Clinical Benefit of Long-Term Disease Control with Pomalidomide and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients

Lenalidomide plus Dexamethasone Combination as First-Line Oral Therapy of Multiple Myeloma Patients: A Unicentric Real-Life Study

Based on the results obtained in clinical trials, the use of the combination of lenalidomide and dexamethasone (Len/Dex) has become a potential therapeutic choice for newly diagnosed multiple myeloma (NDMM) ineligible for autologous stem cell transplantation. This study evaluated 89 frail NDMM patients treated with first-line oral association. At the last follow-up, 34 out of 89 patients (38.2%) were alive, and 22 were still in treatment with Len/Dex. Among 73 evaluable patients who received at least two cycles, the overall response rate was 71% (N = 52). The disease control rate, defined as any level of clinical response to therapy, occurred in 71 patients (97%). We reported one or more adverse events of grade 3 or 4 (G3/4) in 65.2% (N = 58) of patients, with a prevalence of hematological toxicity (24 patients), leading to an overall discontinuation of treatment in two cases. In univariate analysis, high ISS, high serum β2-microglobulin, and creatinine clearance <30 mL/min negatively impact OS, while the depth of response positively impacts OS. Moreover, G3-4 anemia, ISS, frailty score, and ECOG negatively impacts PFS. In conclusion, elderly and more frail patients benefit from the Len/Dex combination also in the era of monoclonal antibodies, ensuring an increased PFS and OS in patients where the therapeutic choice is often limited and usually not very effective.

Efficacy and safety of daratumumab combined with all-trans retinoic acid in relapsed/refractory multiple myeloma

The efficacy of daratumumab depends partially on CD38 expression on multiple myeloma (MM) cells. We have previously shown that all-trans retinoic acid (ATRA) upregulates CD38 expression and reverts daratumumab-resistance ex vivo. We therefore evaluated the optimal dose, efficacy, and safety of daratumumab combined with ATRA in patients with daratumumab-refractory MM in a phase 1/2 study (NCT02751255). In part A of the study, 63 patients were treated with daratumumab monotherapy. Fifty patients with daratumumab-refractory MM were subsequently enrolled in part B and treated with daratumumab (reintensified schedule) combined with ATRA until disease progression. The recommended phase 2 dose of ATRA in combination with daratumumab was defined as 45 mg/m2. At this dose, the overall response rate (ORR) was 5%, indicating that the primary endpoint (ORR ≥15%) was not met. However, most patients (66%) achieved at least stable disease. After a median follow-up of 43 months, the median progression-free survival (PFS) for all patients was 2.8 months. Patients who previously achieved at least a partial response or minimal response/stable disease with prior daratumumab monotherapy had a significantly longer PFS compared with patients who immediately progressed during daratumumab as single agent (median PFS 3.4 and 2.8 vs 1.3 months). The median overall survival was 19.1 months. The addition of ATRA did not increase the incidence of adverse events. Flow cytometric analysis revealed that ATRA temporarily increased CD38 expression on immune cell subsets. In conclusion, the addition of ATRA and reintensification of daratumumab had limited activity in patients with daratumumab-refractory MM, which may be explained by the transient upregulation of CD38 expression. This trial was registered at www.clinicaltrials.gov as #NCT02751255.

Pomalidomide plus dexamethasone for patients with relapsed or refractory multiple myeloma: Final results of the non-interventional study POSEIDON and comparison with the pivotal phase 3 clinical trials

Background

Prognosis of patients with multiple myeloma (MM) who have relapsed on or become refractory to immunomodulators and bortezomib is poor, and treatment options are limited. While pomalidomide plus low‐dose dexamethasone (POM/DEX) has demonstrated efficacy in clinical trials, real‐world evidence is scarce.

Patients and Methods

POSEIDON was a prospective non‐interventional study designed to evaluate effectiveness, safety and quality of life (QoL) of POM/DEX in patients with relapsed or refractory MM (R/RMM) pretreated with at least two prior therapy lines including both lenalidomide and bortezomib in real world in Germany. Patients received POM/DEX according to physicians’ choice. Data were analyzed descriptively.

Results

Between 2014 and 2017, 151 patients were enrolled, 144 patients with a median of three prior therapy lines qualified for effectiveness analysis. Median age was 73.2 years. Median progression‐free and overall survival were 6.3 months [95% confidence interval (CI) 5.2, 8.6] and 12.9 months [95% CI 10.6, 15.1]. Most frequent grade 3/4 adverse events were leukopenia (8.2%), pneumonia (7.5%) and anemia (5.5%). QoL was maintained after start of POM/DEX.

Conclusion

The results of POSEIDON support the effectiveness and safety of POM/DEX in R/RMM patients pretreated with lenalidomide and bortezomib and highlight the clinical value of the POM/DEX regimen in the real‐world setting.

Registered at clinicaltrials.gov (NCT02075996).

Lenalidomide and Pomalidomide Improve Function and Induce FcγRI/CD64 in Multiple Myeloma Neutrophils

Background Myeloid dysfunction is an emerging hallmark of microenvironment changes occurring in multiple myeloma (MM). Our previous work showed that FcγRI/CD64 overexpression in neutrophils of newly diagnosed MM patients is associated to inferior outcomes, reduced oxidative bursts and phagocytosis, with an increased risk of bacterial infections. Pomalidomide is a novel immune-modulatory drug approved for relapsed/refractory patients (RRMM), with drug-related neutropenia as major limitation to treatment. Patients and methods Herein, we describe a prospective analysis of 51 consecutive RRMM patients treated with pomalidomide and dexamethasone (PomDex) from March 2015 through December 2016, associated with secondary prophylaxis with filgrastim (G-CSF) in case of neutrophil count <1500 cells/μL. Neutrophil function was investigated by flow cytometry, including the phagocytosis, oxidative bursts, and median fluorescence intensity of FcγRI-CD64. Controls included a group of newly diagnosed symptomatic MM (NDMM), asymptomatic (smoldering myeloma, MGUS) and healthy subjects referred to our Center in the same time-frame. Results Compared to controls, RRMM neutrophils had higher expression of FcγRI/CD64 and lower phagocytic activity and oxidative bursts. We maintained median leukocyte counts higher than 3.5 × 10⁹/L for 6 cycles, and median neutrophil counts higher than 1.5 × 10⁹/L, with only 6 (11%) patients developing grade 3-4 infections, without pomalidomide dose reduction. After 4 cycles of PomDex, FcγRI/CD64 was further increased in neutrophils, and phagocytic activity and oxidative bursts recovered independently from filgrastim exposure and the quality of hematological responses. Similarly, in NDMM patients, lenalidomide but not bortezomib upregulated FcγRI/CD64 expression, improving phagocytic activity and oxidative bursta as tested in vitro. Conclusions Our combined biological and clinical data provide new information on the ability of pomalidomide and lenalidomide to modulate the functional activity of neutrophils, despite their chronic activation due to FcγRI/CD64 overexpression.

Daratumumab as Single Agent in Relapsed/Refractory Myeloma Patients: A Retrospective Real-Life Survey

Background

The anti-CD38 monoclonal antibody daratumumab is approved as a single agent for the treatment of patients with relapsed/refractory multiple myeloma (RRMM) who received at least three prior lines of therapy, including proteasome inhibitor and immunomodulatory agent. A retrospective multicentric study was designed to evaluate feasibility, tolerability, and efficacy of daratumumab in monotherapy in RRMM.

Methods

This study included 44 consecutive RRMM patients that underwent daratumumab monotherapy after a median number of four prior therapies (range 2–9). Patients were treated in seven Sicilian centers, as part of Sicilian Myeloma Network and three Calabrian centers outside of controlled clinical trials from August 2016 through July 2020.

Results

The regimen was well tolerated with few grade 3–4 haematological and rare non-haematological adverse events, such as pneumonia. Definitive discontinuation was due to disease progression in 25 (57%) patients. Since three patients did not complete at least one full cycle, a total of 41 patients was evaluated for response. Overall response rate was 37%, and the disease control rate (stable disease or better) was high (73%). The best achieved responses within 6 months were very good partial remission or better (27%), partial remission (10%), minimal response (14%) and stable disease (22%). After a median follow up of 7.8 months, median progression free survival (PFS) was 7.2 months and overall survival (OS) 7.8 months. Univariate analysis showed that patients with PR or better after 6 months of therapy had longer median PFS and OS (respectively 29.5 vs 3.6 months, p=0.0001 and 30.6 vs 3.9 months p=0.0001), confirmed by multivariate analysis. Furthermore, standard cytogenetic risk and biochemical relapse type had prolonged median PFS, but not OS (respectively unreached vs 2.6, p=0.03 and 23.9 vs 6.2, p=0.05) in both univariate and multivariate analysis. Additionally, univariate analysis showed that patients treated with carfilzomib-lenalidomide-dexamethasone prior to daratumumab had significantly shorter PFS compared to pomalidomide-dexamethasone (3.4 months vs 9.3 months, p=0.03), that multivariate analysis failed to confirm.

Conclusions

Our findings indicate that daratumumab as single agent is safe and well-tolerated regimen in real-life, associated to prolonged PFS and OS in responding patients. No new safety signals were identified.

Prevention of venous thromboembolic events occurring in myeloma patients treated with second-generation novel agents

Thrombosis and neoplasms are strictly linked, and the diagnosis of a malignancy is a relevant risk factor for venous thromboembolism (VTE). In particular, between gammopathies, the VTE risk is known to be increased in both monoclonal gammopathy of uncertain significance and in multiple myeloma, with a 3- and 9-fold increase respectively, when compared to the general population. The risk appears to be further increased in patients treated with immunomodulating drugs, such as thalidomide, especially when in combination with dexamethasone or conventional cytotoxic chemotherapies, and lenalidomide. In 2008 the International Myeloma Working Group put out thrombosis prophylaxis recommendations for myeloma patients treated with IMiDs. Current recommendations for thromboprophylaxis suggest the use of low-dose acetylsalicylic acid in patients with low risk for thrombosis and therapeutic dose anticoagulation with LMWH or warfarin for high-risk patients. However, these recommendations have been frequently not followed in the clinical practice, due to various reasons that involve the patients' will, the level of evidence of the recommendations and some selection biases in the studies that were taken as basis for writing down the indications. The new direct oral anticoagulants have been preliminarily evaluated for the prophylaxis of thrombotic events in IMiDs-treated myelomas, being promising, even if more expensive. Currently, the most reliable tool for a correct thrombotic risk stratification appears to be the complete clinical and anamnestic evaluation of the myeloma patients added to a strong physician awareness of the evidences that the literature contains until now.

A Real-Life Survey of Venous Thromboembolic Events Occurring in Myeloma Patients Treated in Third Line with Second-Generation Novel Agents

Compared to the general population, patients with multiple myeloma (MM) have a nine-fold increased risk of developing venous thromboembolism (VTE). Little is known about VTE prophylaxis in relapsed/refractory (RR) MM patients treated with next generation anti-myeloma drugs, such as pomalidomide (Poma) and carfilzomib (K), and monoclonal antibodies daratumumab (Dara) and elotuzumab (Elo), alone or in combination with dexamethasone at high- (D, 40 mg/week) or low-dose (d, 20 mg/week). Here, we describe the incidence of VTE in a retrospective cohort of 112 consecutive relapsed and refractory myeloma (RRMM) patients who received a third line of treatment from April 2013 to February 2020. Anti-MM regimens included combinations of pomalidomide and dexamethasone (PomaD, N = 61), carfilzomib, lenalidomide and dexamethasone (KRd, N = 31), and elotuzumab, lenalidomide and dexamethasone (EloRd, N = 10), while the remaining 10 patients received daratumumab as a single agent. According to National Comprehnsive Cancer Network (NCCN), International Myeloma Working Group (IMWG) and 2015 European Myeloma Network (EMN) guidelines, 42 patients (38%) were classified as high-risk patients. According to the IMPEDE VTE score, 32 patients (28%) were classified as low-risk, with a score ≤ 3 (most of them in the PomaD and Dara group), 70 (63%) were classified as intermediate-risk, with a score of 4–7 (most of them in PomaD and KRd group), and 10 (9%) were classified as high-risk, with a score ≥8 (most of them in the PomaD group). All patients received a prophylaxis, consisting generally of low-doses of acetylsalicylic acid. VTE was recorded in 9% of our patients, all of them with an intermediate or high-risk IMPEDE score, treated with low doses aspirin (ASA). No VTE occurred in patients treated with daratumumab. Thus, our real-life experience documents that (1) in RRMM patients treated with continuative regimens of third line, the incidence of VTE is similar to the setting of newly-diagnosed patients; (2) many patients in real-life received prophylaxis with ASA, irrespective of the risk classification; (3) the IMPEDE VTE score seems to be more appropriate to define the risk categories. Randomized clinical trials are required to better define the VTE prophylaxis strategy in the RRMM setting.