title: Phase I dose escalation and pharmacokinetic study of AZD2171, an inhibitor of the vascular endothelial growth factor receptor tyrosine kinase, in patients with hormone refractory prostate cancer (HRPC).
abstract: To explore the pharmacokinetics and tolerability of AZD2171, an inhibitor of vascular endothelial growth factor receptors 1 and 2, in patients with hormone refractory prostate cancer. Twenty-six patients received oral daily dosing of AZD2171 at 1, 2.5, 5, 10, 20, 30 mg. The maximum tolerated dose (MTD) was defined as the dose below that at which >or=33% of patients experienced a dose-limiting toxicity (DLT) within 21 days of initiating therapy. Pharmacokinetic analysis was performed. DLTs occurred at the 30 mg dose and included grade 3 events in three patients: fatigue (n = 3) and muscle weakness (n = 2). The pharmacokinetic profile revealed an effective half-life of approximately 27 h. At steady state, the unbound drug concentration was 4.4 times above the concentration required to inhibit endothelial cell proliferation in vitro. Four patients experienced PSA reductions within 30 days following drug discontinuation (one on 2.5 mg, two on 20 mg and 1 on 30 mg). In two patients treated with 20 mg, post therapy PSA declines persisted for >17 months, despite a PSA increase on therapy. Resolution of adenopathy occurred in one patient persisting for >17 months. Plasma concentrations were maximum 2-8 h post dosing with an overall median value of 2 h. The dose of 20 mg daily was declared as the MTD. One objective response and several PSA declines following the discontinuation of therapy for toxicity suggest that evidence of clinical efficacy may be delayed. While further study is indicated, careful attention must be paid to the novel toxicities of this agent with prolonged dosing.
authors: Urologic Oncology Program, UCSF Comprehensive Cancer Center, 1600 Divisadero-3rd Floor, San Francisco, CA, USA. ryanc@medicine.ucsf.edu
authors: Charles J
authors: CJ
authors: Ryan
authors: Walter M
authors: WM
authors: Stadler
authors: Bruce
authors: B
authors: Roth
authors: Douglass
authors: D
authors: Hutcheon
authors: Shauna
authors: S
authors: Conry
authors: Thomas
authors: T
authors: Puchalski
authors: Charles
authors: C
authors: Morris
authors: Eric J
authors: EJ
authors: Small
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011799:Quinazolines / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000037:antagonists & inhibitors; D007211:Indoles
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D017430:Prostate-Specific Antigen; D011505:Protein-Tyrosine Kinases; D011799:Quinazolines; D040281:Vascular Endothelial Growth Factor Receptor-1; C501162:FLT1 protein, human; C500926:cediranib; D007211:Indoles