title: Phase I and pharmacokinetic study of the novel platinum analogue CI-973 on a 5-daily dose schedule.
abstract: CI-973, a platinum(II) derivative with a 2-methyl-1,4-butanediamine carrier ligand, has activity in cisplatin-resistant tumor models in vitro and in vivo. In a Phase I pharmacokinetic study, 31 patients were treated with CI-973 (24 to 50 mg/m2/day for 5 days; 28-day cycles) given i.v. over 30 min without routine antiemetic prophylaxis or hydration. Of the 29 patients evaluable for maximum tolerated dose determination, most had a performance status of 0 or 1, and most had received prior chemotherapy. Neutropenia was dose limiting at 40 and 50 mg/m2/day. Recovery from neutropenia was generally rapid with nadir counts and recovery usually occurring by Days 15 and 22, respectively. Drug-associated thrombocytopenia was uncommon and never severe, even in patients with Grade 4 neutropenia. Anemia was common, but did not appear dose related. Drug-related nausea and vomiting and changes in renal function were relatively infrequent and mild. No clinically evident ototoxicity was reported, although changes in audiograms were noted in several patients. CI-973 concentrations were measured in plasma ultrafiltrate and urine by high-pressure liquid chromatography. The harmonic mean terminal half-life was 2.0 h. The mean CI-973 renal and nonrenal clearance values were 42.3 and 37.4 ml/min/m2, respectively. The mean recovery of CI-973 in urine was 53% of the administered dose. The mean ratio of CI-973 renal clearance to creatinine clearance was 0.92. Total clearance correlated with creatinine clearance (r2 = 0.63). A relationship between toxicity, expressed as the percentage of reduction in absolute granulocyte count, and area under the CI-973 plasma concentration-time curve was found in a subgroup of "good-risk" patients. This relationship, described well by a sigmoidal Emax pharmacodynamic model, did not hold for patients with extensive prior therapy or poor performance status. A model for toxicity prediction based on dose and creatinine clearance has been derived and will be validated in future studies. The recommended Phase II dose of CI-973 is 30 mg/m2/day for 5 days.
authors.affiliation: Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111.
authors.forename: P J
authors.initials: PJ
authors.lastname: O'Dwyer
authors.forename: G R
authors.initials: GR
authors.lastname: Hudes
authors.forename: J
authors.initials: J
authors.lastname: Walczak
authors.forename: R
authors.initials: R
authors.lastname: Schilder
authors.forename: F
authors.initials: F
authors.lastname: LaCreta
authors.forename: B
authors.initials: B
authors.lastname: Rogers
authors.forename: I
authors.initials: I
authors.lastname: Cohen
authors.forename: C
authors.initials: C
authors.lastname: Kowal
authors.forename: L
authors.initials: L
authors.lastname: Whitfield
authors.forename: R A
authors.initials: RA
authors.lastname: Boyd
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics*; D016190:Carboplatin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents; C055425:NK 121; D016190:Carboplatin