Primary G-CSF prophylaxis in sacituzumab govitecan-treated mTNBC: real-world evidence from a multinational CEBCC-102 cohort.

BACKGROUND

Sacituzumab govitecan (SG) is a key treatment for metastatic triple-negative breast cancer (mTNBC). Neutropenia is a common toxicity, and the optimal use of G-CSF (primary prophylaxis versus reactive administration) remains uncertain. We evaluated the association of primary G-CSF prophylaxis with clinical outcomes and treatment-related toxicities.

METHODS

We conducted a multinational retrospective real-world cohort study of 303 patients with mTNBC treated with SG in the second or a later line. Efficacy endpoints included progression-free survival (PFS) and overall survival (OS), analyzed using the Kaplan-Meier method. Adverse events were assessed according to CTCAE criteria.

RESULTS

Of 303 patients, 100 were included in the primary prophylaxis group and 203 in the no primary prophylaxis group. Median PFS was 4.2 months in the primary prophylaxis group versus 5.1 months in the no primary prophylaxis group (p = 0.66), with 6-month PFS rates of 38.5% vs. 42.1%, respectively. Median OS was 10.9 vs. 11.6 months (p = 0.95), with 12-month OS rates of 44.9% vs. 47.1%. The frequencies of the recorded individual AEs were similar between groups, apart from grade 3-4 neutropenia, which was less frequent in the primary prophylaxis group (33.0% vs. 50.7%, p = 0.005). Febrile neutropenia occurred in 4.0% vs. 4.4% of patients (p = 1.00). Other recorded AEs (anemia, diarrhea, nausea, vomiting, alopecia) were comparable. Dose reductions due to toxicity were similar (36.0% vs. 38.4%, p = 0.71). In the no primary prophylaxis group, 74.4% subsequently received secondary G-CSF.

CONCLUSIONS

In this retrospective real-world cohort, primary G-CSF prophylaxis was associated with a lower frequency of grade 3-4 neutropenia. No statistically significant differences in PFS, OS, or febrile neutropenia were observed between groups. These findings support a risk-adapted rather than universal approach to primary G-CSF prophylaxis.