(Z) Incidence of Opportunistic Infections Among Patients with Multiple Myeloma: Real-World Evidence from a Large US National Claims Database

Publication Number: 316

Background: Individuals with multiple myeloma (MM) are susceptible to infections, including opportunistic, due to the underlying disease and antineoplastic therapy-induced immunosuppression.

Objectives: To evaluate the incidence of opportunistic infections, including Pneumocystis jirovecii pneumonia (PJP), cytomegalovirus (CMV), herpes zoster, and Epstein-Barr virus (EBV) infections, among newly diagnosed patients with MM, among those initiating a bortezomib-containing regimen, and among triple-class-exposed (TCE) patients, both with or without infection prophylaxis.

Methods: Five cohorts of adults aged ≥18 years with a confirmed diagnosis of MM were identified in IQVIA PharMetrics® Plus between January 2013 and September 2020: untreated, newly diagnosed patients; MM patients initiating a bortezomib-containing treatment regimen who received infection prophylaxis and those who did not; MM patients who were previously exposed to ≥1 immunomodulatory drug, ≥1 proteasome inhibitor, and ≥1 anti-CD38 (i.e., TCE) and did or did not receive prophylaxis. The index dates consisted of the first MM diagnosis for newly diagnosed patients, the date of the first respective pharmacy code for MM patients initiating bortezomib, the date of subsequent treatment initiation after patients were considered TCE, and the date of prophylaxis initiation among treated patients who received infection prophylaxis. The 30- and 180-day incidence rates were calculated per 1,000 patient-years and the Fisher’s exact test was used to estimate 95% confidence intervals.

Results: In total, there were 15,977 newly diagnosed MM patients, 10,244 bortezomib-exposed, and 2,106 were considered TCE. Among newly diagnosed MM patients, the incidence rates of opportunistic infections per 1,000 patient-years at 30 and 180 days were: CMV: 6.32 (2.73-12.45) and 8.34 (6.38-10.72), herpes zoster: 35.98 (26.04-48.47) and 47.35 (42.34-52.80), EBV: 0.00 (0.00-0.00) and 0.82 (0.30-1.78), and PJP: 3.15 (0.86-8.08) and 2.87 (1.77-4.38). At both 30 and 180 days, the incidence of CMV, herpes zoster, and PJP infections in bortezomib-exposed patients tended to be greater for patients not receiving infection prophylaxis compared to those receiving prophylaxis. Among TCE patients, no consistent pattern of rates of infection was observed in relation to the presence or absence of prophylaxis.

Conclusions: This study demonstrated that opportunistic infections frequently occur in MM patients, particularly herpes zoster, CMV, and PJP. Lower infection rates in patients who received both bortezomib treatment and infection prophylaxis underscore the need for infection prophylaxis after bortezomib treatment.