Weekly vs. 3-weekly paclitaxel, carboplatin, and cetuximab (PCC) in recurrent/metastatic head and neck cancer.

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/m2 and carboplatin area under the curve (AUC), 1.5] or 3-weekly (paclitaxel 175 mg/m2 and carboplatin AUC, 5) PCC. For each regimen, cetuximab was administered at 400 mg/m2 for the first week, after which the dosage was reduced to 250 mg/m2 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.

Effect of Acid-Suppressive Strategies on Pazopanib Efficacy in Patients With Soft-Tissue Sarcoma.

Pazopanib (PAZ), a tyrosine kinase inhibitor used in the treatment of soft tissue sarcoma (STS), should not be administered with acid-suppressive medications (ASMs) due to decreased drug solubility. Common practice for patients requiring ASM with PAZ is to separate administration by 12 hours; however, there is little real-world evidence describing clinical outcomes using this strategy. The aim of this study was to determine whether concomitant ASM impacted efficacy and adverse event rates in patients with STS receiving PAZ. Medical records were retrospectively reviewed for patients with STS who received PAZ from June 2011 to July 2017. Patients were stratified into two groups, PAZ with or without ASM (PAZ + ASM or PAZ only). The primary objective was to determine whether progression-free survival (PFS) differed between groups. Secondary objectives were to determine overall survival (OS) and occurrence of grade 3/4 toxicities. Ninety-one patients were included in the study, 42 patients in the PAZ + ASM group and 49 in the PAZ only group. Median PFS was significantly shorter in the PAZ + ASM group than the PAZ only group (5.3 vs. 6.7 months). The PAZ + ASM group also had a 74% higher relative risk of progression or death than the PAZ only group, but there was no difference in OS. Regarding adverse events, the PAZ + ASM group trended toward lower levels of grade 3/4 hypertension (19% vs. 37%). These results suggest that ASM should be avoided in patients with STS receiving PAZ. Larger studies are needed to further elucidate the impact of ASM use with PAZ in clinical practice.

Detection of genes regulated by Lmx1b during limb dorsalization.

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes that were differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism that includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation.