Real-world incidence of febrile neutropenia despite primary prophylaxis with pegylated G-CSF: a prospective single centre cohort study from India

Background Contemporary trials report febrile neutropenia (FN) rates of 1–2% with primary pegylated G-CSF prophylaxis, but real-world outcomes from low- and middle-income countries (LMICs) remain poorly documented, especially regarding the role and impact of rescue short-acting G-CSF after breakthrough FN. Methods Prospective single-arm cohort study (CTRI/2024/09/073887) of 125 adult patients receiving first-line chemotherapy with primary peg-G-CSF (6 mg SC single dose) at a tertiary cancer centre in India. Primary endpoint was incidence of FN. Secondary endpoints included hospitalisation, chemotherapy modifications, mortality, costs, and detailed utilisation of rescue short-acting G-CSF. Results FN occurred in 14/125 patients (11.2%; 95% CI 6.3–18.1%), generating 19 hospital admissions (recurrent FN in 4 patients). The observed incidence was significantly higher than the expected 1% (one-sample proportion test, p < 0.001). FN rates were similar between high-risk (13.0%) and intermediate-risk patients (10.1%) (p = 0.70). Univariate and multivariable analyses did not identify significant independent predictors of FN. All 14 FN patients received rescue short-acting G-CSF (median 5 doses/episode). Among FN cases, 10 (71.4%) required chemotherapy dose reductions, 2 (14.3%) had regimen changes, 1 (7.1%) discontinued chemotherapy, and 1 (7.1%) died from FN-related sepsis. Median hospital stay per episode was 5 days; total direct cost for 19 episodes was ₹6,01,154 (≈ US$7,200). No serious adverse events were attributed to rescue G-CSF (mild bone pain in 21.4%). Conclusions In routine Indian oncology practice, FN incidence despite primary peg-G-CSF prophylaxis is approximately 11%—substantially higher than contemporary trials—with similar rates across risk categories. This breakthrough FN has major clinical and economic consequences. Rescue short-acting G-CSF was universally used and safe. This first prospective LMIC study highlights real-world effectiveness gaps and the need for enhanced vigilance and supportive strategies in resource-constrained settings.