Risk of chemotherapy-induced febrile neutropenia with same-day versus next-day pegfilgrastim prophylaxis among patients aged ≥65 years: a retrospective evaluation using Medicare claims

<p><b>Background:</b> Two recent evaluations reported that risk of febrile neutropenia (FN) may be higher when pegfilgrastim prophylaxis (PP) is administered on same day as chemotherapy rather than per recommendation (1–3 days following chemotherapy). Such evidence is based largely on the experience of younger privately insured adults and may not be generalizable to older patients in US clinical practice.</p> <p><b>Methods:</b> A retrospective cohort design and data from Medicare Claims Research Identifiable Files (January 2008–September 2015) were employed. Patients were aged ≥65 years, had breast cancer or non-Hodgkin’s lymphoma, received chemotherapy with intermediate/high risk for FN, and received PP in ≥1 cycle; cycles with PP were stratified based on administration day (same-day [“Day 0”] vs. 1–3 days following chemotherapy [“Days 1–3”]) and were pooled for analyses. Adjusted odds ratios (ORs) for FN during the cycle were estimated for patients who received PP on Day 0 versus Days 1–3.</p> <p><b>Results:</b> Study population included 65,003 patients who received PP in 261,184 cycles; in 5% of cycles, patients received PP on Day 0. Incidence proportion for FN in cycle 1 was 11.4% for Day 0 versus 8.4% for Days 1–3; adjusted OR was 1.4 (<i>p</i> < .001). Incidence proportion for FN when considering all cycles was 7.7% for Day 0 and 6.0% for Days 1–3; adjusted OR was 1.3 (<i>p</i> < .001). Adjusted ORs when considering all cycles and only inpatient FN episodes (1.3, <i>p</i> < .001) and the narrow definition for FN (1.5, <i>p</i> < .001) were similar.</p> <p><b>Conclusions:</b> Among Medicare patients receiving chemotherapy and PP in US clinical practice, PP was administered before the recommended timing in 5% of cycles and FN incidence was significantly higher in these cycles. Along with prior research, study findings support recently updated US practice guidelines indicating that PP should be administered the day after chemotherapy.</p

A within-trial cost-effectiveness analysis of panitumumab compared with bevacizumab in the first-line treatment of patients with wild-type <i>RAS</i> metastatic colorectal cancer in the US

<p><b>Aims:</b> This analysis investigated the cost-effectiveness of panitumumab plus mFOLFOX6 (oxaliplatin, 5-fluorouracil, and leucovorin) compared with bevacizumab plus mFOLFOX6 in the first-line treatment of patients with wild-type <i>RAS</i> metastatic colorectal cancer (mCRC).</p> <p><b>Materials and methods:</b> The cost-effectiveness analysis was developed from a third-party payer perspective in the US and was implemented using a partitioned survival model with health states for first-line treatment (progression-free), disease progression with and without subsequent active treatment, and death. Survival analyses of patients with wild-type <i>RAS</i> mCRC from the PEAK head-to-head clinical trial of panitumumab vs bevacizumab were performed to estimate time in the model health states. Additional data from PEAK informed the amount of each drug consumed, duration of therapy, subsequent therapy use, and toxicities related to mCRC treatment. Literature and US public data sources were used to estimate unit costs associated with treatment and duration of subsequent active therapies. Utility weights were calculated from patient-level data from panitumumab trials in the first-, second-, and third-line settings. A life-time perspective was taken with future costs and outcomes discounted at 3% per annum. Scenario, one-way, and probabilistic sensitivity analyses were performed.</p> <p><b>Results:</b> Compared with bevacizumab, the use of panitumumab resulted in an incremental cost of US $60,286, and an incremental quality-adjusted life-year (QALY) of 0.445, translating into a cost per QALY gained of US$135,391 in favor of panitumumab. Results were sensitive to wastage and dose rounding assumptions modeled.</p> <p><b>Limitations:</b> Progression-free and overall survival were extrapolated beyond the follow-up of the primary analysis using fitted parametric curves. Costs and quality of life were estimated from multiple and different data sources.</p> <p><b>Conclusions:</b> The efficacy of panitumumab in extending progression-free and overall survival and improving quality of life makes it a cost-effective option for first-line treatment of patients with wild-type <i>RAS</i> mCRC compared with bevacizumab.</p