Faculty Bibliography

INTRODUCTION:The objective was to assess the benefit of pomalidomide-based combination regimens in patients with relapsed/refractory multiple myeloma (RRMM) previously treated with lenalidomide. A pooled estimate was obtained for efficacy outcomes including overall response rate (ORR), complete response (CR) rate, and progression-free survival (PFS) based on multiple trials conducted in this patient population. PATIENTS AND METHODS:A literature search was conducted on March 22, 2022 for relevant trials published between January 1, 2016 and the search date. The search identified 12 eligible trials with publications dated between 2016 and 2021. The meta-analyses were conducted among the intention-to-treat (ITT) population (patients treated in all lines of therapy) and 2 subpopulations: 2L (only patients treated in the second line [2L]) and ≥2L (patients treated in the 2L and beyond). RESULTS:From the meta-analyses, ORR was 69.9% for ITT, 74.4% for ≥2L, and 87.2% for 2L. CR rate was 12.1% for ITT, 17.6% for ≥2L, and 29.7% for 2L. One-year PFS rates were 55.1% for ITT, 59.1% for ≥2L, and 74.0% for 2L. Two-year PFS rates were 29.3% for ITT, 36.0% for ≥2L, and 41.9% for 2L. CONCLUSION:Pomalidomide-based combination regimens were effective in patients with RRMM previously treated with lenalidomide and tended to be associated with better outcomes when used earlier in the treatment pathway. A drug class switch may not always be necessary when making treatment decisions for patients with RRMM for whom the benefits of lenalidomide have been exhausted, although this must be supported by comparative studies.

PURPOSE/OBJECTIVE:Chromosome 1 (chr1) copy number abnormalities (CNAs) and structural variants (SV) are frequent in newly diagnosed multiple myeloma (NDMM) and associate with a heterogeneous impact on outcome the drivers of which are largely unknown. EXPERIMENTAL DESIGN/METHODS:A multiomic approach comprising CRISPR, gene mapping of CNA and SV, methylation, expression, and mutational analysis was used to document the extent of chr1 molecular variants and their impact on pathway utilisation. RESULTS:We identified two distinct groups of gain(1q): focal gains associated with limited gene expression changes and a neutral prognosis, and whole-arm gains, which associate with substantial gene expression changes, complex genetics and an adverse prognosis. CRISPR identified a number of dependencies on chr1 but only limited variants associated with acquired CNAs. We identified seven regions of deletion, nine of gain, three of chromothripsis (CT) and two of templated-insertion (TI), which contain a number of potential drivers. An additional mechanism involving hypomethylation of genes at 1q may contribute to the aberrant gene expression of a number of genes. Expression changes associated with whole-arm gains were substantial and gene set enrichment analysis identified metabolic processes, apoptotic resistance, signaling via the MAPK pathway, and upregulation of transcription factors as being key drivers of the adverse prognosis associated with these variants. CONCLUSIONS:Multiple layers of genetic complexity impact the phenotype associated with CNAs on chr1 to generate its associated clinical phenotype. Whole-arm gains of 1q are the critically important prognostic group that deregulate multiple pathways, which may offer therapeutic vulnerabilities.

In most patients with myeloma, the tumour cell produces a unique monoclonal immunoglobulin (Mig), which serves as a quantitative surrogate biomarker for tumour burden. Patients with non-secretory myeloma (NSM) represent 1%-3% of patients and do not produce a Mig suitable for standard monitoring. Therefore, clinicians rely on bone marrow biopsies and CT-PET/ WB MRI scans, which are challenging for patients/clinicians, especially when required regularly for monitoring. Consequently, there is an unmet need for a blood-based biomarker in this patient group to determine remission induction and disease relapse. We have developed a new method to detect monoclonal light chains in this series of patients with NSM, (negative on immunofixation and no measurable disease marker (sFLC <100 mg/L)). Isoelectric focusing (IEF) is well-established for detecting IgG oligoclonal banding in cerebrospinal fluid to diagnose multiple sclerosis. Using IEF, any monoclonal immunoglobulin displays a highly reproducible unique spectrotype of bands. We have developed serum IEF to identify monoclonal sFLCs using highly specific and sensitive monoclonal antibodies. Study patients were identified from the MRC Myeloma IX, CRUK Myeloma XI or NIHR TEAMM trials. Overall, serum IEF detected monoclonal FLC in 28/32 patients (88%): 14 patients with kappa FLC and 10 lambda FLC. One patient had both kappa and lambda FLC bands detected, likely reflecting bi-clonality with both active myeloma clone and secondary MGUS clone picked up by the sensitive IEF assay. Follow-up samples were available in 27/32 patients. Serum IEF identified response to therapy (disappearance of band) and relapse (reappearance of band). The method also allows serial sample dilution to determine percentage reduction in monoclonal protein and provide semi-quantitative results in response to therapy. The IEF method identified monoclonal FLC in 86% of NSM patients studied, indicating that most are low-level secretors rather than true non-producers. Although their Mig cannot be monitored using standard techniques, our highly sensitive IEF assay allows NSM patients to be diagnosed and monitored using blood samples. This approach could reduce reliance on bone marrow biopsy and imaging in this patient cohort. Mass spectrometry (MS) is emerging as another exciting blood-based option for Mig detection. However, the limit of detection for MS is <10 mg/L compared to IEF sensitivity <1 mg/L. Further, the IEF assay utilises a low-cost electrophoresis platform available in many laboratories that conduct myeloma testing, enabling easier integration into clinical practice. Future clinical studies are required to validate IEF and should include comparison to other technologies, including MS

Prediction of individual patient benefit from lenalidomide (Len) maintenance post autologous transplant (ASCT) remains challenging. We investigated here extended molecular profiling for outcome prediction in NCRI Myeloma XI (MyXI) trial patients. MyXI patients randomized to Len maintenance or observation post-ASCT were genetically profiled for t(4;14), t(14;16), t(14;20), del(1p), gain(1q) and del(17p) and co-occurrence of risk markers computed. PFS, PFS2 and OS were calculated from maintenance randomization, and groups compared using Cox proportional hazards regression. 556 MyXI patients, 17% with double hit MM (≥2 risk markers), 32% with single hit (1 risk marker) and 51% without risk marker, were analyzed. Single hit MM derived the highest PFS benefit from Len maintenance, specifically isolated del(1p), del(17p) and t(4;14), with approximately 40-fold (HR 0.02; 95% CI: 0.002-0.24; P=0.0012), 10-fold (HR 0.1; 95% CI: 0.02-0.58; P=0.0095) and 7-fold (HR 0.14; 95% CI: 0.04-0.45; P=0.0009) reduced risk of progression or death (PFS) compared to observation, respectively. This benefit translated into improved PFS2 HR 0.27 (95% CI: 0.13-0.54; P=0.0002) and OS HR 0.41 (95% CI: 0.18-0.93; P=0.03) for this group of patients over observation; median PFS was 10.9 vs. 57.3 months for observation vs. Len maintenance. Patients with isolated gain(1q) derived no benefit, and double hit MM limited benefit, regardless or risk lesions involved, from Len maintenance. Extended genetic profiling identifies patients deriving exceptional benefit from Len maintenance and should be considered for newly diagnosed patients to support management discussions along their treatment pathway.

BACKGROUND:Infections are a common reason for hospitalization and death in multiple myeloma (MM). Although pneumococcal vaccination (PV) and influenza vaccination (FV) are recommended for MM patients, data on vaccination status and outcomes are limited in MM. MATERIALS AND METHODS/METHODS:We utilized data from the global, prospective, observational INSIGHT MM study to analyze FV and PV rates and associated outcomes of patients with MM enrolled 2016-2019. RESULTS:Of the 4307 patients enrolled, 2543 and 2500 had study-entry data on FV and PV status. Overall vaccination rates were low (FV 39.6%, PV 30.2%) and varied by region. On separate multivariable analyses of overall survival (OS) by Cox model, FV in the prior 2 years and PV in the prior 5 years impacted OS (vs. no vaccination; FV: HR, 0.73; 95% CI, 0.60-0.90; P = .003; PV: HR, 0.51; 95% CI, 0.42-0.63; P < .0001) when adjusted for age, region, performance status, disease stage, cytogenetics at diagnosis, MM symptoms, disease status, time since diagnosis, and prior transplant. Proportions of deaths due to infections were lower among vaccinated versus non-vaccinated patients (FV: 9.8% vs. 15.3%, P = .142; PV: 9.9% vs. 18.0%, P = .032). Patients with FV had generally lower health resource utilization (HRU) versus patients without FV; patients with PV had higher or similar HRU versus patients without PV. CONCLUSION/CONCLUSIONS:Vaccination is important in MM and should be encouraged. Vaccination status should be recorded in prospective clinical trials as it may affect survival. This trial was registered at www. CLINICALTRIALS/RESULTS:gov as #NCT02761187.

Lenalidomide is an effective maintenance agent for patients with myeloma, prolonging first remission and, in transplant eligible patients, improving overall survival (OS) compared to observation. The 'Myeloma XI' trial, for newly diagnosed patients, aimed to evaluate whether the addition of the histone deacetylase inhibitor vorinostat to the lenalidomide maintenance backbone could improve outcomes further. Patients included in this analysis were randomised to maintenance therapy with lenalidomide alone (10 mg/day on days 1-21 of each 28-day cycle), or in combination with vorinostat (300 mg/day on day 1-7 and 15-21 of each 28-day cycle) with treatment continuing until unacceptable toxicity or progressive disease. There was no significant difference in median progression-free survival between those receiving lenalidomide-vorinostat or lenalidomide alone, 34 and 40 months respectively (hazard ratio [HR] 1.18, 95% confidence interval [CI] 0.96-1.44, p = 0.109). There was also no significant difference in median OS, not estimable and 75 months respectively (HR 0.99, 95% CI 0.76-1.29, p = 0.929). Subgroup analysis demonstrated no statistically significant heterogeneity in outcomes. Combination lenalidomide-vorinostat appeared to be poorly tolerated with more dose modifications, fewer cycles of maintenance therapy delivered and higher rates of discontinuation due to toxicity than lenalidomide alone. The trial did not meet its primary end-point, there was no benefit from the addition of vorinostat to lenalidomide maintenance.

PURPOSE/OBJECTIVE:Molibresib is a selective, small molecule inhibitor of the BET protein family. This was an open-label, two-part, Phase I/II study investigating molibresib monotherapy for the treatment of hematological malignancies (NCT01943851). EXPERIMENTAL DESIGN/METHODS:Part 1 (dose escalation) determined the recommended Phase 2 dose (RP2D) of molibresib in patients with acute myeloid leukemia (AML), non-Hodgkin's lymphoma (NHL), or multiple myeloma. Part 2 (dose expansion) investigated the safety and efficacy of molibresib at the RP2D in patients with relapsed/refractory myelodysplastic syndrome (MDS; as well as AML evolved from antecedent MDS) or cutaneous T cell lymphoma (CTCL). The primary endpoint in Part 1 was safety and the primary endpoint in Part 2 was objective response rate (ORR). RESULTS:There were 111 patients enrolled (87 in Part 1, 24 in Part 2). Molibresib RP2Ds of 75 mg QD (for MDS) and 60 mg QD (for CTCL) were selected. Most common Grade 3+ AEs included thrombocytopenia (37%), anemia (15%) and febrile neutropenia (15%). Six patients achieved complete responses (three in Part 1 [two AML, one NHL], three in Part 2 [MDS]), and seven patients achieved partial responses (six in Part 1 [four AML, two NHL], one in Part 2 [MDS]). The ORRs for Part 1, Part 2, and the total study population were 10% (95% CI: 4.8-18.7), 25% (95% CI: 7.3-52.4), and 13% (95% CI: 6.9-20.6), respectively. CONCLUSIONS:While anti-tumor activity was observed with molibresib, use was limited by gastrointestinal and thrombocytopenia toxicities. Investigations of molibresib as part of combination regimens may be warranted.

Aminopeptidases, which catalyze the cleavage of amino acids from the amino terminus of proteins, are widely distributed in the natural world and play a crucial role in cellular processes and functions, including metabolism, signaling, angiogenesis, and immunology. They are also involved in the homeostasis of amino acids and proteins that are required for cellular proliferation. Tumor cells are highly dependent on the exogenous supply of amino acids for their survival, and overexpression of aminopeptidase facilitates rapid tumor cell proliferation. In addition, clinical studies have demonstrated that patients with cancers with high aminopeptidase expression often have poorer outcomes. Emerging evidence supports the rationale of inhibiting aminopeptidase activity as a targeted approach for novel treatment options, as limiting the availability of amino acids can be selectively lethal to tumor cells. While there are agents that directly target aminopeptidases that demonstrate potential as cancer therapies, such as bestatin and tosedostat, more selective and more targeted therapeutic approaches are needed. This article specifically looks at the biological role of aminopeptidases in both normal and cancer processes, and their potential as a biological target for future therapeutic strategies. When examining previous publications, most do not cover aminopeptidases and their role in cancer processes. Aminopeptidases play a vital role in cell processes and functions; however, their overexpression may lead to a rapid proliferation of tumor cells. Emerging evidence supports the rationale of leveraging aminopeptidase activity as a targeted approach for new oncological treatments. This article specifically looks at the biological role of aminopeptidases in both normal and cancer processes, and their potential as a biological target for future therapeutic strategies.