Analysis of Risk Factors for High-dose Cisplatin-induced Renal Impairment in Head and Neck Cancer Patients.

BACKGROUND/AIM: Concurrent chemoradiotherapy with high-dose cisplatin (CDDP-RT) is the standard therapy for advanced head and neck cancer; however, due to CDDP-induced renal impairment, dose reduction or discontinuation is frequently required. Therefore, the identification of risk factors for renal impairment is of importance to improve the efficacy and safety of CDDP-RT. PATIENTS AND METHODS: We retrospectively investigated risk factors for renal impairment in advanced head and neck cancer patients receiving CDDP-RT. Renal impairment was defined as a >25% decrease from baseline in estimated glomerular filtration rate within 14 days after CDDP administration in the first cycle. RESULTS: Of the 82 patients analyzed in this study, 21 (26%) patients developed renal impairment. Multivariate logistic regression analysis showed that concomitant use of a calcium channel blocker or lower hemoglobin levels significantly contributed to the increased risk of CDDP-induced renal impairment (odds ratio=3.60, 95% confidence interval=1.04-12.40; odds ratio=0.71, 95% confidence interval=0.50-0.99, respectively), while concomitant use of proton pump inhibitors was a factor associated with a decreased risk of CDDP-induced renal impairment (odds ratio=0.20, 95% confidence interval=0.04-0.86). CONCLUSION: Renal function of patients receiving calcium channel blocker or patients with lower hemoglobin levels should be monitored cautiously when receiving CDDP-RT.

Dose Individualization of Oral Multi-Kinase Inhibitors for the Implementation of Therapeutic Drug Monitoring.

Oral multi-kinase inhibitors have transformed the treatment landscape for various cancer types and provided significant improvements in clinical outcomes. These agents are mainly approved at fixed doses, but the large inter-individual variability in pharmacokinetics and pharmacodynamics (efficacy and safety) has been an unsolved clinical issue. For example, certain patients treated with oral multi-kinase inhibitors at standard doses have severe adverse effects and require dose reduction and discontinuation, yet other patients have a suboptimal response to these drugs. Consequently, optimizing the dosing of oral multi-kinase inhibitors is important to prevent over-dosing or under-dosing. To date, multiple studies on the exposure-efficacy/toxicity relationship of molecular targeted therapy have been attempted for the implementation of therapeutic drug monitoring (TDM) strategies. In this milieu, we recently conducted research on several multi-kinase inhibitors, such as sunitinib, pazopanib, sorafenib, and lenvatinib, with the aim to optimize their treatment efficacy using a pharmacokinetic/pharmacodynamic approach. Among them, sunitinib use is an example of successful TDM implementation. Sunitinib demonstrated a significant correlation between drug exposure and treatment efficacy or toxicities. As a result, TDM services for sunitinib has been covered by the National Health Insurance program in Japan since April 2018. Additionally, other multi-kinase targeted anticancer drugs have promising data regarding the exposure-efficacy/toxicity relationship, suggesting the possibility of personalization of drug dosage. In this review, we provide a comprehensive summary of the clinical evidence for dose individualization of multi-kinase inhibitors and discuss the utility of TDM of multi-kinase inhibitors, especially sunitinib, pazopanib, sorafenib, and lenvatinib.

Severe Skin Disorders Due to Sorafenib Use After Nivolumab Treatment in Renal Cell Carcinoma Patients.

BACKGROUND: We report two cases in which severe skin disorders developed during sorafenib treatment in patients with renal cell carcinoma (RCC) who had previously received nivolumab. CASE REPORT: Case 1: A 50-year-old man with RCC received nivolumab as the fifth-line therapy followed by sorafenib as the sixth-line therapy. On day 15 of sorafenib administration, the patient was hospitalized with systemic erythema multiforme, acne-like skin rash, and hand-foot syndrome. Case 2: A 40-year-old man with RCC received nivolumab as the second-line therapy followed by sorafenib as the fifth-line treatment. On day 12 of sorafenib administration, the patient was hospitalized with an acne-like skin rash and hand-foot syndrome. The skin disorders in the two cases improved within 2-3 weeks after sorafenib discontinuation and the start of treatment with topical and oral steroids. CONCLUSION: When using sorafenib in patients previously treated with nivolumab, close attention should be paid to the onset of serious skin disorders.

Sorafenib exposure and its correlation with response and safety in advanced hepatocellular carcinoma: results from an observational retrospective study.

PURPOSE: Severe adverse events frequently occur in patients treated with sorafenib, whereas some patients have suboptimal response to sorafenib. We aimed to evaluate the association of sorafenib-induced toxicities and clinical outcomes with the pharmacokinetics of sorafenib in patients with hepatocellular carcinoma (HCC). METHODS: This was a retrospective, observational study in which 26 HCC patients who had been treated with sorafenib were enrolled between September 2010 and March 2015. The association between trough sorafenib concentration and occurrence of grade ≥ 3 toxicities was evaluated. In addition, we estimated the association of trough sorafenib concentration with overall survival (OS). RESULTS: The median sorafenib concentration was 2.91 µg/mL (range 0.74-8.8 µg/mL). Based on the receiver operating characteristic curve, the threshold value of the trough sorafenib concentration for predicting grade ≥ 3 toxicities and responder (complete response or partial response at best response, or stable disease for ≥ 3 months) was 3.45 µg/mL [area under the curve (AUC) 0.74, 95% confidence interval (CI) 0.54-0.93; p <0.05] and 1.40 µg/mL (AUC 0.97, 95% CI 0.97-1.00; p <0.05), respectively. OS of patients with sorafenib 1.40-3.45 µg/mL had a tendency to be longer than those of patients administered < 1.40 µg/mL and ≥ 3.45 µg/mL [median 17.8 months (1.40-3.45 µg/mL) vs. 5.3 months (< 1.40 µg/mL) and 9.5 months (≥ 3.45 µg/mL)]. CONCLUSIONS: From results of this study, we proposed that the target range of sorafenib may be a trough concentration of 1.40-3.45 µg/mL in patients with HCC.