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

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

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

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

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

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

A phase-1 trial of linsitinib (OSI-906) in combination with bortezomib and dexamethasone for the treatment of relapsed/refractory multiple myeloma.

We report results of a phase-1 study evaluating the safety and anti-cancer activity of the small molecule insulin-like growth factor-1 receptor (IGF-1R) inhibitor, linsitinib combined with bortezomib, and dexamethasone in relapsed/refractory multiple myeloma. Nineteen patients were enrolled across four dose-escalation cohorts (75-150 mg bid). The maximum tolerated dose of linsitinib was 125 mg. The most frequent Grade 3/4 AEs occurring in ≥10% of patients were thrombocytopenia (53%), bone pain (26%), neutropenia (21%), diarrhea (14%), anemia (14%), rash (10%), and lung infection (10%). Study discontinuation due to treatment-related AEs was low (16%). Across all cohorts the ORR was 61% (95% CI: 28.9-75.6%). Three partial response or greater and one stable disease were observed in proteasome inhibitor (PI) refractory patients (n = 5). Median PFS was 7.1 months (95% CI: 3.6-NA). Linsitinib plus bortezomib and dexamethasone demonstrate a manageable safety profile while the clinical benefit particularly in PI refractory patients warrants further exploration.

An open-label, pharmacokinetic study of lenalidomide and dexamethasone therapy in previously untreated multiple myeloma (MM) patients with various degrees of renal impairment - validation of official dosing guidelines.

Lenalidomide is a backbone agent in the treatment of multiple myeloma, but dose adjustment is required for those with renal impairment (RI). We evaluated the pharmacokinetics (PK) and safety of lenalidomide and dexamethasone as frontline pre-transplant induction, with doses adjusted at start of each cycle based on creatinine clearance, as per the official dosing guidelines. After 4 cycles, PK studies showed that patients with moderate RI (30 ≤ CrCl < 60 mL/min) receiving 10 mg dosing may be under-dosed and those with severe RI (CrCl <30ml/min) appeared appropriately dosed initially, but sustained significant decreases in maximum serum concentration (Cmax) after repeated dosing, due to rapid clinical improvement and enhanced drug clearance. PK drug monitoring during cycle 1 may facilitate appropriate and timely dose adjustments. Adverse events rates did not vary based on severity of RI. No patient discontinued lenalidomide for toxicity. This supports the feasibility and safety of frontline lenalidomide in transplant-eligible patients with RI.

A phase 2 study of lenalidomide and dexamethasone in previously untreated patients with chronic lymphocytic leukemia (CLL).

Lenalidomide has anti-tumor activity in CLL but can be complicated by tumor lysis syndrome (TLS) and tumor flare (TF). In our previous study using low-dose lenalidomide in treatment-naive CLL, TLS was averted but TF remained frequent and complete responses (CR) were rare, despite treatment to progression. The addition of dexamethasone may mitigate TF and enable lenalidomide dose escalation, achieving durable response without long-term use. In this phase 2 trial, 31 treatment-naive CLL patients received lenalidomide (target 25mg daily) plus dexamethasone for a finite 18 cycles. No patients developed TLS and TF was infrequent. Overall responses were 74.2% (CR 9.7%) and median progression-free survival 27 months. Cereblon-binding proteins IKZF1 and IKZF3 were largely downregulated, with associated increased IRF4 levels. We therefore report that lenalidomide plus dexamethasone can achieve durable responses in a subset of patients without continuing therapy until progression. Upregulation of IRF4 may contribute to anti-CLL activity of immunomodulatory agents. This trial was registered at www.clinicaltrials.gov as NCT01133743.

A phase 2 study of ofatumumab (Arzerra®) in combination with a pan-AKT inhibitor (afuresertib) in previously treated patients with chronic lymphocytic leukemia (CLL).

AKT plays a centralized role in tumor proliferation and survival and is aberrantly activated in chronic lymphocytic leukemia (CLL). In this phase 2 trial, 30 relapsed/refractory CLL patients were treated with combination afuresertib, a novel oral AKT inhibitor, and ofatumumab for 6 months, followed by afuresertib maintenance for 12 months. We aimed to achieve deeper and more durable responses, without requiring long-term continuous treatment. Treatment was generally well tolerated but respiratory infections were common, with 18% severe requiring hospitalization. Hematologic toxicities were manageable (grade 3-4 neutropenia 39%). At a median follow-up of 13.4 months, overall responses were 50% (complete responses 3.6%). Median progression-free survival was 8.5 months and overall survival 34.8 months. Combination therapy with ofatumumab and afuresertib is active and well tolerated, but does not appear to lead to durable responses and may not provide additional benefit over single-agent ofatumumab in relapsed/refractory CLL. Novel agent combinations are currently undergoing intense investigation.

Single-agent lenalidomide in the treatment of previously untreated chronic lymphocytic leukemia.

PURPOSE: Lenalidomide is an oral immunomodulatory drug with multiple effects on the immune system and tumor cell microenvironment leading to inhibition of malignant cell growth. Based on encouraging reports of lenalidomide in relapsed and refractory chronic lymphocytic leukemia (CLL), we investigated the first-line use of single-agent lenalidomide in CLL. PATIENTS AND METHODS: Using a starting dose of lenalidomide 10 mg/d for 21 days of a 28-day cycle and weekly 5-mg dose escalations to a target of 25 mg, we encountered severe toxicities (tumor lysis, fatal sepsis) in the first two patients enrolled. The study was halted and the protocol amended to a more conservative regimen: starting dose of lenalidomide 2.5 mg with monthly escalations to a target dose of 10 mg, and extended tumor lysis prophylaxis and monitoring. Gene expression profiles from patient samples before and after 7 days of lenalidomide were performed. RESULTS: Twenty-five patients were enrolled on the amended protocol. No further tumor lysis events were reported. Tumor flare was common (88%) but mild. Grade 3 to 4 neutropenia occurred in 72% of patients, with only five episodes of febrile neutropenia. The overall response rate was 56% (no complete responses). Although rapid peripheral lymphocyte reductions were observed, rebound lymphocytoses during the week off-therapy were common. Lenalidomide-induced molecular changes enriched for cytoskeletal and immune-related genes were identified. CONCLUSION: Lenalidomide is clinically active as first-line CLL therapy and is well-tolerated if a conservative approach with slow dose escalation is used. A lenalidomide-induced molecular signature provides insights into its immunomodulatory mechanisms of action in CLL.