Does enrolment in clinical trials improve survival in patients with multiple myeloma?

Enrolment in clinical trials does not seem to increase survival among patients with multiple myeloma, a recent study has found.

“Patients enrolled in clinical trials underwent more lines of therapy, suggesting they may have had more treatment-resistant cancers,” the authors said. “A small survival benefit in this cohort may be obscured by the lack of difference in survival between trial and nontrial patients.”

A total of 1,285 patients receiving care for multiple myeloma at a National Cancer Institute-designated cancer centre from 2012 to 2018 were identified. Of these, 1,065 (83 percent) were nontrial and 220 (17 percent) were trial participants.

The authors used time-to-event analysis to adjust for baseline characteristics and account for clinical trial enrolment as a time-varying covariate. They also analysed propensity-matched cohort of trial and nontrial patients to reduce potential bias in observational data.

Compared with nontrial patients, trial participants were younger (mean age, 60 vs 63 years; p<0.001), underwent more lines of therapy (treatment lines ≥6, 39 percent vs 17 percent; p<0.001), and had more comorbidities.

Survival did not differ significantly between trial and nontrial participants (hazard ratio [HR], 1.34, 95 percent confidence interval [CI], 0.90–1.99) or between propensity-matched trial and nontrial participants (205 in each cohort; HR, 1.36, 95 percent CI, 0.83–2.23) after controlling for baseline characteristics and clinical trial enrolment as a time-varying covariate.

Results from overall analyses were consistent with those from subgroup analyses by lines of therapy.

Survival also did not significantly differ by race/ethnicity (logrank p=0.09). However, nontrial Black/Hispanic patients had a significantly higher risk of death than their White counterparts (HR, 1.76, 95 percent CI, 1.01–3.08).