The combination of paclitaxel, carboplatin and cetuximab (PCC) is efficacious in patients with recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN). The current study assessed the incidence of grade 3/4 (G3/4) toxicity for patients receiving weekly or 3-weekly PCC for R/M SCCHN. The present single-institution, retrospective analysis included 74 patients who received weekly [paclitaxel 45 mg/m(2) and carboplatin area under the curve (AUC), 1.5] or 3-weekly (paclitaxel 175 mg/m(2) and carboplatin AUC, 5) PCC. For each regimen, cetuximab was administered at 400 mg/m(2) for the first week, after which the dosage was reduced to 250 mg/m(2) weekly until disease progression occurred. Toxicity was assessed according to the Common Terminology Criteria for Adverse Events v4.03, and response to therapy was determined using computed tomography every 12 weeks. The results revealed that 26 patients (35%) received weekly PCC and 48 patients (65%) received PCC every 3 weeks. A total of 6 (25%) patients receiving weekly PCC experienced G3/4 toxicity compared with 30 (66%) patients that received PCC every 3 weeks (odds ratio, 0.18; 95% confidence interval, 0.05-0.64; P=0.01). The most common G3/4 side effects were neutropenia (8 vs. 53%), anemia (15 vs. 32%) and fatigue (3 vs. 10%). The incidence of G3/4 toxicity or any grade toxicity requiring dose modification or discontinuation was 74 vs. 77%, respectively. The overall response rate was 39% with weekly PCC compared with 27% in those receiving PCC every 3 weeks. The 1-year progression-free and overall survival rates were 27 and 46% for patients receiving weekly PCC, and 13 and 44% for patients receiving PCC every 3 weeks. Weekly PCC had a reduced risk of G3/4 toxicity when compared with PCC administered every 3 weeks. Considering the improved tolerance of weekly PCC, this regimen should be considered for older patients and patients being treated with second-line chemotherapy.

Tenosynovial giant cell tumor (TGCT) is a rare benign tumor that involves the synovium, bursa, and tendon sheath, resulting in reduced mobility of the affected joint or limb. The current standard of care for TGCT is surgical resection. However, some patients have tumor recurrence, present with unresectable tumors, or have tumors that are in locations where resection could result in amputations or significant debility. Therefore, the development of systemic agents with activity against TGCT to expand treatment options is a highly unmet medical need. Pathologically, TGCT is characterized by the overexpression of colonystimulating factor 1 (CSF-1), which leads to the recruitment of colony-stimulating factor-1 receptor (CSF-1R) expressing macrophages that make up the primary cell type within these giant cell tumors. The binding of CSF-1 and CSF-1R controls cell survival and proliferation of monocytes and the switch from a monocytic to macrophage phenotype contributing to the growth and inflammation within these tumors. Therefore, molecules that target CSF-1/CSF-1R have emerged as potential systemic agents for the treatment of TGCT. Given the role of macrophages in regulating tumorigenesis, CSF1/CSF-1R-targeting agents have emerged as attractive therapeutic targets for solid tumors. Pexidartinib is an orally bioavailable and potent inhibitor of CSF-1R which is one of the most clinically used agents. In this review, we discuss the biology of TGCT and review the pre-clinical and clinical development of pexidartinib which ultimately led to the FDA approval of this agent for the treatment of TGCT as well as ongoing clinical studies utilizing pexidartinib in the setting of cancer.

Methotrexate is a dihydrofolate reductase inhibitor that interferes with DNA synthesis, DNA repair, and cellular replication. We present the first adult case of a patient who received intravenous contrast prior to administration of high-dose methotrexate, who subsequently experienced delayed methotrexate clearance and renal impairment necessitating the use of glucarpidase. This case displays a possible correlation between intravenous radiographic contrast administration and resulting toxicity due to delayed methotrexate clearance.