RT Journal Article SR Electronic T1 Mapatumumab, a Fully Human Agonistic Monoclonal Antibody That Targets TRAIL-R1, in Combination with Gemcitabine and Cisplatin: a Phase I Study JF Clinical Cancer Research JO Clin Cancer Res FD American Association for Cancer Research SP 5584 OP 5590 DO 10.1158/1078-0432.CCR-09-0996 VO 15 IS 17 A1 Mom, Constantijne H. A1 Verweij, Jaap A1 Oldenhuis, Corina N.A.M. A1 Gietema, Jourik A. A1 Fox, Norma Lynn A1 Miceli, Renée A1 Eskens, Ferry A.L.M. A1 Loos, Walter J. A1 de Vries, Elisabeth G.E. A1 Sleijfer, Stefan YR 2009 UL http://clincancerres.aacrjournals.org/content/15/17/5584.abstract AB Purpose: To evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of mapatumumab, a fully human monoclonal antibody targeting tumor necrosis factor–related apoptosis–inducing ligand receptor 1 (TRAIL-R1), in combination with gemcitabine and cisplatin. Experimental Design: Patients with advanced solid tumors received gemcitabine 1,250 mg/m2 i.v. on days 1 and 8 and cisplatin 80 mg/m2 i.v. on day 1 of each 21-day cycle. Escalating mapatumumab doses were administered i.v. every 21 days. Toxicity was evaluated and pharmacokinetic analysis of plasma mapatumumab, gemcitabine, 2-difluoro-2-deoxyuridine, and unbound and total platinum was done. TRAIL-R1 tumor expression was determined immunohistochemically. Results: Forty-nine patients received mapatumumab (1 mg/kg, n = 4; 3 mg/kg, n = 7; 10 mg/kg, n = 12; 20 mg/kg, n = 13; or 30 mg/kg, n = 13). A median of six cycles (range, 1-48) was administered. The adverse events most commonly observed reflect the toxicity profile of gemcitabine and cisplatin. Dose-limiting toxicities were seen in 3 of 12 patients at 10 mg/kg, consisting of grade 3 transaminitis, neutropenic fever, and grade 4 thrombocytopenia. At 20 mg/kg, 2 of 12 patients had dose-limiting toxicities, including grade 4 thrombocytopenia and grade 4 fatigue. The maximum tolerated dose was not reached. Pharmacokinetic interactions have not been observed. Twelve patients had a partial response, and 25 patients showed stable disease with a median duration of 6 months. Conclusions: Mapatumumab in combination with gemcitabine and cisplatin is safe and well tolerated at doses up to 30 mg/kg. Further studies on this combination are warranted. (Clin Cancer Res 2009;15(17):5584–90)