMA-directed CAR T-cell therapy (commercial and investigational autologous BCMA CAR T-cell products at the recommended phase 2 dose) for relapsed/refractory multiple myeloma between November 2016 and May 2022. Infections were recorded until day 365, if patients experienced symptoms with a microbiologic diagnosis, or for symptomatic site-specific infections treated with antimicrobials. One-year cumulative incidence functions were calculated based on time to first respiratory infection using dates of infection-free death and receipt of additional antineoplastic therapies as competing risks. Secondary analysis evaluated risk factors for late respiratory infections using univariate and multivariable Cox regression models. Thirty-seven patients (37%) experienced 64 infectious events over the first year after BCMA-directed CAR T-cell therapy, with 42 early infectious events (days, 0-100), and 22 late infectious events (days, 101-365). Respiratory infections were the most common site-specific infection and the relative proportion of respiratory infections increased in the late period (31% of early events vs 77% of late events). On multivariable analysis, hypogammaglobulinemia (hazard ratio [HR], 6.06; P = .044) and diagnosis of an early respiratory viral infection (HR, 2.95; P = .048) were independent risk factors for late respiratory infection. Respiratory infections predominate after BCMA CAR T-cell therapy, particularly after day 100. Hypogammaglobulinemia and diagnosis of an early respiratory infection are risk factors for late respiratory infections that may be used to guide targeted preventive strategies.

Real-world experience of patients with multiple myeloma receiving ide-cel after a prior BCMA-targeted therapy

Most patients with multiple myeloma experience disease relapse after treatment with a B-cell maturation antigen-targeted therapy (BCMA-TT), and data describing outcomes for patients treated with sequential BCMA-TT are limited. We analyzed clinical outcomes for patients infused with standard-of-care idecabtagene vicleucel, an anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, at 11 US medical centers. A total of 50 patients with prior BCMA-TT exposure (38 antibody-drug conjugate, 7 bispecific, 5 CAR T) and 153 patients with no prior BCMA-TT were infused with ide-cel, with a median follow-up duration of 4.5 and 6.0 months, respectively. Safety outcomes between cohorts were comparable. The prior BCMA-TT cohort had a lower overall response rate (74% versus 88%; p = 0.021), median duration of response (7.4 versus 9.6 months; p = 0.03), and median progression-free survival (3.2 months versus 9.0 months; p = 0.0002) compared to the cohort without prior BCMA-TT. All five patients who received a prior anti-BCMA CAR T responded to ide-cel, and survival outcomes were best for this subgroup. In conclusion, treatment with ide-cel yielded meaningful clinical responses in real-world patients exposed to a prior BCMA-TT, though response rates and durability were suboptimal compared to those not treated with a prior BCMA-TT.

Selinexor: Targeting a novel pathway in multiple myeloma

Selinexor is an orally bioavailable selective inhibitor of nuclear export compound that inhibits exportin-1 (XPO1), a novel therapeutic target that is overexpressed in multiple myeloma (MM) and is responsible for the transport of ∼220 nuclear proteins to the cytoplasm, including tumour suppressor proteins. Inhibition of this process has demonstrated substantial antimyeloma activity in preclinical studies, both alone and in combination with established MM therapeutics. Based on a clinical trial programme encompassing multiple combination regimens, selinexor-based therapy has been approved for the treatment of relapsed/refractory MM (RRMM), with selinexor-dexamethasone approved in the later-relapse setting for penta-refractory patients and selinexor-bortezomib-dexamethasone approved for patients who have received ≥1 prior therapy. Here, we provide a comprehensive review of the clinical data on selinexor-based regimens, including recent updates from the 2022 American Society of Hematology annual meeting, and summarise ongoing studies of this novel targeted agent in newly diagnosed MM and RRMM.

Bispecific Monoclonal Antibodies in Multiple Myeloma: Data from ASH 2022: A Podcast

The introduction of novel immunotherapies has transformed the treatment landscape in multiple myeloma (MM). The addition of these agents has significantly improved patient outcomes; however, MM remains largely incurable, with heavily pretreated patients suffering from shorter survival times. To address this unmet need, the focus has shifted toward novel mode of action therapies, such as bispecific antibodies (BsAb), which simultaneously bind to immune effector cells and myeloma cells. Currently, there are several T cell-redirecting BsAb being developed that target BCMA, GPRC5D, and FcRH5. These BsAb show impressive clinical activity for the relapsed/refractory population targeted and will likely become an essential part of MM treatment protocols in the future. In this podcast, the authors summarize and highlight some of the T cell-redirecting BsAb currently in development for the treatment of relapsed/refractory MM with a focus on the data reported at the oral session for BsAb at the American Society of Hematology's 2022 meeting from clinical phase 1 and 2 studies. The six presentations reported the latest safety and efficacy data for the BsAb: talquetamab, elranatamab, teclistamab, forimtamig, and alnuctamab.

A safety review of recently approved and emerging drugs for patients with relapsed or refractory multiple myeloma

INTRODUCTION

Multiple new drugs have been approved over the past 5 years for the treatment of relapsed/refractory multiple myeloma (RRMM), and these are being increasingly widely used. Clinicians need to familiarize themselves with common toxicities associated with these drugs and with novel toxicities requiring specific management and supportive care.

AREAS COVERED

We review common toxicities associated with agents approved for RRMM in the past 5 years, including the anti-CD38 monoclonal antibody isatuximab, the antibody-drug conjugate belantamab mafodotin, the bispecific antibody teclistamab, the chimeric antigen receptor (CAR) T cell products idecabtagene vicleucel and ciltacabtagene autoleucel, the selective inhibitor of nuclear export compound selinexor, and the drug-peptide conjugate melflufen, as well as toxicities associated with emerging agents for RRMM including additional bispecific antibodies, the BCL-2 inhibitor venetoclax, and the cereblon E3 ligase modulators iberdomide and mezigdomide. We searched the published literature using PubMed, plus congress abstracts, for the above list of drug names or classes and 'myeloma.'

EXPERT OPINION

Optimal management of toxicities associated with these recently approved and emerging therapies will be critical in maximizing clinical benefit and aiding widespread adoption in routine clinical practice. We summarize current recommendations and guidelines and provide expert insights into supportive care requirements.

Updates in Plasma Cell Dyscrasias and Related Monoclonal Immunoglobulin-Mediated Renal Disease

Pathogenic roles of monoclonal immunoglobulins in kidney disease have been attributed previously to malignant plasma cell and lymphoproliferative disorders such as multiple myeloma, lymphoplasmacytic lymphoma, chronic lymphocytic leukemia, or amyloid light chain amyloidosis. Improved technology, advancements in molecular diagnostics, and highly sensitive imaging techniques have established the need to redefine monoclonal gammopathies and the kidney disorders that are associated with monoclonal immunoglobulins regardless of tumor burden. This has led to the establishment of monoclonal gammopathy with renal significance (MGRS). MGRS was defined by the International Kidney and Monoclonal Gammopathy Research Group in 2012 as a clonal proliferative disorder that produces a nephrotoxic monoclonal immunoglobulin and does not meet previously defined hematological criteria for treatment of a specific malignancy. MGRS encompasses a wide array of pathologies with knowledge surrounding its incidence, prognosis, and management continuously increasing. This review examines the current evidence on the diagnosis, prognosis, pathogenesis, and therapy of plasma cell dyscrasias and related MGRS.

Personalised progression prediction in patients with monoclonal gammopathy of undetermined significance or smouldering multiple myeloma (PANGEA): a retrospective, multicohort study

BACKGROUND

Patients with precursors to multiple myeloma are dichotomised as having monoclonal gammopathy of undetermined significance or smouldering multiple myeloma on the basis of monoclonal protein concentrations or bone marrow plasma cell percentage. Current risk stratifications use laboratory measurements at diagnosis and do not incorporate time-varying biomarkers. Our goal was to develop a monoclonal gammopathy of undetermined significance and smouldering multiple myeloma stratification algorithm that utilised accessible, time-varying biomarkers to model risk of progression to multiple myeloma.

METHODS

In this retrospective, multicohort study, we included patients who were 18 years or older with monoclonal gammopathy of undetermined significance or smouldering multiple myeloma. We evaluated several modelling approaches for predicting disease progression to multiple myeloma using a training cohort (with patients at Dana-Farber Cancer Institute, Boston, MA, USA; annotated from Nov, 13, 2019, to April, 13, 2022). We created the PANGEA models, which used data on biomarkers (monoclonal protein concentration, free light chain ratio, age, creatinine concentration, and bone marrow plasma cell percentage) and haemoglobin trajectories from medical records to predict progression from precursor disease to multiple myeloma. The models were validated in two independent validation cohorts from National and Kapodistrian University of Athens (Athens, Greece; from Jan 26, 2020, to Feb 7, 2022; validation cohort 1), University College London (London, UK; from June 9, 2020, to April 10, 2022; validation cohort 1), and Registry of Monoclonal Gammopathies (Czech Republic, Czech Republic; Jan 5, 2004, to March 10, 2022; validation cohort 2). We compared the PANGEA models (with bone marrow [BM] data and without bone marrow [no BM] data) to current criteria (International Myeloma Working Group [IMWG] monoclonal gammopathy of undetermined significance and 20/2/20 smouldering multiple myeloma risk criteria).

FINDINGS

We included 6441 patients, 4931 (77%) with monoclonal gammopathy of undetermined significance and 1510 (23%) with smouldering multiple myeloma. 3430 (53%) of 6441 participants were female. The PANGEA model (BM) improved prediction of progression from smouldering multiple myeloma to multiple myeloma compared with the 20/2/20 model, with a C-statistic increase from 0·533 (0·480-0·709) to 0·756 (0·629-0·785) at patient visit 1 to the clinic, 0·613 (0·504-0·704) to 0·720 (0·592-0·775) at visit 2, and 0·637 (0·386-0·841) to 0·756 (0·547-0·830) at visit three in validation cohort 1. The PANGEA model (no BM) improved prediction of smouldering multiple myeloma progression to multiple myeloma compared with the 20/2/20 model with a C-statistic increase from 0·534 (0·501-0·672) to 0·692 (0·614-0·736) at visit 1, 0·573 (0·518-0·647) to 0·693 (0·605-0·734) at visit 2, and 0·560 (0·497-0·645) to 0·692 (0·570-0·708) at visit 3 in validation cohort 1. The PANGEA models improved prediction of monoclonal gammopathy of undetermined significance progression to multiple myeloma compared with the IMWG rolling model at visit 1 in validation cohort 2, with C-statistics increases from 0·640 (0·518-0·718) to 0·729 (0·643-0·941) for the PANGEA model (BM) and 0·670 (0·523-0·729) to 0·879 (0·586-0·938) for the PANGEA model (no BM).

INTERPRETATION

Use of the PANGEA models in clinical practice will allow patients with precursor disease to receive more accurate measures of their risk of progression to multiple myeloma, thus prompting for more appropriate treatment strategies.

FUNDING

SU2C Dream Team and Cancer Research UK.

MinimuMM-seq: Genome Sequencing of Circulating Tumor Cells for Minimally Invasive Molecular Characterization of Multiple Myeloma Pathology

Multiple myeloma (MM) develops from well-defined precursor stages; however, invasive bone marrow (BM) biopsy limits screening and monitoring strategies for patients. We enumerated circulating tumor cells (CTC) from 261 patients (84 monoclonal gammopathy of undetermined significance, 155 smoldering multiple myeloma, and 22 MM), with neoplastic cells detected in 84%. We developed a novel approach, MinimuMM-seq, which enables the detection of translocations and copy-number abnormalities through whole-genome sequencing of highly pure CTCs. Application to CTCs in a cohort of 51 patients, 24 with paired BM, was able to detect 100% of clinically reported BM biopsy events and could replace molecular cytogenetics for diagnostic yield and risk classification. Longitudinal sampling of CTCs in 8 patients revealed major clones could be tracked in the blood, with clonal evolution and shifting dynamics of subclones over time. Our findings provide proof of concept that CTC detection and genomic profiling could be used clinically for monitoring and managing disease in MM.

SIGNIFICANCE

In this study, we established an approach enabling the enumeration and sequencing of CTCs to replace standard molecular cytogenetics. CTCs harbored the same pathognomonic MM abnormalities as BM plasma cells. Longitudinal sampling of serial CTCs was able to track clonal dynamics over time and detect the emergence of high-risk genetic subclones. This article is highlighted in the In This Issue feature, p. 247.

Immune biomarkers of response to immunotherapy in patients with high-risk smoldering myeloma

Patients with smoldering multiple myeloma (SMM) are observed until progression, but early treatment may improve outcomes. We conducted a phase II trial of elotuzumab, lenalidomide, and dexamethasone (EloLenDex) in patients with high-risk SMM and performed single-cell RNA and T cell receptor (TCR) sequencing on 149 bone marrow (BM) and peripheral blood (PB) samples from patients and healthy donors (HDs). We find that early treatment with EloLenDex is safe and effective and provide a comprehensive characterization of alterations in immune cell composition and TCR repertoire diversity in patients. We show that the similarity of a patient's immune cell composition to that of HDs may have prognostic relevance at diagnosis and after treatment and that the abundance of granzyme K (GZMK)+ CD8+ effector memory T (TEM) cells may be associated with treatment response. Last, we uncover similarities between immune alterations observed in the BM and PB, suggesting that PB-based immune profiling may have diagnostic and prognostic utility.

Melphalan flufenamide for relapsed/refractory multiple myeloma

Despite therapeutic advances and improved patient outcomes in recent years, multiple myeloma (MM) remains a mostly incurable hematologic malignancy. Patients with relapsed/refractory MM (RRMM), especially those with triple-class-refractory disease or poor-prognostic features, have substantially unmet needs for new therapies with novel mechanisms of action. Melphalan flufenamide (melflufen) is the first alkylating peptide-drug conjugate that targets aminopeptidases to show efficacy and manageable safety, in combination with dexamethasone, in patients with RRMM who had received at least 4 prior lines of therapy, including at least 1 immunomodulatory drug, at least 1 proteasome inhibitor and at least 1 anti-CD38 monoclonal antibody, and received accelerated approval by the U.S. Food and Drug Administration (FDA) in early 2021 for use in this patient population. Initial analyses of the phase III OCEAN study data led to melflufen being voluntarily withdrawn from the U.S. market in late 2021, but subsequent analyses have prompted the manufacturer to rescind its voluntary withdrawal to allow further discussions with the U.S. FDA and the regulatory review with the European Medicines Agency (EMA) is also ongoing. Here, we provide a review of the novel mechanism of action and pharmacokinetics of melflufen, as well as key efficacy and safety from clinical studies that supported its initial approval, and discuss the nuances of the OCEAN study data. Melflufen demonstrates the potential of novel peptide-drug conjugates to positively impact the treatment landscape in RRMM.

Triplet Therapy, Transplantation, and Maintenance until Progression in Myeloma

BACKGROUND

In patients with newly diagnosed multiple myeloma, the effect of adding autologous stem-cell transplantation (ASCT) to triplet therapy (lenalidomide, bortezomib, and dexamethasone [RVD]), followed by lenalidomide maintenance therapy until disease progression, is unknown.

METHODS

In this phase 3 trial, adults (18 to 65 years of age) with symptomatic myeloma received one cycle of RVD. We randomly assigned these patients, in a 1:1 ratio, to receive two additional RVD cycles plus stem-cell mobilization, followed by either five additional RVD cycles (the RVD-alone group) or high-dose melphalan plus ASCT followed by two additional RVD cycles (the transplantation group). Both groups received lenalidomide until disease progression, unacceptable side effects, or both. The primary end point was progression-free survival.

RESULTS

Among 357 patients in the RVD-alone group and 365 in the transplantation group, at a median follow-up of 76.0 months, 328 events of disease progression or death occurred; the risk was 53% higher in the RVD-alone group than in the transplantation group (hazard ratio, 1.53; 95% confidence interval [CI], 1.23 to 1.91; P<0.001); median progression-free survival was 46.2 months and 67.5 months. The percentage of patients with a partial response or better was 95.0% in the RVD-alone group and 97.5% in the transplantation group (P = 0.55); 42.0% and 46.8%, respectively, had a complete response or better (P = 0.99). Treatment-related adverse events of grade 3 or higher occurred in 78.2% and 94.2%, respectively; 5-year survival was 79.2% and 80.7% (hazard ratio for death, 1.10; 95% CI, 0.73 to 1.65).

CONCLUSIONS

Among adults with multiple myeloma, RVD plus ASCT was associated with longer progression-free survival than RVD alone. No overall survival benefit was observed. (Funded by the National Heart, Lung, and Blood Institute and others; DETERMINATION ClinicalTrials.gov number, NCT01208662.).

Melflufen for the treatment of multiple myeloma

INTRODUCTION

Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that takes advantage of increased aminopeptidase activity inside tumor cells to rapidly release alkylating agents therein. Melflufen in combination with dexamethasone has been evaluated in multiple clinical trials in patients with relapsed/refractory multiple myeloma (MM).

AREAS COVERED

This profile covers the unique mechanism of action of melflufen, the preclinical results supporting its activity in cellular models of resistance to chemotherapy, its activity in animal models of MM, and the clinical pharmacokinetics of melflufen. Findings from clinical trials evaluating melflufen, including the pivotal phase II HORIZON study and the phase III OCEAN study, are discussed.

EXPERT OPINION

Although MM treatment has improved, patients with disease refractory to multiple standard-of-care drug classes face a dismal prognosis. Melflufen demonstrated efficacy and tolerability in select populations, with an initial approval in the United States in patients with ≥ four previous lines of therapy and triple-class-refractory MM. Results from the phase III OCEAN study - currently under discussion with regulatory agencies in the United States and Europe - are more complex and have been put into context herein. Lastly, melflufen provides a proof-of-concept for the utility of the peptide-drug conjugate platform in relapsed/refractory MM.

Abstract 2074: ORIC-533, a small molecule CD73 inhibitor with best-in-class properties, reversesimmunosuppression and has potential as an immunomodulatory therapy in patients with multiple myeloma

Adenosine accumulation within the tumor microenvironment can severely limit antitumor immunity by promoting the expansion of immunosuppressive cell types and impairing immune cell function, including T cells, natural killer cells and dendritic cells. The generation of adenosine from adenosine monophosphate (AMP) requires the activity of a cell surface ecto-5’-nucleotidase, CD73, expressed on the surface of various cell types including immune cells. CD73 overexpression is observed in many tumor types and correlates with unfavorable clinical outcomes. Given the essential role of CD73 in generating adenosine, inhibition of CD73 is a promising therapeutic strategy. Recent clinical proof of concept data demonstrated a significant improvement in progression free survival for non-small cell lung cancer patients upon targeting CD73 with the oleclumab anti-CD73 antibody in combination with anti-PDL1, relative to anti-PDL1 checkpoint inhibitor treatment alone.We developed ORIC-533, a potent, orally bioavailable, AMP-competitive, small molecule inhibitor of CD73, that is highly selective for CD73 and exhibits picomolar potency in biochemical assays, completely blocking adenosine production from AMP. In ex vivo assays, ORIC-533 displayed greater potency in restoring immunosuppressed CD8+ T cell proliferation and activation compared to oleclumab, as well as greater potency versus small molecule inhibitors of CD73 and the adenosine receptor. In multiple myeloma (MM) patients, elevated adenosine levels in the bone marrow (BM) niche correlate with progression of multiple myeloma through a CD73-mediated pathway. Moreover, we recently reported a functional role of CD73 signaling in BM of MM patients, indicating that CD73 inhibition may represent a unique vulnerability and treatment strategy for MM (Ray et al., abstract #2675, ASH 2021).

We tested the impact of CD73 inhibition in bone marrow aspirates from patients with relapsed or refractory MM, using an autologous ex vivo assay system comprised of the multiple myeloma BM microenvironment. CD73 inhibition stimulated the activation of plasmacytoid dendritic cells and T cell activation in the context of the MM BM milieu. Moreover, ORIC CD73 inhibitor as a single agent overcame immune suppression and triggered significant lysis and cell death of multiple myeloma cells by autologous T-cells in the bone marrow microenvironment. Taken together, these results demonstrate that the ORIC CD73 inhibitor potently inhibits the adenosine pathway, which restores anti-tumor immunity and therefore holds potential for patients with MM. Based upon these data, ORIC-533 is being studied as a single agent in a Phase 1 clinical trial in patients with relapsed or refractory multiple myeloma.

Citation Format: Melissa R. Junttila, Arghya Ray, Robert Warne, Xi Chen, Ting Du, Dena Sutimantanapi, Jae H. Chang, Brian Blank, Jared Moore, Chudi O. Ndubaku, Tatiana Zavorotinskaya, Pratik Multani, Omar Nadeem, Dharminder Chauhan, Kenneth C. Anderson, Lori S. Friedman. ORIC-533, a small molecule CD73 inhibitor with best-in-class properties, reversesimmunosuppression and has potential as an immunomodulatory therapy in patients with multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2074.

B-PRISM (Precision Intervention Smoldering Myeloma): A phase II trial of combination of daratumumab, bortezomib, lenalidomide, and dexamethasone in high-risk smoldering multiple myeloma

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Background: Early therapeutic intervention with lenalidomide has shown to be effective in delaying progression in patients with high-risk smoldering multiple myeloma (HR-SMM) (Lonial J Clin Oncol 2020). Quadruplet regimen of daratumumab, bortezomib, lenalidomide and dexamethasone (D-RVD) has demonstrated significant activity in multiple myeloma, achieving high rates of minimal residual disease (MRD) negativity (Voorhees Blood 2020). Thus, we proposed to examine the activity and safety of D-RVD in patients with HR-SMM. Methods: This is a phase II single center, single-arm, open label study evaluating the combination of D-RVD in HR-SMM. Eligibility included high risk per Mayo 2018 “20-2-20” model and other previously established criteria including Mayo 2008 criteria, presence of immunoparesis, evolving type of SMM, and high risk FISH. Primary objective is rate of sustained MRD negativity at 2 years. Secondary objectives include PFS, response rates and safety. Treatment duration with modified D-RVD is for total of 2 years (24 cycles). Daratumumab is administered subcutaneously (SQ) per standard dose and schedule, bortezomib given weekly on days 1, 8, 15 for cycles 1-6 and then biweekly until completion of cycle 24. Lenalidomide is administered on days 1-21 and dexamethasone is administered weekly. All eligible patients will undergo stem cell collection after 6 cycles of therapy. Results: At the time of data cut off, 20 patients have been enrolled with a median follow up of 6 months. The median age is 58 years old (range 40-73). Sixteen out of 20 (80%) patients met high risk criteria per Mayo 2018 model with median plasmacytosis of 20%, median M protein value of 2.6 g/dl and median FLC ratio of 28.2. Seven patients had high-risk FISH: 5 with 1q duplication, 2 with t(4;14). Most common toxicities of any grade included neutropenia (65%), WBC decreased (55%) insomnia (50%), constipation (45%) and hypophosphatemia (45%). Most common grade 3 toxicities included neutropenia (15%), ALT increased (5%), thrombocytopenia (5%), hyperglycemia (5%), hypertension (5%), diarrhea (5%), syncope (5%). No patients discontinued therapy due to toxicity. The overall response rate is 90% with 40% PR, 25% VGPR and 25% CR. All patients have achieved at least a MR and 50% achieved VGPR or greater with responses deepening over time. No patients have progressed on treatment. MRD was evaluable in 16 patients and 8 patients have undergone MRD testing, with MRD negativity rate of 50% (4/8) and 25% (2/8) at thresholds of 10-5 and 10-6, respectively. Stem cells were successfully collected in all patients with mean stem cell yield of 5.78 x 106 CD34+/kg cells. Conclusions: D-RVD is well tolerated in patients with HR-SMM demonstrating significant early activity. Responses continue to deepen over time with patients achieving MRD negative disease. Clinical trial information: NCT04775550.

A phase II study of daratumumab with weekly carfilzomib, pomalidomide, and dexamethasone in relapsed and refractory multiple myeloma

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Background: Daratumumab (dara), carfilzomib (K), pomalidomide (P), and dexamethasone (d) are established in relapsed multiple myeloma (MM) with activity in 3-drug combinations including: dara Kd; dara Pd; and KPd. The paradigm in relapsed/refractory disease is moving towards more intensive and well-tolerated combinations to achieve deeper and more durable responses while ensuring tolerability. Quadruplet regimens are now becoming standard in newly diagnosed MM, and we explored a 4-drug regimen in relapsed disease. Preliminary results of a phase 2 study of dara KPd with a twice/week schedule of K showed an ORR of 86% in pts with a median of 1 prior line (Jasielec et al., ASH 2020). Here we report an ongoing study of dara with weekly KPd (dara wKPd) to improve the accessibility of this regimen. Methods: This phase 2 study (NCT04176718) will enroll up to 43 pts with relapsed/refractory MM who have received at least 1 prior therapy, including both lenalidomide and a proteasome inhibitor. Prior therapy with dara, K, or P was permitted except for K and P given together as last line of therapy. Dara wKPd was given on a 28-day schedule. Dara was given according to the dara Pd schedule. An initial cohort received dara 16 mg/kg iv (with first dose split over two days); the trial was amended to dara 1800 mg sc. K 56 mg/m2 iv was given weekly on days 1, 8, 15; for C1D1, dose was 20 mg/m2. P 4 mg was given po on days 1-21. Dex 40 mg was given weekly with the dose split over two days. Treatment was until progression or unacceptable toxicity. The primary endpoints are overall response and the safety profile of dara wKPd. Secondary endpoints include PFS. Results: At time of data cutoff, 24 pts were enrolled; median age was 65 (range 42-73), and median number of prior regimens was 2 (range 1-3). All pts were refractory to their last line of therapy and had prior lenalidomide and bortezomib. Additional prior therapies included: pomalidomide (54%), carfilzomib (13%), ixazomib (46%), cyclophosphamide (4%), auto SCT (29%). High risk FISH was present (out of 24 pts): del 17p (13%); t(14;16) (8%); gain of 1q (46%). Median follow up was 8.4 months. 2 pts came off study due to neutropenia leading to delay in treatment. Grade 3-4 hematologic AEs included neutropenia (46%) and thrombocytopenia (25%). There was 1 episode of febrile neutropenia. Common non hematologic AEs (all; grade 3-4) included fatigue (42%; 0%); dyspnea (38%; 4%); increase in ALT/AST (29%; 8%); insomnia (21%; 0%); neuropathy (17%; 0%). 22 pts were evaluable for response, with an overall response rate of 95% (PR 23%, VPGR 68%, CR 5%). Median PFS at 12 months was 86.2% (95% CI, 70%-100%). Conclusions: Dara wKPd shows some of the highest response rates (95%) reported to date in relapsed/refractory MM. This likely reflects the incorporation of 4 active drugs in 1 regimen and builds on the efficacy of dara-based triplet regimens, with manageable toxicity and convenience of weekly K. Clinical trial information: NCT04176718.

Quality of life, psychological distress, and prognostic perceptions in patients with multiple myeloma

BACKGROUND

Multiple myeloma (MM) is an incurable hematologic malignancy requiring long-term, continuous therapy. Despite its chronic and unrelenting course, studies examining quality of life (QOL), psychological distress, and perceptions of prognosis by line of therapy are lacking.

METHODS

The authors conducted a cross-sectional, multisite study of patients undergoing treatment for MM (excluding maintenance) between June 2020 and January 2021. The authors conducted purposeful sampling and recruited patients to 3 cohorts based on lines of therapy: 1) newly diagnosed receiving first-line therapy; 2) 2 to 3 lines; and 3) 4 or more lines. Patients completed validated questionnaires to assess their QOL, fatigue, psychological distress, and perceptions of prognosis.

RESULTS

A total of 180 patients with MM were enrolled (newly diagnosed [n = 60], 2 to 3 lines [n = 60], and ≥4 lines of therapy [n = 60]). QOL, symptom burden, and fatigue scores did not differ by lines of therapy. There were no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms were 23.9% (43 of 180), 23.9% (43 of 180), and 24.4% (44 of 180), respectively. Most patients (84.7%, 149 of 176) reported that their oncologist told them their cancer was incurable, but only 30.6% (53 of 173) acknowledged that they were terminally ill, and 42.0% (73 of 174) reported that they thought their cancer was incurable.

CONCLUSIONS

Patients with MM undergoing treatment experience impaired QOL and elevated psychological distress across the disease continuum, regardless of line of therapy. A substantial proportion of patients with MM have significant misperceptions about their prognosis and the curability of their illness despite reporting being informed of the prognosis by their oncologist.

LAY SUMMARY

This study discusses 180 patients with MM (newly diagnosed [n = 60], 2-3 lines [n = 60], and ≥4 lines of therapy [n = 60]). Quality of life, symptom burden, and fatigue scores do not differ by lines of therapy. There are also no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms are 23.9%, 23.9%, and 24.4%, respectively. Most patients (84.7%) report that their oncologist told them their cancer was incurable, but only 30.6% acknowledge that they are terminally ill, and 42.0% report that they thought their cancer was incurable.

Digital Health for Patients With Multiple Myeloma: An Unmet Need

Multiple myeloma (MM) is associated with the highest symptom burden and lowest health-related quality of life (HRQoL) among patients with hematologic malignancies. HRQoL in MM is heterogeneous, varying over the course of disease, with the highest burden at diagnosis and relapse. Patients with MM are increasingly being treated with oral maintenance medications at home. As a result, longitudinal monitoring of medication adherence and patient-reported outcomes, including HRQoL, could inform on disease status, therapeutic tolerability, and satisfaction with care. Digital health technologies, including telemedicine, mobile health, and wearable devices, are poised to become an integral part of modern health care, in part due to the surge in telemedicine necessitated by the COVID-19 pandemic. Although the literature has many reports on the use of digital health technologies in other types of cancers, fewer studies report on their application to MM. In the current narrative review, we survey the applications of digital health for MM. Although there is evidence that some are associated with improved health outcomes, challenges exist that must be met to ensure more widespread adoption. These include the need for increased awareness by patients and health care providers, lack of access by the typical older patient with MM, absence of randomized clinical trials, and low integration with current workflows such as electronic health records. Following our summary of technologies that could benefit patients with MM, we end by describing our vision for how they can be integrated into each phase of the patient journey.

Patient-reported outcomes in relapsed/refractory multiple myeloma treated with melflufen plus dexamethasone: analyses from the Phase II HORIZON study

Relapsed/refractory multiple myeloma (RRMM) is known to have a high burden of disease and complications associated with refractoriness to prior lines of therapy. Severe pain and fatigue symptoms and impairments in physical and emotional functioning have been strongly linked to reduced health‐related quality of life (HRQoL) in patients with RRMM. Assessment of patient reported‐outcome measures from the pivotal, Phase II HORIZON study (OP‐106; NCT02963493) in patients with RRMM (n = 64) demonstrated that melphalan flufenamide (melflufen) plus dexamethasone treatment preserved HRQoL. Patients had clinically meaningful improvements, even after eight treatment cycles, in relevant scales such as global health status/QoL, physical functioning, emotional functioning, pain, and fatigue. Patients with triple‐class–refractory disease (n = 50) displayed similar improvements. Patient‐reported outcome deterioration was delayed for a substantial amount of time in patients who experienced a response to melflufen plus dexamethasone treatment relative to patients who did not experience a response. These findings support the notion that treatment with melflufen plus dexamethasone may sustain or improve HRQoL over time in patients with RRMM, including in patients with triple‐class–refractory disease for whom outcomes are generally worse. The clinical benefits observed in patients from the HORIZON trial are encouraging and supportive of translation into real‐world practice.

Finding the optimal partner to pair with bispecific antibody therapy for multiple myeloma

BCMA/CD3ε-targeted bispecific antibody (BsAb) therapy represents a promising T-cell redirecting immunotherapy to treat relapsed and refractory multiple myeloma (MM). However, rational combination strategies will most likely be key to achieve a long-lasting immune response. In this issue, Meermeier and colleagues investigate BsAb therapy in a syngeneic MM model and elucidate that partnering with cyclophosphamide is associated with tempered activation, mitigated exhaustion of T-cells, and is superior to pomalidomide or bortezomib in enhancing durable anti-MM efficacy.

Melflufen plus dexamethasone (dex) in patients (pts) with relapsed/refractory multiple myeloma (RRMM) exposed/refractory to prior alkylators: A pooled analysis of the O-12-M1 and HORIZON studies

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Background: Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate (PDC) that leverages aminopeptidases and rapidly releases alkylating agents inside tumor cells. Melflufen has a mechanism of action distinct from other alkylating agents (Slipicevic et al. AACR 2020. Abs. 1843). In the O-12-M1 (NCT01897714) and HORIZON (OP-106; NCT02963493) studies, melflufen plus dex showed meaningful efficacy and a clinically manageable safety profile in pts with RRMM (Richardson et al. Lancet Haematol. 2020;7:5; Richardson et al. J Clin Oncol. 2020;Dec 9 [Epub]). This pooled analysis examines pts from these studies exposed to prior alkylators. Methods: Both the O-12-M1 and HORIZON studies included pts with RRMM who received ≥ 2 prior lines of therapy (LoTs) and had a primary endpoint of overall response rate (ORR). Secondary endpoints included progression-free survival (PFS) and safety. Data from the 2 studies were pooled and analyzed according to previous exposure and refractoriness to alkylators before study entry. Refractoriness to prior alkylator therapy was defined as disease that failed to achieve a minimal response or progressed while on therapy, or within 60 d of last therapy. Results: Of 202 pts (HORIZON: n = 157, cutoff January 14, 2020; O-12-M1: n = 45, cutoff October 29, 2019), 178 (88%) had been exposed to alkylators in ≥ 1 prior LoT (see Table for subgroups). Pts exposed and refractory to alkylators in ≥ 2 LoTs had the highest number of pts refractory to an alkylator in the last LoT (61%), and 82% were refractory to an alkylator within 12 mo of study entry. Meaningful response rates were seen in all subgroups, except for pts who were exposed and refractory to alkylators in ≥ 2 prior LoTs (see Table). PFS trended toward being shorter with higher exposure and refractoriness to prior alkylators. Results should be interpreted with caution due to limited pt numbers. Grade 3/4 adverse events (AEs) were similar between pts exposed to prior alkylators (O-12-M1: 85%; HORIZON: 89%) and the overall population (O-12-M1: 84%; HORIZON: 89%). The most common AEs were hematologic, but were mostly reversible and clinically manageable. Nonhematologic AEs were infrequent and primarily grade 1/2. Conclusions: Melflufen in combination with dex showed meaningful efficacy and a clinically manageable safety profile in pts with RRMM exposed/refractory to prior alkylators. Clinical trial information: NCT02963493 and NCT01897714. [Table: see text]

Perceptions of prognosis in caregivers of multiple myeloma (MM) patients

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Background: Caregivers of patients with cancer play a critical role in supporting patients when making informed decisions about their medical care. Although MM patients and their caregivers face an incurable illness, data describing caregiver perceptions of the patient’s prognosis and factors associated with accurate prognostic perceptions are lacking. Methods: We conducted a cross-sectional, multisite study of caregivers of MM patients between 6/2020-1/2021. Eligible caregivers were identified by the patient as the primary caregiver and enrolled in 1 of 3 cohorts based on lines of therapy: 1) caregivers of newly diagnosed patients receiving first-line therapy; 2) 2-3 lines; 3) ≥4 lines. Caregivers completed the Perception of Treatment and Prognosis Questionnaire to assess their perceptions of the illness and prognosis. We also used the CareGiver Oncology Quality of Life (QOL) questionnaire, the Hospital Anxiety and Depression Scale, the Post-Traumatic Stress Disorder Checklist–Civilian Version, and the Brief COPE to assess caregiver QOL, psychological distress, and coping strategies. We used a multivariate logistic regression analysis to examine whether caregiver factors (i.e. demographics), line of therapy, QOL, psychological distress, or coping were associated with caregiver perceptions of the patient’s prognosis. Results: We enrolled 113 caregivers of MM patients (newly diagnosed (n=39), 2-3 lines (n=37), and ≥ 4 lines (n=37)). Overall, 89.2% (99/111) of caregivers reported that it is ‘extremely’ or ‘very’ important to know about the patient’s prognosis and the majority (58.0%, 65/112) stated that they had received adequate information regarding the patient’s prognosis. Caregivers reported that prognostic information was ‘extremely’ or ‘very’ helpful in making decisions about treatment (93.3%, 97/104), preparing for the future (88.2%, 90/102), and coping with the disease (85.6%, 89/104). Most caregivers (84.7%, 94/111) reported that the oncologist told them the patient’s cancer was incurable. In contrast, only 53.6% (59/110) of caregivers reported that they thought the patient’s cancer was incurable and 48.6% (52/107) acknowledged that the patient is terminally ill. In a multivariate analysis, we found that the use of positive reframing coping (OR=0.71, 95%CI=0.52-0.97, P=0.033) was associated with lower odds of reporting an accurate perception of prognosis. Caregiver demographics, line of therapy, QOL, and psychological distress were not associated with their perceptions of the patient’s prognosis. Conclusions: Although the majority of caregivers of MM patients report that knowing the patient’s prognosis is extremely important, a substantial minority still have significant misperceptions of the patient’s prognosis. Interventions are needed to promote effective coping and enhance caregiver perceptions of the patient’s prognosis to facilitate informed decision-making in this population.

miR-15a/16-1 deletion in activated B cells promotes plasma cell and mature B-cell neoplasms

Chromosome 13q deletion [del(13q)], harboring the miR-15a/16-1 cluster, is one of the most common genetic alterations in mature B-cell malignancies, which originate from germinal center (GC) and post-GC B cells. Moreover, miR-15a/16 expression is frequently reduced in lymphoma and multiple myeloma (MM) cells without del(13q), suggesting important tumor-suppressor activity. However, the role of miR-15a/16-1 in B-cell activation and initiation of mature B-cell neoplasms remains to be determined. We show that conditional deletion of the miR-15a/16-1 cluster in murine GC B cells induces moderate but widespread molecular and functional changes including an increased number of GC B cells, percentage of dark zone B cells, and maturation into plasma cells. With time, this leads to development of mature B-cell neoplasms resembling human extramedullary plasmacytoma (EP) as well as follicular and diffuse large B-cell lymphomas. The indolent nature and lack of bone marrow involvement of EP in our murine model resembles human primary EP rather than MM that has progressed to extramedullary disease. We corroborate human primary EP having low levels of miR-15a/16 expression, with del(13q) being the most common genetic loss. Additionally, we show that, although the mutational profile of human EP is similar to MM, there are some exceptions such as the low frequency of hyperdiploidy in EP, which could account for different disease presentation. Taken together, our studies highlight the significant role of the miR-15a/16-1 cluster in the regulation of the GC reaction and its fundamental context-dependent tumor-suppression function in plasma cell and B-cell malignancies.

Melflufen and Dexamethasone in Heavily Pretreated Relapsed and Refractory Multiple Myeloma

PURPOSE

Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that targets aminopeptidases and rapidly and selectively releases alkylating agents into tumor cells. The phase II HORIZON trial evaluated the efficacy of melflufen plus dexamethasone in relapsed and refractory multiple myeloma (RRMM), a population with an important unmet medical need.

PATIENTS AND METHODS

Patients with RRMM refractory to pomalidomide and/or an anti-CD38 monoclonal antibody received melflufen 40 mg intravenously on day 1 of each 28-day cycle plus once weekly oral dexamethasone at a dose of 40 mg (20 mg in patients older than 75 years). The primary end point was overall response rate (partial response or better) assessed by the investigator and confirmed by independent review. Secondary end points included duration of response, progression-free survival, overall survival, and safety. The primary analysis is complete with long-term follow-up ongoing.

RESULTS

Of 157 patients (median age 65 years; median five prior lines of therapy) enrolled and treated, 119 patients (76%) had triple-class-refractory disease, 55 (35%) had extramedullary disease, and 92 (59%) were refractory to previous alkylator therapy. The overall response rate was 29% in the all-treated population, with 26% in the triple-class-refractory population. In the all-treated population, median duration of response was 5.5 months, median progression-free survival was 4.2 months, and median overall survival was 11.6 months at a median follow-up of 14 months. Grade ≥ 3 treatment-emergent adverse events occurred in 96% of patients, most commonly neutropenia (79%), thrombocytopenia (76%), and anemia (43%). Pneumonia (10%) was the most common grade 3/4 nonhematologic event. Thrombocytopenia and bleeding (both grade 3/4 but fully reversible) occurred concomitantly in four patients. GI events, reported in 97 patients (62%), were predominantly grade 1/2 (93%); none were grade 4.

CONCLUSION

Melflufen plus dexamethasone showed clinically meaningful efficacy and a manageable safety profile in patients with heavily pretreated RRMM, including those with triple-class-refractory and extramedullary disease.

Immunotherapeutic and Targeted Approaches in Multiple Myeloma

The multiple myeloma (MM) therapeutic landscape has evolved significantly with the approval of numerous novel agents, including next generation proteasome inhibitors (PIs), immunomodulatory agents (IMIDs), and monoclonal antibodies (MoABs) targeting CD38 and SLAMF7. While these discoveries have led to an unprecedented improval in patient outcomes, the disease still remains incurable. Immunotherapeutic approaches have shown substantial promise in recent studies of chimeric antigen receptor T-cell (CAR T-cell) therapy, bispecific antibodies, and antibody drug conjugates targeting B-cell maturation antigen (BCMA). This review will highlight these novel and targeted therapies in MM, with particular focus on PIs, IMIDs, MoAb and BCMA-directed immunotherapy.

A phase II, single-arm study of denosumab in multiple myeloma patients with renal insufficiency

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Background: Bone destruction is a devastating consequence of multiple myeloma (MM). An unmet medical need exists for the management of skeletal complications in MM patients with renal insufficiency. Despite the effectiveness of intravenous bisphosphonates, their use is limited in situations where renal dysfunction is present. Denosumab is a fully human monoclonal IgG2 antibody to RANKL that has been shown to be non-inferior to zoledronic acid for SRE rates in MM (Raje, et al. Lancet Oncol). More importantly, it does not have the same renal toxicity as the bisphosphonates. We hypothesize that denosumab can be safely and effectively administered in MM patients with renal insufficiency to improve bone health. This may fill a gap in clinical care for bone-directed therapy in this patient population. Methods: This multi-center study will include forty adult patients with newly diagnosed or relapsed MM with a creatinine clearance of less than 30 mL/min (NCT02833610). All patients will receive a subcutaneous injection of denosumab 120 mg Q4W for a total of 12 cycles. In addition, it is required that all subjects receive daily vitamin D and calcium supplementation at standard doses (at least 2000 mg calcium citrate and1000 IU of vitamin D), unless documented hypercalcemia develops on study. The primary objective is to assess the effect of denosumab 120 mg Q4W on serum c-terminal telopeptide (sCTX). Secondary objectives include evaluation of safety and tolerability of denosumab in patients with renal insufficiency, incidence of hypocalcemia, effect on bone mineral density, effect on urinary n-terminal telopeptide, and proportion of patients who have a documented skeletal-related event. Results: At the time of this analysis, a total of 20 out of a planned 40 patients have been enrolled, including 9 women, 11 men. Of those treated, 8 patients have completed the planned 12 cycles of therapy. Hypocalcemia was observed in 7 (35%) patients. Four patients (20%) experienced grade 3 hypocalcemia, 3 (15%) grade 2 or less. Two patients developed osteonecrosis of the jaw, one (5%) grade 1 and one (5%) grade 4 event. Data for the analysis of the primary endpoint of sCTX levels will be presented. Conclusions: Investigation of denosumab in MM patients with renal insufficiency defined as a creatinine clearance less than 30 mL/min is ongoing. Early data support that denosumab can be safely administered in this population. However, incidence of hypocalcemia despite aggressive prophylactic calcium dosing underscores the importance of the trial to inform safe practice in this more fragile population. Clinical trial information: NCT02833610 .

FOLFOX and nab-paclitaxel (nab-P) for advanced pancreatic cancer: A phase I study

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Background: FOLFIRINOX improves survival in advanced pancreatic cancer, however the contribution of irinotecan is uncertain. The addition of irinotecan to gemcitabine was not superior to gemcitabine alone in pancreatic cancer, however nab-P demonstrates a survival benefit. This phase I study was designed to evaluate the maximum tolerated dose (MTD) of the addition of nab-P to fluorouracil, leucovorin, oxaliplatin (FOLFOX-A). Methods: Patients with metastatic or locally advanced pancreatic adenocarcinoma without prior treatment received oxaliplatin, 85 mg/m2, leucovorin 400 mg/m2 and 5-FU 2400 mg/m2 with 3 dose levels of nab-P (125, 150 and 175 mg/m2) every 2 weeks. Pegfilgrastim was required during the first 2 cycles. Dose limiting toxicities (DLTs) were defined in the first 2 cycles of treatment. Results: Fifteen patients were entered: Dose level 1 (n=6), dose level 2 (N=6), dose level 3 (N=3). The median age was 64 (35-81). Ten patients had metastatic and 5 had locally advanced disease. DLTs of nausea and fatigue occurred in 2 of 3 patients at dose level 3. Two patients developed grade 3 neuropathy after >= 10 cycles of treatment. One patient had grade 3/4 neutropenia. Eight of fifteen patients (53%) had a partial response. Conclusions: The MTD of nab-P is 150mg/m2 every 2 weeks with FOLFOX. Cumulative peripheral neuropathy, similar to other FOLFOX regimens, is the most significant toxicity generally occurring after >= 10 cycles of treatment. FOLFOX-A has substantial activity and may represent a promising regimen in pancreatic cancer. Patients are currently being accrued to an expansion phase utilizing dose level 2. Supported by the Davis and Browning families and LIFEcycle. Clinical trial information: NCT01744353.

Prevalence of venous thromboembolism in patients with secondary polycythemia

To investigate an association between secondary polycythemia and venous thromboembolism (VTE) risk, we performed a case-control study to compare the prevalence of VTE in participants with secondary polycythemia due to chronic obstructive pulmonary disease (COPD; N = 86) to that in age- and sex-matched controls with COPD without secondary polycythemia (N = 86). Although there was a significant difference in mean hematocrit between cases and controls (53.5% vs 43.6%, respectively; P < .005), we identified no difference in the number of total or idiopathic VTE events in the 2 groups. Patients with VTE, however, had a significantly higher body mass index than patients without VTE. Our findings suggest that secondary polycythemia alone may not be a significant risk factor for VTE but that VTE risk in this population may be related to known risk factors such as obesity. The role of phlebotomy for VTE risk reduction secondary polycythemia is therefore questionable.

Although substantial (qol) quality of life problems may occur due to acute and delayed complications of therapy for advanced head & neck squamous cancer, overall long term qol is good/acceptable

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Background: Patients with locally advanced head and neck squamous cell cancer (HNSCCA) have traditionally been treated with aggressive regimens of concurrent chemo-radiation, or more recently, induction chemotherapy followed by concurrent chemo-radiation, to achieve high rates of tumor control at our institution. Objectives: We initiated a QOL study in patients who were free of tumor and available for long term follow up with a focus on acute & delayed complications and long term QOL observation. Methods: The study included 75 patients with stage III-IV HNSCCA treated with either concurrent chemo-radiation or induction chemotherapy followed by concurrent chemo-radiation at our institution. All patients had completed therapy and were considered free of disease at the time of survey. We were unable to complete the survey in 43 pts largely due to patient access problems or unavailability at time of survey. In the remaining 32 patients, the University of Washington QOL survey could be completed over the telephone. Two pts were excluded due to recent demonstration of recurrence. Additional information regarding acute toxicity during treatment was also recorded. Results: There were 11 women and 19 men with a median duration of follow up of 36 months (range 3–120 months) after completion of treatment. Early complications were associated with gastrostomy tube placement (5 leaks & 6 infections,12/31 patients, 38.7%) and portacath placements (2 deep vein thrombosis requiring port removal and anticoagulation, 6.45%). No patients in this group were still dependent on their gastrostomy tube for nutrition at the time of follow up. Of note, 9% of patients were still smoking and drinking on a regular basis. The composite scores for 9 QOL domains ranged from 370–875, with a median score of 615/900. Major problem issues regarding QOL were associated saliva 11/31 (35.5%), swallowing 10/31 (32.2%), followed by mood 6/31 (19.3%), pain 5/31 (16.12%), chewing 4/31 (12.9%), local pain 5/31 (16.12%) and shoulder problems 5/31 (16.12%). Conclusion: Initial QOL problems in advanced HNSCCA appear related to surgical/chemo therapy related problems, whereas late QOL issues appear primarily related to radiation. Most patients however had a good or acceptable quality of life after treatment for advanced HNSCCA.

No significant financial relationships to disclose.