Patients with non-Hodgkin lymphoma or breast cancer with intermediate risk for febrile neutropenia (FN) maintain that risk even with pegfilgrastim prophylaxis, according to research presented by Weijia Wang, Associate Director, Health Economics and Outcomes Research at Sandoz, and colleagues at the National Comprehensive Cancer Network (NCCN) 2021 Virtual Annual Conference.

“[FN] is a major dose-limiting toxicity of myelosuppressive chemotherapy that can result in hospitalization, dose reductions or treatment delays and compromised clinical outcomes. [NCCN] guidelines recognize that the risk of developing FN is based on a regimen’s risk (high, intermediate, low) and patient-related risk factors,” the researchers wrote.

Using MarketScan Commercial and Medicare data, Mr Wang et al sought to estimate the link between demographics, comorbidities, chemotherapy regimens, and FN risk factors and the likelihood of developing FN during the first cycle among patients with NHL or breast cancer who received prophylactic pegfilgrastim from January 2017 to May 2018.

Patients were deemed eligible for inclusion in the study if they were continuously enrolled 6-months before and after the index pegfilgrastim prophylaxis date.

Ultimately, 4807 patients (mean age, 53.5 years) were identified, the majority (96.9%) of whom had breast cancer. Approximately 80% and 70% of these patients received regimens with a high risk for FN and had at least 1 risk factor for FN, respectively.

According to the investigators, the odds ratio for patients with 3 versus 0 risk factors for FN were 5.4, 5.6, and 6.5 for main, sensitive, and specific definitions, respectively (all P <.01). All definitions have previously been validated by Weycker et al (BMC Health Serv Res. 2013;13:60).

Furthermore, patients treated with intermediate-risk regimens had a higher likelihood of FN than those given high-risk regimens (odds ratio: 1.6, 1.7, 1.8 for main, sensitive, and specific definitions, respectively; all P <.05).

“Despite prophylaxis with pegfilgrastim, patients with multiple risk factors and those treated with chemotherapy regimens at intermediate risk of FN are still at risk of developing FN. This is not surprising, as growth factors do not completely ameliorate the risk of febrile neutropenia, but rather decrease it, and patients receiving intermediate risk FN chemotherapy regimens with multiple risk factors continue to be at risk, albeit less than expected without growth factor support,” Mr Wang and colleagues wrote.

“Real-world studies evaluating the comparative effectiveness of myeloid growth factors must apply statistical methods to mitigate bias by considering these variables when adjusting the cohorts,” they concluded.—Hina Porcelli

Wang W, Li E, Campbell K, et al. Febrile Neutropenia Outcomes Among Patients With Breast Cancer and Non-Hodgkin’s Lymphoma Receiving Pegfilgrastim Prophylaxis: A Real-World Analysis of Commercial and Medicare Claims From 2017-2018. Presented at: the NCCN 2021 Virtual Annual Conference; March 18-20,2021; Virtual. Abstract HSR21-073.