Clinical and pharmacologic study of the farnesyltransferase inhibitor tipifarnib in cancer patients with normal or mildly or moderately impaired hepatic function

Purpose: This study explored the feasibility of treating patients with impaired hepatic function with tipifarnib. The safety profile, pharmacokinetics, and relationship between the pharmacokinetics and toxicities were evaluated. Patients and Methods: Patients with mildly or moderately impaired hepatic function (Child-Pugh classification) were treated with tipifarnib bid on days 1 to 5 of cycle 1. Further dosing was based on the individual day 5 pharmacokinetic data and absolute neutrophil count. For patients with normal hepatic function, tipifarnib was dosed on days 1 to 14, followed by 1 week of rest. For all patients, in subsequent cycles, tipifarnib was administered for 21 consecutive days out of every 28 days. Results: Twenty-eight patients were included in the normal (n = 16), mild (n = 9), and moderate (n = 3) impairment groups. The most important grade 3 to 4 hematologic toxicity was leukocytopenia/ neutropenia, which was mostly observed in patients with moderate impairment. Common nonhematologic toxicities were fatigue, nausea, and vomiting. The pharmacokinetic data showed higher plasma concentrations of tipifarnib in patients with liver impairment compared with patients with normal hepatic function. Conclusion: In patients with mildly impaired hepatic function, tipifarnib can be administered safely at a starting dose of 200 mg bid, but it is not safe to treat patients with moderate hepatic impairment

Effects of metformin and statins on outcomes in men with castration-resistant metastatic prostate cancer: Secondary analysis of COU-AA-301 and COU-AA-302

Background: The associations of metformin and statins with overall survival (OS) and prostate specific antigen response rate (PSA-RR) in trials in metastatic castration-resistant prostate cancer remain unclear. Objective: To determine whether metformin or statins ± abiraterone acetate plus prednisone/prednisolone (AAP) influence OS and PSA-RR. Design, setting and participant: COU-AA-301 and COU-AA-302 patients were stratified by metformin and statin use. Cox proportional hazards models were used to estimate hazards ratio (HR) stratified by concomitant medications, and a random effects model was used to pool HR. We compared PSA-RR using Chi χ2 test. Results: In COU-AA-301-AAP, metformin was associated with improved PSA-RR (41.1% versus 28.6%) but not prolonged OS. In COU-AA-301-placebo-P, there was no association between metformin and prolonged OS or PSA-RR. In COU-AA-302-AAP, metformin was associated with prolonged OS (adjHR 0.69, 95% CI 0.48–0.98) and improved PSA-RR (72.7% versus 60.0%). In COU-AA-302-P, metformin was associated with prolonged OS (adjHR 0.66, 95% CI 0.47–0.93). In pooled analysis, OS was prolonged among those treated with metformin (pooled HR 0.77, 95% CI 0.62–0.95).In COU-AA-301-AAP, statins were associated with an improved OS (adjHR 0.76, 95% CI 0.62–0.93), while there was no difference in COU-AA-301-P. There was no association with statins and OS in either COU-AA-302 groups. When pooling HR, OS was prolonged among those treated with statins (pooled HR 0.78, 95% CI 0.68–0.88). Conclusion: Within the limitations of post-hoc sub-analyses, metformin and statins are associated with a prolonged OS and increased PSA-RR, particularly in combination with AAP

Modernizing clinical trial eligibility criteria: Recommendations of the ASCO-Friends of Cancer Research Prior Therapies Work Group

PURPOSE: Restrictive eligibility criteria induce differences between clinical trial and real-world treatment populations. Restrictions based on prior therapies are common; minimizing them when appropriate may increase patient participation in clinical trials. EXPERIMENTAL DESIGN: A multi-stakeholder working group developed a conceptual framework to guide evaluation of prevailing practices with respect to using prior treatment as selection criteria for clinical trials. The working group made recommendations to minimize restrictions based on prior therapies within the boundaries of scientific validity, patient centeredness, distributive justice, and beneficence. RECOMMENDATIONS: (i) Patients are eligible for clinical trials regardless of the number or type of prior therapies and without requiring a specific therapy prior to enrollment unless a scientific or clinically based rationale is provided as justification. (ii) Prior therapy (either limits on number and type of prior therapies or requirements for specific therapies before enrollment) could be used to determine eligibility in the following cases: a) the agents being studied target a specific mechanism or pathway that could potentially interact with a prior therapy; b) the study design requires that all patients begin protocol-specified treatment at the same point in the disease trajectory; and c) in randomized clinical studies, if the therapy in the control arm is not appropriate for the patient due to previous therapies received. (iii) Trial designers should consider conducting evaluation separately from the primary endpoint analysis for participants who have received prior therapies. CONCLUSIONS: Clinical trial sponsors and regulators should thoughtfully reexamine the use of prior therapy exposure as selection criteria to maximize clinical trial participation

A 2-gene classifier for predicting response to the farnesyltransferase inhibitor tipifarnib in acute myeloid leukemia

At present, there is no method available to predict response to farnesyltrans- ferase inhibitors (FTIs). We analyzed gene expression profiles from the bone marrow of patients from a phase 2 study of the FTI tipifarnib in older adults with previously untreated acute myeloid leukemia (AML). The RASGRP1/APTX gene expression ratio was found to predict response to tipifarnib with the greatest accuracy using a "leave one out" cross validation (LOOCV; 96%). RASGRP1 is a guanine nucleotide exchange factor that activates RAS, while APTX (aprataxin) is involved in DNA excision repair. The utility of this classifier for predicting response to tipifarnib was validated in an independent set of 58 samples from relapsed or refractory AML, with a negative predictive value (NPV) and positive predictive value (PPV) of 92% and 28%, respectively (odds ratio of 4.4). The classifier also predicted for improved overall survival (154 vs 56 days; P < .001), which was independent of other covariates, including a previously described prognostic gene expression classifier. Therefore, these data indicate that a 2-gene expression assay may have utility in categorizing a population of patients with AML who are more likely to respond to tipifarnib