Time-to-event surrogate end-points in multiple myeloma randomised trials from 2005 to 2019: A surrogacy analysis.

Use of surrogate end-points such as progression-free survival (PFS) and other time-to-event (TTE) end-points is common in multiple myeloma (MM) clinical trials. This systematic review characterises all published randomised controlled trials (RCTs) in MM using PFS or other TTE end-points between 2005 and 2019 and assesses strength of surrogacy of PFS for overall survival (OS). The association between OS hazard ratios (HRs) and PFS HRs was evaluated with linear regression, and the coefficient of determination with Pearson's correlation. We identified 88 RCTs of which 67 (76%) used PFS as the primary/co-primary end-point. One trial indicated whether progression was biochemical or clinical. Of the variance in OS, 39% was due to variance in PFS. Correlation between PFS and OS was weak (0.62, 95% confidence interval [CI] 0.38-0.78). In newly diagnosed MM, 43% of the variance in OS was due to changes in PFS. The correlation between PFS and OS was weak (0.65, 95% CI 0.30-0.84). In relapsed/refractory MM, 58% of the variance in OS was due to changes in PFS. Correlation between PFS and OS was medium (0.76, 95% CI 0.42-0.91). We demonstrate that PFS and progression characteristics are characterised poorly in MM trials and that PFS is a poor surrogate for OS in MM.

Attrition and withdrawal in multiple myeloma randomized controlled trials: A systematic review.

OBJECTIVES: Patients with multiple myeloma (MM) enrolled in randomized control trials (RCTs) discontinue treatment for various reasons; however, no prior study has analyzed reasons for discontinuation. We performed a systematic review of MM RCTs to investigate reasons for treatment discontinuation, imbalances between trial cohorts, and reporting practices. METHODS: A comprehensive search for RCTs in MM from 2015 to 2021 identified 45 studies meeting inclusion criteria. RESULTS: Of 21 236 randomized patients, 10 161 (47.8%) discontinued therapy by primary endpoint ascertainment. Causes of discontinuation included progression (n = 4790; 22.6% of randomized patients); toxicity (n = 2569; 12.1%); patient/physician withdrawal (n = 1200; 5.7%) and death (n = 495; 2.3%). Of randomized patients, 20 914 (98.5%) were included in the RCT analysis. Imbalances of attrition, defined as trials with greater than 5% absolute difference in discontinuation rate for reasons other than death, progression, and toxicity between intervention and control arms, were found in 11 (24.4%) studies. CONCLUSIONS: Although progression is the most common reason for RCT treatment discontinuation in patients with MM, over 10% discontinued due to toxicity. Furthermore, 24.4% of trials showed substantial imbalances between trial cohorts; raising concern for informative censoring and emphasizes the importance of detailed characterization of withdrawal in MM RCTs.

Use of endpoints in multiple myeloma randomized controlled trials over the last 15 years: A systematic review.

Surrogate endpoints are being used more frequently in randomized controlled trials, even though they do not consistently corelate with patient outcomes. We systemically evaluated the use of surrogate endpoints in multiple myeloma randomized controlled trials over the past 15 years. We searched three databases (Pubmed, Embase, Cochrane) for multiple myeloma randomized controlled trials from January 1, 2005 to December 30, 2019. The primary outcome of our study was the proportion of randomized controlled trials that used overall survival as their primary endpoint. Secondary outcomes included the use of surrogate endpoints, and trends over time, and whether they differed based on study sponsorship. We included 151 randomized controlled trials in our analysis. The primary endpoint was overall survival (OS) in 17 (11.3%) of studies, progression free survival (PFS) or event-defined endpoints in 91 studies (60.3%) and response-based endpoints in 44 studies (29.1%). Quality of life was a primary endpoint in only three studies (2%). The use of OS as a primary endpoint decreased from 28.5% of trials from 2005 to 2009 to 5.5% from 2015 to 2019. There has been a decrease in the clinically meaningful endpoint of OS over the past 15 years in multiple myeloma randomized controlled trials. Use of quality of life as a primary endpoint remains exceedingly low. It remains paramount to recognize that the use of surrogate endpoints is imperfect, and care based upon them requires constant physician and patient re-analysis.

Alterations in chromosome 1q in multiple myeloma randomized clinical trials: a systematic review.

Extra copies of chromosome 1q21 (+1q: gain = 3 copies, amp >= 4 copies) are associated with worse outcomes in multiple myeloma (MM). This systematic review assesses the current reporting trends of +1q, the efficacy of existing regimens on +1q, and its prognostic implications in MM randomized controlled trials (RCTs). Pubmed, Embase and Cochrane Registry of RCTs were searched from January 2012 to December 2022. Only MM RCTs were included. A total of 124 RCTs were included, of which 29 (23%) studies reported on +1q. Among them, 10% defined thresholds for +1q, 14% reported survival data separately for gain and amp, and 79% considered +1q a high-risk cytogenetic abnormality. Amongst RCTs that met the primary endpoint showing improvement in progression free survival (PFS), lenalidomide maintenance (Myeloma XI), selinexor (BOSTON), and isatuximab (IKEMA and ICARIA) were shown to improve PFS for patients with evidence of +1q. Some additional RCT's such as Myeloma XI+ (carfilzomib), ELOQUENT-3 (elotuzumab), and HOVON-65/GMMG-HD4 (bortezomib) met their endpoint showing improvement in PFS and also showed improvement in PFS in the +1q cohort, although the confidence interval crossed 1. All six studies that reported HR for +1q patients vs. without (across both arms) showed worse OS and PFS for +1q. There is considerable heterogeneity in the reporting of +1q. All interventions that have shown to be successful in RCTs and have clearly reported on the +1q subgroup have shown concordant direction of results and benefit of the applied intervention. A more standardized approach to reporting this abnormality is needed.

Incidence of second primary malignancies in patients with multiple myeloma receiving anti-CD38 monoclonal antibodies: A systematic review and meta-analysis.

Anti-CD38 monoclonal antibodies (mAbs) are commonly used for treating newly diagnosed and relapsed/refractory (r/r) multiple myeloma (MM). However, concerns have been raised about the occurrence of second primary malignancies (SPMs) in patients receiving anti-CD38 mAbs. Assessing the safety data for rare adverse events like SPMs is challenging because individual clinical trials are typically focused on the primary endpoint. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) published between January 2005 and April 2022, including patients with newly diagnosed or r/r MM. Our aim was to compare SPM rate with the use of anti-CD38 mAb-based regimens with other anti-myeloma regimens. After a median follow-up of 35.3 months (range: 8.2-56.2), we found that exposure to anti-CD38 mAbs was associated with an increased risk of developing SPMs compared to the control group (6.8% vs. 5.2%; Peto odds ratio [OR]: 1.53 [95% confidence interval (CI): 1.20-1.95]; I2= 0%, p-value for heterogeneity= 0.44). This increased risk was primarily driven by non-melanoma cutaneous cancers (92 vs. 47; Peto OR: 1.77 [95% CI: 1.25-2.51]; I2 = 0%, p-value for heterogeneity = 0.54). However, there was no significant difference in the incidence of solid tumors (including malignant melanoma) (OR: 1.28 [95% CI: 0.85-1.95]) or hematologic SPMs (OR: 1.86; [95% CI: 0.81-4.27]). In conclusion, the use of anti-CD38 mAb-based combination regimens is associated with a higher risk of non-invasive cutaneous SPMs, but not solid tumors or hematologic SPMs. The increased occurrence of non-invasive cutaneous SPMs may be due to enhanced monitoring resulting from longer treatment duration with anti-CD38 mAbs.

Global Myeloma Trial Participation and Drug Access in the Era of Novel Therapies.

PURPOSE: The globalization of clinical trials has accelerated recent advances in multiple myeloma (MM). However, it is unclear whether trial enrollment locations are reflective of the global burden of MM and whether access to novel therapies is timely and equitable for countries that participate in those trials. METHODS: To assess this, we characterized where MM trials that led to US Food and Drug Administration (FDA) approvals were conducted and determined how often and quickly these drug regimens received approval in their participating trial countries on the basis of country income level and geographic region. RESULTS: A systematic review was conducted to identify all MM clinical trials that met their primary endpoint, enrolled patients outside the United States, and resulted in FDA approval from 2005 to 2019. A total of 18 pivotal MM clinical trials were identified. High-income countries enrolled patients in 100% (18/18) of the trials identified, whereas upper-middle and lower-middle-income countries were represented in 61% (11/18) and 28% (5/18) of trials, respectively. No patients from low-income countries were enrolled. One trial enrolled patients in sub-Saharan Africa, and no trials enrolled patients in South Asia/Caribbean. For drugs/regimens that were approved in their participating countries, the median time from FDA approval to approval was 10.9 months. There were no drugs approved in lower-middle-income trial countries. MM trials leading to FDA approval are generally run in high-income, European, and Central Asian countries. CONCLUSION: There are substantial disparities in where novel therapies are evaluated and where they are ultimately approved for use on the basis of income level and geography.

Reporting of Postprotocol Therapies and Attrition in Multiple Myeloma Randomized Clinical Trials: A Systematic Review.

Importance: A thorough understanding of the optimal role and sequence of agents for treatment of multiple myeloma (MM) requires knowledge of the use and rate of postprotocol therapies in randomized clinical trials (RCTs). Objectives: To examine the proportion of MM RCTs that reported postprotocol therapies and, among those, the percentage of patients who received no further therapy and how treatments differed between the control and intervention arms. Evidence Review: The reporting of postprotocol therapies was systematically assessed in published MM RCTs using 3 databases (PubMed, Embase, and Cochrane Registry of Controlled Trials) for MM RCTs from January 1, 2005, to December 30, 2019. All MM RCTs were included, and all other studies, such as editorials, nonrandomized studies, and review articles, were excluded. Findings: A total of 103 RCTs were identified (47 251 patients); of these, 45 (43.7%) reported subsequent treatments in that publication or in any subsequent publication. Trials funded by pharmaceutical companies (26 of 47 [55.3%]) were more likely to report subsequent treatments than cooperative group studies (19 of 56 [33.9%]) (χ21,103 = 4.8; P = .03). Differences were found in the treatments received between the intervention and control arms of RCTs. When data were reported, 5150 of 9351 patients (54.9%) in RCTs of newly diagnosed MM and 2197 of 4501 patients (48.8%) in RCTs of relapsed/refractory MM received any subsequent therapy. Conclusions and Relevance: Postprotocol therapies in MM RCTs are often not reported and, when they are, many patients receive no further therapy. Reporting guidelines for postprotocol therapies are needed.

Quality of control groups in randomised trials of multiple myeloma enrolling in the USA: a systematic review.

To our knowledge, no study has evaluated the quality of control groups in randomised controlled trials of multiple myeloma. We aimed to do a systematic review of randomised controlled trials of multiple myeloma to ascertain the quality of the control groups used. PubMed (MEDLINE), Embase, Cochrane Controlled Register of Trials, and CinicalTrials.gov were searched for articles of randomised controlled trials of multiple myeloma based in the USA that initiated participant enrolment between Jan 1, 2010, and June 30, 2020. A control group regimen was considered to be inferior if a previous randomised controlled trial had shown an improved progression-free survival versus the control group before enrolment. Of 49 identified randomised controlled trials, seven (14%) began enrolling patients into inferior control groups after an existing superior regimen to the control had already been published. Nine (18%) of the 49 trials continued enrolment on substandard control groups after data emerged during the study enrolment period. The median time that newer data emerged regarding inferiority of the control group from the time a trial first enrolled a patient was 13 months (IQR 8-29 months). 12 (75%) of these 16 randomised controlled trials are published, and nine (75%) of the 12 published trials had overlapping investigators with trials that had previously shown the inferiority of the control group being used. Greater scrutiny on the quality of control groups in randomised controlled trials of multiple myeloma is needed.

Renal insufficiency in multiple myeloma: a systematic review and meta-analysis of all randomized trials from 2005-2019.

Clinical trials may be inconsistent in their enrollment and reporting of patients with multiple myeloma (MM) who have renal insufficiency (RI). We performed a systematic review of all MM randomized clinical trials (RCT) from 2005-2019 to evaluate reporting of prevalence, eligibility criteria and outcomes of patients with RI and MM. One-hundred and twenty-three RCTs were included. Only 30% of studies clearly reported on the proportion of patients who had RI. Only 68.2% reported eligibility criteria pertaining to RI, with no uniformity in the reported criteria. The relative risk (RR) of disease progression or death in patients with RI was higher than those without, RR of 1.20 (1.003-1.431) for relapsed/refractory and 1.07 (1.001-1.046) for newly diagnosed. There is inconsistent reporting and enrollment of patients with RI on MM RCT's. We advocate for higher enrollment of patients with RI and transparent reporting of their eligibility criteria and outcomes.