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Vemurafenib is a BRAF kinase inhibitor indicated for the treatment of patients with BRAFV600mutation–positive unresectable or metastatic melanoma and Erdheim‐Chester disease. This phase 1, open‐label, single‐arm study was designed to estimate absolute bioavailability of oral vemurafenib at steady state and to characterize the pharmacokinetics of a single intravenous microdose of 14C‐labeled vemurafenib in patients with BRAFV600mutation–positive malignancies. Patients received oral vemurafenib 960 mg twice daily on days 1 through 28, with a single intravenous infusion of 14C‐labeled vemurafenib solution (3 mL, corresponding to a radioactive dose of 18.5 kBq and a vemurafenib dose of 20 µg) given on the morning of day 21, immediately following the morning dose of oral vemurafenib. A total of 6 patients were enrolled. Four patients who received 14C‐labeled vemurafenib infusion were included in the pharmacokinetic and bioavailability analyses. Geometric mean absolute bioavailability of oral vemurafenib at steady state, calculated as the ratio of dose‐normalized area under the curve during the dosing interval (AUCτ) following oral vemurafenib dose to dose‐normalized AUC from time 0 extrapolated to infinity (AUC0‐inf) following vemurafenib intravenous dose, was 57.8%. The majority of radioactivity (geometric mean 41%) was recovered in feces, and a small proportion (geometric mean 1.4%) was recovered in urine. Treatment‐emergent adverse events occurred in 5 of 6 (83%) patients and were all grade 1/2 in severity, except for 1 grade‐4 anaphylactic reaction occurring during infusion of 14C‐labeled vemurafenib, which was thought to be related to the excipient polysorbate 80 in the intravenous formulation.

IMPORTANCE: Standard therapy for advanced soft-tissue sarcoma has not changed substantially in decades, and patient prognosis remains poor. Aldoxorubicin, a novel albumin-binding prodrug of doxorubicin, showed clinical activity against advanced soft-tissue sarcoma in phase 1 studies. OBJECTIVE: To evaluate efficacy and safety of aldoxorubicin vs doxorubicin in patients with advanced soft-tissue sarcoma. DESIGN, SETTING, AND PARTICIPANTS: International, multicenter, phase 2b, open-label, randomized study at general community practices, private practices, or institutional practices. Between August 2012 and December 2013, 140 patients with previously untreated locally advanced, unresectable, or metastatic soft-tissue sarcoma were screened. INTERVENTIONS: Randomization (2:1) to aldoxorubicin 350 mg/m2 (dose equivalent to doxorubicin 260 mg/m2) or doxorubicin 75 mg/m2, administered once every 3 weeks for up to 6 cycles. MAIN OUTCOMES AND MEASURES: Primary end point was progression-free survival. Secondary end points were 6-month progression-free survival, overall survival, tumor response rate, and safety. All efficacy end points were evaluated by independent and local review. RESULTS: A total of 126 patients were randomized, and 123 received aldoxorubicin (n = 83) or doxorubicin (n = 40). Median (range) patient age was 54.0 (21-77 years); 42 (34%) had leiomyosarcoma. By independent review, median progression-free survival was significantly improved (5.6 [95% CI, 3.0-8.1] vs 2.7 [95% CI, 1.6-4.3] months; P = .02) with aldoxorubicin compared with doxorubicin, as was the rate of 6-month progression-free survival (46% and 23%; P = .02). Median overall survival was 15.8 (95% CI, 13.0 to not available) months with aldoxorubicin and 14.3 (95% CI, 8.6-20.6) months with doxorubicin (P = .21). Overall tumor response rate (by Response Evaluation Criteria in Solid Tumors, version 1.1) by independent review was higher with aldoxorubicin than with doxorubicin (25% [20 patients, all partial response] vs 0%). Grade 3 or 4 neutropenia was more frequent with aldoxorubicin than with doxorubicin (24 [29%] vs 5 [12%]), but not grade 3 or 4 febrile neutropenia (12 [14%] vs 7 [18%]). No acute cardiotoxic effects were observed with either treatment, although left ventricular ejection fraction less than 50% occurred in 3 of 40 patients receiving doxorubicin. CONCLUSIONS AND RELEVANCE: Single-agent aldoxorubicin therapy showed superior efficacy over doxorubicin by prolonging progression-free survival and improving rates of 6-month progression-free survival and tumor response. Aldoxorubicin therapy exhibited manageable adverse effects, without unexpected events, and without evidence of acute cardiotoxicity. Further investigation of aldoxorubicin therapy in advanced soft-tissue sarcoma is warranted. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01514188