Updated Meta-Analysis of Randomized Controlled Trials to Evaluate the Incidence of Infection and Pneumonia in Patients with Multiple Myeloma Treated with Daratumumab

Introduction:

Multiple myeloma is a hematologic cancer of plasma cell, a blood cell which normally produce antibodies, and accounts for approximately 13% of all hematologic malignancies. Daratumumab is a human anti CD38 IgGκ monoclonal antibody with a well characterized mechanism of action via direct antitumor effects and an immunomodulatory component and the incorporation of daratumumab to standard multiple myeloma regimen has shown to significantly improve response rates and survival, with notable toxicities. We performed a combined analysis of randomized controlled trials (RCT) to determine the risk of infection and pneumonia in patients with multiple myeloma treated with daratumumab.

Methods:

We systematically conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts from inception through June 2019. Phase III RCTs utilizing daratumumab in patients with multiple myeloma that mention infection including pneumonia as adverse effects were incorporated in the analysis. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR), and risk difference (RD) with 95% confidence interval (CI). Heterogeneity was assessed with Cochran's Q- statistic. Random effects model was applied.

Results:

A total of 3,547 patients with multiple myeloma from 5 phase III RCTs were eligible. Studies compared daratumumab (D) + bortezomib (V) + melphan (M) + prednisone (P) vs VMP, D + lenalidomide (R) + dexamethasone (d) vs Rd, DVd vs Vd and DVd + thalidomide (T) vs VTd. The randomization ratio was 1:1 in all studies. Daratumumab was utilized in relapsed and refractory multiple myeloma in the POLLUX study (n= 564) and the CASTOR study (n= 480) and as first-line treatment for patients with multiple myeloma in the ALCYONE study (n= 700), the CASSIOPEIA study (n= 1085) and the MAIA study (n= 737). The I² statistic for heterogeneity was 35, suggesting some heterogeneity among RCT. The incidence of any-grade infection was 58.01% in study group vs 48.06 % in control group (RR, 1.21; 95% CI: 1.12 - 1.31; P < 0.0001). High-grade infection rate was 5.46% higher in daratumumab group compared to control arm (RR, 1.27; 95% CI: 1.13 - 1.44; P = 0.0001). Any-grade pneumonia was reported in 12.58% in study arm versus 7.72%% in control group with RR of 1.63 (95% CI: 1.08 - 2.45; P = 0.02). High-grade pneumonia was 8.47% in study group versus 5.52% in control arm (RR, 1.51; 95% CI: 0.97 - 2.35; P = 0.07). The RR for high-grade pneumonia was statistically significant at 2.07 (95% CI: 1.50 - 2.85; P < 0.0001) in a subset of newly diagnosed multiple myeloma patients treated with daratumumab (n= 2503).

Conclusions:

The addition of daratumumab to standard multiple myeloma regimen contributed to higher incidence of all grades of infection and any-grade pneumonia, with RR of 1.27 for high-grade infection and RR of 1.63 for any-grade pneumonia. However, high-grade pneumonia was only found to be significant in a subset of patients with newly diagnosed multiple myeloma treated with daratumumab, with RR of 2.07. Timely intervention with proper supportive care is required.