BACKGROUND Fusions involving one of three tropomyosin receptor kinases (TRK) occur in diverse cancers in children and adults. We evaluated the efficacy and safety of larotrectinib, a highly selective TRK inhibitor, in adults and children who had tumors with these fusions. METHODS We enrolled patients with consecutively and prospectively identified TRK fusion–positive cancers, detected by molecular profiling as routinely performed at each site, into one of three protocols: a phase 1 study involving adults, a phase 1–2 study involving children, or a phase 2 study involving adolescents and adults. The primary end point for the combined analysis was the overall response rate according to independent review. Secondary end points included duration of response, progression-free survival, and safety. RESULTS A total of 55 patients, ranging in age from 4 months to 76 years, were enrolled and treated. Patients had 17 unique TRK fusion–positive tumor types. The overall response rate was 75% (95% confidence interval [CI], 61 to 85) according to independent review and 80% (95% CI, 67 to 90) according to investigator assessment. At 1 year, 71% of the responses were ongoing and 55% of the patients remained progression-free. The median duration of response and progression-free survival had not been reached. At a median follow-up of 9.4 months, 86% of the patients with a response (38 of 44 patients) were continuing treatment or had undergone surgery that was intended to be curative. Adverse events were predominantly of grade 1, and no adverse event of grade 3 or 4 that was considered by the investigators to be related to larotrectinib occurred in more than 5% of patients. No patient discontinued larotrectinib owing to drug-related adverse events. CONCLUSIONS Larotrectinib had marked and durable antitumor activity in patients with TRK fusion–positive cancer, regardless of the age of the patient or of the tumor type. (Funded by Loxo Oncology and others; ClinicalTrials.gov numbers, NCT02122913, NCT02637687, and NCT02576431.)

Lenvatinib, as compared with placebo, was associated with significant improvements in progression-free survival and the response rate among patients with iodine-131-refractory thyroid cancer. Patients who received lenvatinib had more adverse effects. (Funded by Eisai; SELECT ClinicalTrials.gov number, NCT01321554.).

Background Patients with radioactive iodine (131I, RAI)-refractory locally advanced or metastatic differentiated thyroid cancer (DTC) have a poor prognosis due to the lack of effective treatment options. Methods This multicentre, randomized (1:1), double-blind, placebo-controlled, phase 3 study (DECISION; NCT00984282) investigated sorafenib (400 mg orally twice-daily) in patients with RAI-refractory locally advanced or metastatic DTC progressing within the past 14 months. The primary endpoint was progression-free survival (PFS) by central independent review. Patients receiving placebo could crossover to open-label sorafenib upon progression. Archival tumour tissue was examined for BRAF and RAS mutations. Serum thyroglobulin was measured at baseline and each visit. Findings A total of 417 patients were randomized to sorafenib (n=207) or placebo (n=210). Sorafenib treatment significantly improved PFS compared with placebo (hazard ratio, 0·59; 95% confidence interval, 0·45–0·76; P<0·0001; median 10·8 vs. 5·8 months, respectively). PFS improvement was seen in all pre-specified clinical and genetic biomarker subgroups irrespective of mutation status. There was no statistically significant difference in overall survival (hazard ratio, 0·80; 95% confidence interval, 0·54–1·19; P=0·14); median overall survival had not been reached and 150 (71%) patients receiving placebo crossed over to sorafenib upon progression. Response rates (all partial responses) were 12·2% (24/196; sorafenib) and 0·5% (1/201; placebo; p<0·0001). Median thyroglobulin levels increased in the placebo group, and decreased, then paralleled treatment responses in the sorafenib group. Most adverse events were grade 1 or 2. The most common treatment-emergent adverse events in the sorafenib arm were hand–foot skin reaction (76·3%), diarrhoea (68·6%), alopecia (67·1%), and rash/desquamation (50·2%). Interpretation Sorafenib significantly improved PFS compared with placebo in patients with progressive RAI-refractory DTC. Adverse events were consistent with the known sorafenib safety profile. These results suggest that sorafenib represents a new treatment option for patients with progressive RAI-refractory DTC.

A B S T R A C T PurposeCabozantinib, a tyrosine kinase inhibitor (TKI) of hepatocyte growth factor receptor (MET), vascular endothelial growth factor receptor 2, and rearranged during transfection (RET), demonstrated clinical activity in patients with medullary thyroid cancer (MTC) in phase I. Patients and MethodsWe conducted a double-blind, phase III trial comparing cabozantinib with placebo in 330 patients with documented radiographic progression of metastatic MTC. Patients were randomly assigned (2:1) to cabozantinib (140 mg per day) or placebo. The primary end point was progression-free survival (PFS). Additional outcome measures included tumor response rate, overall survival, and safety. ResultsThe estimated median PFS was 11.2 months for cabozantinib versus 4.0 months for placebo (hazard ratio, 0.28; 95% CI, 0.19 to 0.40; P Ͻ .001). Prolonged PFS with cabozantinib was observed across all subgroups including by age, prior TKI treatment, and RET mutation status (hereditary or sporadic). Response rate was 28% for cabozantinib and 0% for placebo; responses were seen regardless of RET mutation status. Kaplan-Meier estimates of patients alive and progression-free at 1 year are 47.3% for cabozantinib and 7.2% for placebo. Common cabozantinibassociated adverse events included diarrhea, palmar-plantar erythrodysesthesia, decreased weight and appetite, nausea, and fatigue and resulted in dose reductions in 79% and holds in 65% of patients. Adverse events led to treatment discontinuation in 16% of cabozantinib-treated patients and in 8% of placebo-treated patients. ConclusionCabozantinib (140 mg per day) achieved a statistically significant improvement of PFS in patients with progressive metastatic MTC and represents an important new treatment option for patients with this rare disease. This dose of cabozantinib was associated with significant but manageable toxicity.