Clinical Outcomes Associated With Chronic Kidney Disease in Elderly Medicare Patients With Multiple Myeloma.

BACKGROUND

Chronic kidney disease (CKD) is common in patients with multiple myeloma (MM) and is associated with a poor prognosis. We assessed CKD-associated clinical outcomes among elderly patients with MM initiating chemotherapy in the United States.

MATERIALS AND METHODS

We identified elderly Medicare beneficiaries (≥66 years) diagnosed with MM who initiated first-line therapy from 2008 to 2014. We identified CKD using diagnosis codes. We followed patients for death, time to next treatment (TTNT), and myeloma-defining events (anemia, hypercalcemia, skeletal-related events, progression to/of CKD) until September 30, 2015. We estimated overall survival, TTNT, and cumulative incidence of myeloma-defining events using the Kaplan-Meier method and risk of CKD-associated outcomes using Cox proportional hazards models, adjusting for demographics and comorbid conditions.

RESULTS

Of 22,484 included patients, 8704 (39%) had CKD at first-line therapy initiation. Compared with patients without CKD, patients with CKD had shorter median overall survival (2.1 vs. 3.6 years) and median TTNT (10.0 vs. 12.4, 9.7 vs. 11.2, 8.3 vs. 9.2, and 6.9 vs. 8.3 months at first- to fourth-line therapy). Probability of CKD progression for patients at stages 1 to 5 was higher than the probability of developing CKD for patients without CKD (3-year cumulative incidence [95% confidence interval, CI], 47% [45-48%] vs. 27% [24-26%]). Adjusted hazard ratios for CKD versus non-CKD were: all-cause death, 1.23 (95% CI, 1.18-1.28); anemia, 1.34 (95% CI, 1.24-1.45); hypercalcemia, 1.23 (95% CI, 1.09-1.38); skeletal-related events, 0.85 (95% CI, 0.90-0.91); and TTNT, from 1.03 (95% CI, 0.96-1.10) at third-line therapy to 1.15 (95% CI, 1.04-1.27) at fourth-line therapy.

CONCLUSION

Data from the study suggest that CKD-associated clinical burden is substantial in elderly patients with MM.