Real world Italian experience of pomalidomide plus low-dose dexamethasone in the relapsed and refractory myeloma setting: extended follow-up of a retrospective multicenter study by the 'Rete Ematologica Pugliese E Basilicata'

Beyond Clinical Trials in Patients With Multiple Myeloma: A Critical Review of Real-World Results

The current strategies for the treatment of multiple myeloma (MM) have improved, thanks to effective drug classes and combination therapies, for both the upfront and relapsed settings. Clinical trials for newly diagnosed transplant-ineligible patients led to the approval of immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) in combination with anti-CD38 monoclonal antibodies (mAbs), to be administered during the induction phase before transplantation and during maintenance treatment, with lenalidomide recommended until relapse. In relapsed/refractory patients, the complex treatment scenario currently includes several options, such as triplets with anti-CD38 mAbs plus IMiDs or PIs, and novel targeted molecules. Comparisons among clinical trials and real-world data showed a good degree of reproducibility of some important results, particularly in terms of overall response rate, progression-free survival, and overall survival. This may help clinicians towards a proper selection of the best treatment options, particularly in real-world settings. However, as compared with the management of real-world settings, clinical trials have some pitfalls in terms of outcome and especially in terms of safety and quality of life. In fact, trials include younger and presumably healthier patients, excluding those with worst clinical conditions due to MM features (e.g., renal insufficiency or bone disease, which can impair the performance status) and comorbidities (e.g., cardiac and pulmonary disease), thus resulting in a possible lack of representativeness of data about the patients enrolled. In this review, we analyze comparable and discrepant results from clinical trials vs. real-world settings published in the last 10 years, focusing on different drugs and combinations for the treatment of MM and providing an overview of treatment choices.

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).

Pomalidomide and Dexamethasone Are Effective in Relapsed or Refractory Multiple Myeloma in a Real-Life Setting: A Multicenter Retrospective Study in Taiwan

Background

The therapeutic options of relapsed or refractory multiple myeloma (RRMM) remain a challenge. The MM-003 trial demonstrated that RRMM patients treated with pomalidomide and dexamethasone (Pom/Dex) have better progression-free survival (PFS) than those treated with high-dose dexamethasone alone. However, the real-world effectiveness of Pom/Dex in these patients in Taiwan remains unclear.

Methods

This multicenter, registry-based study retrospectively reviewed the medical records of 49 consecutive patients undergoing Pom/Dex treatment for RRMM. We investigated the overall response rate (ORR) and PFS in these patients. The patients were stratified into two groups: those who received two (n=33) and those who received more than two (n=16) prior lines of treatment according to the numbers of regimens before Pom/Dex therapy. The differences in ORR and PFS between these two groups were further analyzed. We also analyzed factors attributed to disease progression.

Results

The ORR was 47.7%, and the median PFS was 4.0 months (range, 0.1−21.1). Patients who received two prior lines of treatment had a higher ORR than those who received more than two prior lines of treatment (55.2% vs. 33.3%; p=0.045). The median PFS of these groups was 4.8 and 3.9 months, respectively (p=0.805). Primary lenalidomide refractoriness reduced the risk of myeloma progression following Pom/Dex treatment (hazard ratio, 0.14; p=0.001).

Conclusions

The median PFS following Pom/Dex treatment in Taiwanese RRMM patients in a real-world setting was similar to that reported by the MM-003 trial. Primary lenalidomide refractoriness should not be an obstacle for Pom/Dex treatment in RRMM.

Pomalidomide Plus Low-Dose Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients: Results of the Real-World "POWERFUL" Study

The “POWERFUL” multicenter, retrospective, and prospective study investigated the effectiveness of pomalidomide plus low-dose dexamethasone (POM/LoDex) therapy in relapsed/refractory multiple myeloma in routine care in Greece. Ninety-nine eligible adult patients treated with POM/LoDex according to the approved label after having received ≥2 prior therapies, including lenalidomide and bortezomib, were consecutively enrolled between 16 November 2017 and 21 February 2019 in 18 hematology departments. Fifty patients (50.5%) started POM/LoDex as third-line treatment. During the treatment period (median: 8.3 months; range: 0.3–47.6 months), the median POM dose was 4 mg/day, and 31.3% of the patients received additional antimyeloma agents. The overall response rate was 32.3%. During a median follow-up period of 13.8 months (Kaplan–Meier estimate), the median progression-free survival (PFS) was 10.5 months (95% CI: 7.4–14.4). The PFS was not significantly different between patients receiving POM/LoDex in the third versus later line of therapy, nor between patients receiving concomitant antimyeloma therapy versus POM/LoDEx doublet. During the prospective safety data collection period (median: 7.6 months) among patients with prospective follow-up (N = 75), POM-related adverse event incidence rate was 42.7% (serious: 18.7%; grade  ≥  3 hematological POM-related adverse events: 8.0%). Only neutropenia (13.3%) was reported at a frequency ≥10%. In conclusion, in this real-world study, POM/LoDex displayed a long PFS with no new safety signals emerging.

Real-World Treatment of Patients With Relapsed/Refractory Myeloma

The continuous advances in the treatment landscape of multiple myeloma has led to the approval of several novel agents and their combinations that significantly improved patient outcomes. Despite their undoubtful effectiveness in the context of clinical trials, their impact on real-world (RW) clinical practice remains debatable. RW data on the role of novel agents and their combinations among patients with relapsed/refractory multiple myeloma have confirmed the efficacy of proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies. However, the magnitude of the benefit and the safety profile may differ among RW studies and between RW and pivotal clinical trials. Several variables may pertain to these observations and include patient selection, ethnicity, age, comorbidities, disease stage at diagnosis and at relapse, number of prior lines of therapy, disease subtype, presence of renal impairment, extramedullary disease, and cytogenetic abnormalities. All these contribute to a varying degree of disease and patient heterogeneity among the studies that may result in a differential treatment effect. The expertise of each medical center and the treatment setting in terms of availability and drug access are particularly important as well. Interestingly, RW observations may serve as proof of concept for designing novel clinical trials, as is the case with retreatment studies. In conclusion, clinical trial and RW data are complementary, and they should be considered to improve both clinical trial design and clinical practice.

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

Background: We retrospectively analysed relapsed/refractory MM (RRMM) patients treated with pomalidomide and dexamethasone (PomaD) either in real life, or previously enrolled in an interventional (STRATUS, MM-010) or currently enrolled in an observational study (MM-015) to provide further insights on safety and tolerability and clinical efficacy. Methods: Between July 2013 and July 2018, 76 RRMM patients (including 33 double refractory MM) received pomalidomide 4 mg daily given orally on days 1–21 of each 28-day cycle, and dexamethasone 40 mg weekly (≤75 years) or 20 mg weekly for patients aged > 75 years. In nine patients a third agent was added to increase the response: Cyclophosphamide (in two fit patients) or clarithromycin (in seven frail patients). Patients received subcutaneous filgrastim as part of the prophylaxis regimen for neutropenia. Results: A median number of six (range 2–21) PomaD cycles were given. The regimen was well tolerated with grade 3–4 haematological and non-haematological adverse events in 39 (51%) and 25 (33%) patients, respectively. In patients who developed serious AE, pomalidomide dose reduction (11%, 14%) or definitive discontinuation (18%, 23%) were applied. All patients have been evaluated for response within the first two cycles. The disease control rate (DCR), i.e., those patients that had a response equal or better than stable disease (≥ SD), was high (89%), with 44% overall response rate (ORR) after six cycles. The achieved best responses were complete remission (CR, 5%), very good partial remission (VGPR, 4%), partial remission (PR, 35%), minimal response (MR, 7%), and stable disease (SD, 38%). After a median follow up of 19.6 months, median progression free survival was 9.4 months, and overall survival (OS) was 19.02 months. Univariate analysis showed that double refractory patients, or who received more than three previous lines had shorter PFS. At 18 months, regardless of the depth of response, patients with a disease control of at least six months, defined as maintenance of a best clinical and/or biochemical response to treatment for almost six months, had prolonged PFS (35.3% versus 20.6%, p = 0.0003) and OS (81.2% versus 15.9%, p < 0.0001) Conclusions: Our findings indicate that PomaD is a safe and well-tolerated regimen in real-life, associated with prolonged PFS and OS with acceptable toxicity. Moreover, Pd induced disease control in most intensively pre-treated patients and some of them achieved longer PFS than that obtained with the previous treatment.