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.

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.

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.

Introduction

Chimeric antigen receptor T-cell therapy (CART) has revolutionised treatment of haematological malignancies; however, current reporting uses a modified intention-to-treat analysis (mITT) which over-estimates efficacy. We assessed what proportion of CD19 and B-cell maturation antigen (BCMA) CART trials report the number of patients not receiving CART after being enrolled by performing meta-analysis of the mITT and intention-to-treat (iTT) overall response rate (ORR).

Methods

PubMed/MEDLINE, EMBASE and Cochrane databases were searched. All prospective clinical trials of CD19 and BCMA-targeting CART enrolling two or greater patients from 1st January 2013 to 1st November 2020 were included.

Results

A total of 28 BCMA CART and 74 CD19 CART trials were identified. These included 10 BCMA CART (35.7%) and 52 (70.2%) CD19 CART trials reporting total number of patients enrolled and number of patients treated with CART. For this cohort of trials, the mITT ORR for BCMA CART was 78.0% (95% confidence interval (CI) = 67.0-89.0%), and the iTT ORR was 70.0% (95% CI = 59.0-80.0%). For CD19 leukaemia CART, the mITT ORR was 87.2% (95% CI = 83.1-91.2), and the iTT ORR was 74.9 (95% CI = 64.8-85.0). For CD19 lymphoma CART, the mITT ORR was 70.7% (95% CI = 63.9-77.5), and the iTT ORR was 58.7% (95% CI = 49.7-67.7).

Conclusion

Across BCMA and CD19 CART trials, there is a difference of up to 8-12% in the ORR between modified and iTT analyses and a paucity of information regarding reasons why patients did not receive the intended study treatment.

Background

As the landscape of haematological malignancies dramatically changes due to diagnostic and therapeutic advances, it is important to evaluate trends in clinical trial designs. The objective of our study was to describe the design of clinical trials for five common haematological malignancies with respect to randomisation and end-points. We also aimed to assess trends over time and examine the relationships of funding source and country of origin to proportions of randomisation and utilisation of clinical end-points.

Methods

This systematic review identified haematological malignancy clinical trials starting in 2015-2020 registered at ClinicalTrials.gov as of 20th February 2021. Trial-related variables including randomisation status, type of primary end-point, and both projected and actual enrolment numbers were captured. Clinical end-points were defined as overall survival and quality of life, while surrogate end-points included all other end-points.

Results

Of 2609 relevant trials included in this analysis, only one-fifth were randomised (538, 21%), with a significant decrease in the proportion of randomised clinical trials from 26% of trials in 2015 to 19% in 2020 (p < 0.00001). Between the years 2015 and 2020, the proportion of randomised trials for all haematological malignancies using primary surrogate end-points remained relatively consistent, ranging from 84% in 2015 to 78% in 2020 (p = 0.352). Overall, only 15% of trials utilised primary end-points of overall survival or quality of life in a randomised design.

Conclusions

This systematic review of haematological malignancy trials found that the majority of trials are non-randomised and that there has been an increase in the ratio of non-randomised to randomised studies over time. The vast majority of randomised haematological malignancy trials use surrogate primary end-points.

BACKGROUND: On the basis of the DREAMM-2 study (ClinicalTrials.gov identifier NCT03525678), single-agent belantamab mafodotin (belamaf) was approved for patients with relapsed or refractory multiple myeloma (RRMM) who received ≥4 prior therapies, including anti-CD38 therapy. The authors investigated longer term efficacy and safety outcomes in DREAMM-2 after 13 months of follow-up among patients who received belamaf 2.5 mg/kg. METHODS: DREAMM-2 is an ongoing, phase 2, open-label, 2-arm study investigating belamaf (2.5 or 3.4 mg/kg) in patients with RRMM who had disease progression after ≥3 lines of therapy and were refractory to immunomodulatory drugs and proteasome inhibitors and refractory and/or intolerant to an anti-CD38 therapy. The primary outcome was the proportion of patients that achieved an overall response, assessed by an independent review committee. RESULTS: As of January 31, 2020, 10% of patients still received belamaf 2.5 mg/kg. Thirty-one of 97 patients (32%; 97.5% confidence interval [CI], 21.7%-43.6%) achieved an overall response, and 18 responders achieved a very good partial response or better. Median estimated duration of response, overall survival, and progression-free survival were 11.0 months (95% CI, 4.2 months to not reached), 13.7 months (95% CI, 9.9 months to not reached), and 2.8 months (95% CI, 1.6-3.6 months), respectively. Response and survival outcomes in patients who had high-risk cytogenetics or renal impairment were consistent with outcomes in the overall population. Outcomes were poorer in patients with extramedullary disease. In patients who had a clinical response and prolonged dose delays (>63 days; mainly because of corneal events), 88% maintained or deepened responses during their first prolonged dose delay. Overall, there were no new safety signals during this follow-up. CONCLUSIONS: Extended follow-up confirms sustained clinical activity without new safety signals with belamaf in this heavily pretreated patient population with RRMM.

The randomized, phase 2 GRIFFIN study (NCT02874742) evaluated daratumumab plus lenalidomide/bortezomib/dexamethasone (D-RVd) in transplant-eligible newly diagnosed multiple myeloma (NDMM). We present final post hoc analyses (median follow-up, 49.6 months) of clinically relevant subgroups, including patients with high-risk cytogenetic abnormalities (HRCAs) per revised definition (del[17p], t[4;14], t[14;16], t[14;20], and/or gain/amp[1q21]). Patients received 4 induction cycles (D-RVd/RVd), high-dose therapy/transplant, 2 consolidation cycles (D-RVd/RVd), and lenalidomide±daratumumab maintenance (≤ 2 years). Minimal residual disease-negativity (10-5) rates were higher for D-RVd versus RVd in patients ≥ 65 years (67.9% vs 17.9%), with HRCAs (54.8% vs 32.4%), and with gain/amp(1q21) (61.8% vs 28.6%). D-RVd showed a trend toward improved progression-free survival versus RVd (hazard ratio [95% confidence interval]) in patients ≥ 65 years (0.29 [0.06-1.48]), with HRCAs (0.38 [0.14-1.01]), and with gain/amp(1q21) (0.42 [0.14-1.27]). In the functional high-risk subgroup (not MRD negative at the end of consolidation), the hazard ratio was 0.82 (0.35-1.89). Among patients ≥ 65 years, grade 3/4 treatment-emergent adverse event (TEAE) rates were higher for D-RVd versus RVd (88.9% vs 77.8%), as were TEAEs leading to discontinuation of ≥ 1 treatment component (37.0% vs 25.9%). One D-RVd patient died due to an unrelated TEAE. These results support the addition of daratumumab to RVd in transplant-eligible patients with high-risk NDMM. Video Abstract.

In the MASTER study (NCT03224507), daratumumab+carfilzomib/lenalidomide/dexamethasone (D-KRd) demonstrated promising efficacy in transplant-eligible newly diagnosed multiple myeloma (NDMM). In GRIFFIN (NCT02874742), daratumumab+lenalidomide/bortezomib/dexamethasone (D-RVd) improved outcomes for transplant-eligible NDMM. Here, we present a post hoc analysis of patients with high-risk cytogenetic abnormalities (HRCAs; del[17p], t[4;14], t[14;16], t[14;20], or gain/amp[1q21]). Among 123 D-KRd patients, 43.1%, 37.4%, and 19.5% had 0, 1, or ≥2 HRCAs. Among 120 D-RVd patients, 55.8%, 28.3%, and 10.8% had 0, 1, or ≥2 HRCAs. Rates of complete response or better (best on study) for 0, 1, or ≥2 HRCAs were 90.6%, 89.1%, and 70.8% for D-KRd, and 90.9%, 78.8%, and 61.5% for D-RVd. At median follow-up (MASTER, 31.1 months; GRIFFIN, 49.6 months for randomized patients/59.5 months for safety run-in patients), MRD-negativity rates as assessed by next-generation sequencing (10-5) were 80.0%, 86.4%, and 83.3% for 0, 1, or ≥2 HRCAs for D-KRd, and 76.1%, 55.9%, and 61.5% for D-RVd. PFS was similar between studies and superior for 0 or 1 versus ≥2 HRCAs: 36-month PFS rates for D-KRd were 89.9%, 86.2%, and 52.4%, and 96.7%, 90.5%, and 53.5% for D-RVd. These data support the use of daratumumab-containing regimens for transplant-eligible NDMM with HCRAs; however, additional strategies are needed for ultra-high-risk disease (≥2 HRCAs). Video Abstract.