In:
Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 18, No. 2 ( 2012-01-15), p. 568-576
Abstract:
Purpose: To identify the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of the first-in-class, oral CDK4/6 inhibitor PD 0332991 administered once daily for 21 of 28 days (3/1 schedule) in patients with retinoblastoma protein (Rb)-positive advanced solid tumors and to describe pharmacokinetic–pharmacodynamic relationships relative to drug effects. Experimental Design: This open-label phase I study (NCT00141297) enrolled patients who received PD 0332991 orally in six dose-escalation cohorts in a standard 3 + 3 design. Results: Forty-one patients were enrolled. DLTs were observed in five patients (12%) overall; at the 75, 125, and 150 mg once daily dose levels. The MTD and recommended phase II dose of PD 0332991 was 125 mg once daily. Neutropenia was the only dose-limiting effect. After cycle 1, grade 3 neutropenia, anemia, and leukopenia occurred in five (12%), three (7%), and one (2%) patient(s), respectively. The most common non-hematologic adverse events included fatigue, nausea, and diarrhea. Thirty-seven patients were evaluable for tumor response; 10 (27%) had stable disease for ≥4 cycles of whom six derived prolonged benefit (≥10 cycles). PD 0332991 was slowly absorbed (median Tmax, 5.5 hours), and slowly eliminated (mean half-life was 25.9 hours) with a large volume of distribution (mean, 2,793 L). The area under the concentration–time curve increased linearly with dose. Using an Emax model, neutropenia was shown to be proportional to exposure. Conclusions: PD 0332991 warrants phase II testing at 125 mg once daily, at which dose neutropenia was the sole significant toxicity. Clin Cancer Res; 18(2); 568–76. ©2011 AACR.
Type of Medium:
Online Resource
ISSN:
1078-0432
,
1557-3265
DOI:
10.1158/1078-0432.CCR-11-0509
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2012
detail.hit.zdb_id:
1225457-5
detail.hit.zdb_id:
2036787-9
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