Risk Factors for Palbociclib-Induced Early Developing Neutropenia in Patients with Hormone Receptor-Positive Metastatic Breast Cancer.

PURPOSE: This study aimed to determine the risk factors for palbociclib-induced grade 4 or grade 3 neutropenia (NP) requiring dose reduction or delayed treatment in patients with HR+/HER2-metastatic breast cancer in the first 3 cycles (early grade 3/4 NP) and whether the early developing grade 3/4 NP affects progression-free survival. METHODS: A retrospective study using electronic medical records was conducted on patients who received palbociclib for metastatic breast cancer between January 2018 and August 2022. The early grade 3/4 NP risk factors were evaluated with univariate and multivariable logistic regression analyses. In addition, the Kaplan-Meier method was used to estimate the median progression-free survival (PFS) to analyze the effect of early grade 3/4 NP on treatment. RESULTS: Out of the 264 patients included in this study, 173 (65.6%) experienced early grade 3/4 NP. A total of four models were applied for multivariable analysis to identify early grade 3/4 NP-developing factors. Low baseline ANC, WBC, PLT, and BSA were significant risk factors for early grade 3/4 NP; baseline ANC < 3700/mm3, WBC < 6.30 × 109/mm3, PLT < 230 × 109/mm3, and BSA < 1.58 m2 increased the risk by approximately 4.0-fold, 3.7-4.0-fold, 2.1-fold, and 2.0-fold, respectively. Early grade 3/4 NP did not affect PFS (p = 0.710), although patients with early grade 3/4 NP had more frequent dose reductions or treatment delays. CONCLUSIONS: Based on the results, low baseline ANC, WBC, PLT, and BSA were associated with early grade 3/4 NP. Patients with risk factors require careful monitoring, and this study is expected to help predict NP, which may appear in early treatment.

Factors affecting high-grade hepatotoxicity of tyrosine kinase inhibitors in cancer patients: a multi-center observational study.

PURPOSE: Although several studies have examined tyrosine kinase inhibitor (TKI)-induced hepatotoxicity, the majority of patients in those studies displayed low-grade (grade I-II) hepatotoxicity. The purpose of this study was to investigate factors affecting high-grade (grade III-IV) hepatotoxicity of TKIs. METHODS: This multi-center, retrospective study used individual patient data from five studies that examined factors affecting hepatotoxicity by TKIs (crizotinib, erlotinib, gefitinib, imatinib, and lapatinib). Odds ratio (OR) and adjusted OR (AOR) were estimated from univariate and multivariate analyses, respectively. RESULTS: Data from 1279 patients treated with TKIs were analyzed. The rate of patients who experienced high-grade hepatotoxicity after TKI administration was 5.5%. In multivariable analysis, H2 blockers and CYP3A4 inducers increased high-grade hepatotoxicity 2.2- (95% CI 1.255-3.944) and 3.3-fold (95% CI 1.260-8.698), respectively. Patients with liver metastasis revealed a 3.4-fold (95% CI 1.561-7.466) higher risk of high-grade hepatotoxicity. Among underlying malignancies, pancreatic cancer and other cancers including acute lymphoblastic leukemia increased the risk of high-grade hepatotoxicity by 2.6- and 24.3-fold, respectively, whereas breast cancer decreased the risk (AOR 0.3, 95% CI 0.106-0.852), compared to non-small cell lung cancer. In patients who administrated TKIs which form reactive metabolites, use of CYP3A4 inducers and liver metastasis increased incidence of high-grade hepatotoxicity by 3.0- and 2.3-fold, respectively. In patients with EGFR mutation, exon 19 deletion and use of proton pump inhibitors were risk factors for high-grade hepatotoxicity in addition to liver metastasis and use of H2 blockers. CONCLUSION: The use of H2 blockers, presence of liver metastasis, and CYP3A4 inducers were associated with high-grade hepatotoxicity of TKIs. In subgroup analyses, presence of exon 19 deletion, and/or proton pump inhibitors, was additional risk factors for high-grade hepatotoxicity in special patients and use of specific TKIs. Close liver function monitoring is recommended, especially in patients with liver metastasis or using H2 blockers or CYP3A4 inducers.

Risk factors associated with the incidence and time to onset of lapatinib-induced hepatotoxicity.

PURPOSE: Although lapatinib-induced hepatotoxicity can cause severe clinical complications in patients, the factors affecting hepatotoxicity have rarely been investigated. The purpose of this study was to investigate risk factors for hepatotoxicity and time to lapatinib-induced hepatotoxicity. METHODS: This retrospective study was performed on metastatic breast cancer patients treated with lapatinib. Various factors were evaluated for hepatotoxicity and time to hepatotoxicity, including sex, age, body weight, height, body surface area, underlying disease, smoking history, start dose of lapatinib, status of liver metastasis, and concomitant drugs. RESULTS: Among 159 patients, the percentage of patients with hepatotoxicity after lapatinib initiation was 57.9% (n = 92). Multivariate analysis showed that concomitant use of H2 blockers increased the incidence of hepatotoxicity by 2.3-fold. Patients who received CYP3A4 inducers had 3.1 times higher risk of hepatotoxicity incidence; the attributable risks of H2 blockers and CYP3A4 inducers were 56.7% and 68.1%, respectively. Use of H2 blockers increased the hazard of time to hepatotoxicity by 1.8-fold compared to non-use of H2 blockers. CONCLUSIONS: Our study demonstrated that concomitant use of H2 blockers and CYP3A4 inducers was associated with lapatinib-induced hepatotoxicity. Close liver function monitoring is recommended, especially in patients receiving H2 blockers or CYP3A4 inducers.