Longer duration of second-line therapy is strongly linked to improved 1-year overall survival in patients with relapsed and refractory multiple myeloma, according to findings from a real-world analysis.

The retrospective, observational study evaluated outcomes in 628 patients with multiple myeloma who relapsed after initial treatment. Parameswaran Hari, MD , of the Medical College of Wisconsin in Milwaukee and his colleagues sought to test the growing consensus that prolonged therapy is the best approach in a cohort of patients who received care in a routine setting and were older and had more comorbidities than patients in clinical trials.

The findings are published in Clinical Lymphoma, Myeloma & Leukemia .

Median overall survival was 41 months (95% confidence interval, 32.1-59.5) among the 628 relapsed/refractory patients who started second-line therapy. Each extra month of second-line therapy was associated with a reduced risk of death at 1 year (adjusted odds ratio, 0.78; 95% CI, 0.77-0.83; P less than .001). the median duration of second-line therapy for patients in the study was 6.9 months. When researchers extended the duration to 11 months, it was correlated with a 12.7% higher 1-year overall survival probability.

Age was an important factor in survival. The 1-year mortality was significantly lower in patients under 75 years (OR, 0.37; 95% CI, 0.20-0.68).

“Despite substantial heterogeneity in patient and disease characteristics and treatment patterns, the clinical benefit of continued longer-term therapy at relapse appears to be generalizable to patients receiving care in the routine care settings,” the researchers wrote.

Takeda funded the study and four of the authors are Takeda employees. Dr. Hari reported fees from Takeda and several other pharmaceutical companies.

SOURCE: Hari P et al. Clin Lymphoma Myeloma Leuk. 2018 Jan 5. doi: 10.1016/j.clml.2017.12.012 .