Neutropenia, a common side effect in cancer treatments, occurs when the number of neutrophils (a type of white blood cell) is below 1500. A study presented at the 2023 San Antonio Breast Cancer Symposium investigated the incidence of neutropenia in patients treated with sacituzumab govitecan (SG) and the role of granulocyte colony-stimulating factor (G-CSF) in managing these cases. The use of G-CSF, which is known to stimulate the bone marrow to produce more white blood cells, was evaluated for its impact on the duration of therapy (DOT) among these patients.

For their study, Vijay Gorantla, MD, PhD, University of Pittsburgh Medical Center, and colleagues utilized the Integra Connect PrecisionQ database, which contains records of over 2 million cancer patients across 500 different care centers, to determine the occurrence of neutropenia in patients treated with SG and the usage of G-CSF in those with neutropenia, and to compare the DOT between patients who received G-CSF and those who did not. To analyze the DOT, only patients with a follow-up duration of 12 months or more were considered. The SG patient data was analyzed for treatments given up until May 31, 2023. The authors used the Wilcoxon Rank Sum test to compare the median DOT between patients. They also performed a descriptive analysis to summarize patient demographic statistics.

The assessment identified a total of 447 patients who had been treated with SG. The average age of these patients at the start of treatment was 58.5 (median age of 60). Racially, 15% identified as Black or African American and 69% identified as White or Caucasian. Of the total 447 patients treated with SG, an alarmingly high percentage—98% (438 patients)—developed neutropenia while being treated. In terms of management, the study found that among the patients who developed neutropenia, 61% received G-CSF, while 39% did not. For patients who had at least 12 months of follow up (330 of the 447 patients), the median DOT was 119.5 days.

When the researchers delved into the details of how G-CSF usage may have affected this DOT, they found differences based on whether the patients received or did not receive the G-CSF treatment for neutropenia. Among the 204 patients who did receive a G-CSF, the median DOT increased to 147 days. However, for the 126 patients with neutropenia who did not receive G-CSF, their median DOT was notably shorter at only 97 days. The difference in these DOT measures was verified to be statistically significant (p < 0.001), per the Wilcoxon Rank Sum test.

The results showed that the patients treated with SG who also received G-CSF had longer DOT compared to their counterparts who did not receive G-CSF. Furthermore, nearly 40% of patients who developed neutropenia on SG did not receive G-CSF. This raises the possibility of improving patient management by increasing G-CSF utilization, which could extend patients’ time on therapy and potentially delay disease progression.

The study concluded that these findings mandate further research on prophylactic G-CSF usage in the management of patients receiving SG. Further clinical guidance may be necessary to establish best practices for managing patients on SG, ensuring that the advantages seen from G-CSF treatment in this study can be harnessed for all relevant patients.

Gorantla V, Alwon E, Gart M, et al. Utilization of Granulocyte Colony-Stimulating Factor (GCSF) in the Management of Patients (pts) on Sacituzumab Govitecan-hziy (SG) and Impact on Duration of Therapy (DOT). Presented at: the 2023 San Antonio Breast Cancer Symposium; December 5-9, 2023; San Antonio, TX, and virtual; Abstract PO2-18-02.