A Grant-Based Experiment to Train Clinical Investigators: The AACR/ASCO Methods in Clinical Cancer Research Workshop.

To address the need for clinical investigators in oncology, American Association for Cancer Research (AACR) and American Society for Clinical Oncology (ASCO) established the Methods in Clinical Cancer Research Workshop (MCCRW). The workshop's objectives were to: (i) provide training in the methods, design, and conduct of clinical trials; (ii) ensure that clinical trials met federal and international ethical guidelines; (iii) evaluate the effectiveness of the workshop; and (iv) create networking opportunities for young investigators with mentoring senior faculty. Educational methods included: (i) didactic lectures, (ii) Small Group Discussion Sessions, (iii) Protocol Development Groups, and (iv) one-on-one mentoring. Learning focused on the development of an Institutional Review Board (IRB)-ready protocol, which was submitted on the last day of the workshop. Evaluation methods included: (i) pre- and postworkshop tests, (ii) students' workshop evaluations, (iii) faculty's ratings of protocol development, (iv) students' productivity in clinical research after the workshop, and (v) an independent assessment of the workshop. From 1996 to 2014, 1,932 students from diverse backgrounds attended the workshop. There was a significant improvement in the students' level of knowledge from the pre- to the postworkshop exams (P < 0.001). Across the classes, student evaluations were very favorable. At the end of the workshop, faculty rated 92% to 100% of the students' protocols as ready for IRB submission. Intermediate and long-term follow-ups indicated that more than 92% of students were actively involved in patient-related research, and 66% had implemented five or more protocols. This NCI-sponsored MCCRW has had a major impact on the training of clinicians in their ability to design and implement clinical trials in cancer research.

Assessment of effects of repeated oral doses of fedratinib on inhibition of cytochrome P450 activities in patients with solid tumors using a cocktail approach.

PURPOSE: Fedratinib, an oral selective kinase inhibitor with activity against both wild type and mutationally activated Janus kinase 2, has been approved for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis by the US Food and Drug Administration. In vitro studies indicated that fedratinib was an inhibitor of several cytochrome P450 (CYP) enzymes. The primary objective of this study was to evaluate the effects of repeated doses of fedratinib on the activity of CYP2D6, CYP2C19, and CYP3A4 in patients with solid tumors using a CYP probe cocktail. METHODS: An open-label, one-sequence, two-period, two-treatment crossover study was conducted. Patients were administered a single oral dose cocktail of metoprolol (100 mg), omeprazole (20 mg), and midazolam (2 mg) used as probe substrates for CYP2D6, CYP2C19, and CYP3A4 enzyme activities, respectively, without fedratinib on Day -1 or with fedratinib on Day 15. RESULTS: Coadministration of 500 mg once-daily doses of fedratinib for 15 days increased the mean area under the plasma concentration-time curve from time zero to infinity following a single-dose cocktail containing metoprolol (CYP2D6 substrate), omeprazole (CYP2C19 substrate), and midazolam (CYP3A4 substrate) by 1.77-fold (90% confidence interval [CI] 1.27-2.47) for metoprolol, 2.82-fold (90% CI 2.26-3.53) for omeprazole, and 3.84-fold (90% CI 2.62-5.63) for midazolam, respectively. The mean plasma Day 14/Day 1 ratio of 4ß-hydroxycholesterol, an endogenous biomarker of CYP3A4 activity, was 0.59 (90% CI 0.54-0.66), suggesting a net inhibition of CYP3A4 by fedratinib. CONCLUSION: Fedratinib is a weak inhibitor of CYP2D6, and a moderate inhibitor of CYP2C19 and CYP3A4. These results serve as the basis for dose modifications of these CYP substrate drugs when co-administered with fedratinib.

Assessment of the drug interaction potential and single- and repeat-dose pharmacokinetics of the BRAF inhibitor dabrafenib.

The induction of CYP2C9 by dabrafenib using S-warfarin as a probe and the effects of a CYP3A inhibitor (ketoconazole) and a CYP2C8 inhibitor (gemfibrozil) on dabrafenib pharmacokinetics were evaluated in patients with BRAF V600 mutation-positive tumors. Dabrafenib single- and repeat-dose pharmacokinetics were also evaluated. S-warfarin AUC(0- ∞) decreased 37% and Cmax increased 18% with dabrafenib. Dabrafenib AUC(0- τ) and C(max) increased 71% and 33%, respectively, with ketoconazole. Hydroxy- and desmethyl-dabrafenib AUC(0-τ) increased 82% and 68%, respectively, and AUC for carboxy-dabrafenib decreased 16%. Dabrafenib AUC(0-τ) increased 47%, with no change in C(max), after gemfibrozil co-administration. Gemfibrozil did not affect systemic exposure to dabrafenib metabolites. Single- and repeat-dose dabrafenib pharmacokinetics were consistent with previous reports. All cohorts used the commercial capsules. More-frequent monitoring of international normalized ratios is recommended in patients receiving warfarin during initiation or discontinuation of dabrafenib. Substitution of strong inhibitors or strong inducers of CYP3A or CYP2C8 is recommended during treatment with dabrafenib.

Co-administration of vismodegib with rosiglitazone or combined oral contraceptive in patients with locally advanced or metastatic solid tumors: a pharmacokinetic assessment of drug-drug interaction potential.

PURPOSE: Vismodegib, a first-in-class oral hedgehog pathway inhibitor, is an effective treatment for advanced basal cell carcinoma. Based on in vitro data, a clinical drug-drug interaction (DDI) assessment of cytochrome P450 (CYP) 2C8 was necessary; vismodegib's teratogenic potential warranted a DDI study with oral contraceptives (OCs). METHODS: This single-arm, open-label study included two cohorts of patients with locally advanced or metastatic solid malignancies [Cohort 1: rosiglitazone 4 mg (selective CYP2C8 probe); Cohort 2: OC (norethindrone 1 mg/ethinyl estradiol 35 µg; CYP3A4 substrate)]. On Day 1, patients received rosiglitazone or OC. On Days 2-7, patients received vismodegib 150 mg/day. On Day 8, patients received vismodegib plus rosiglitazone or OC. The effect of vismodegib on rosiglitazone and OC pharmacokinetic parameters (primary objective) was evaluated through pharmacokinetic sampling over a 24-h period (Days 1 and 8). RESULTS: The mean ± SD vismodegib steady-state plasma concentration (Day 8, N = 51) was 20.6 ± 9.72 µM (range 7.93-62.4 µM). Rosiglitazone AUC(0-inf) and C(max) were similar with concomitant vismodegib [≤8% change in geometric mean ratios (GMRs); N = 24]. Concomitant vismodegib with OC did not affect ethinyl estradiol AUC(0-inf) and C(max) (≤5% change in GMRs; N = 27); norethindrone C(max) and AUC(0-inf) GMRs were higher (12 and 23%, respectively) with concomitant vismodegib. CONCLUSIONS: This DDI study in patients with cancer demonstrated that systemic exposure of rosiglitazone (a CYP2C8 substrate) or OC (ethinyl estradiol/norethindrone) is not altered with concomitant vismodegib. Overall, there appears to be a low potential for DDIs when vismodegib is co-administered with other medications.

Making the investigational oncology pipeline more efficient and effective: are we headed in the right direction?

Advances in our knowledge of the molecular mechanisms involved in cancer biology have contributed to an increase in novel target-specific oncology therapeutics. Unfortunately, clinical development of new drugs is an expensive and slow process, and the patient and financial resources needed to study the vast number of potential therapies are limited, requiring novel approaches to clinical trial design and patient recruitment. In addition, traditional efficacy endpoints may not be adequate to fully determine the therapeutic worth of the new classes of targeted agents. In this new era of drug development, it has become increasingly clear that new clinical trial design paradigms that examine nontraditional endpoints have become necessary to assist in prioritizing the development of the most promising agents. It is also vital that individual patient management be considered, and the subpopulations of patients most likely to derive benefit or experience harm from a new therapy be identified as early as possible. Phase I and II clinical trials allow investigators doing clinical research the opportunity to define these critical endpoints and subpopulations early on, before conducting large-scale randomized phase III clinical trials, which require an abundance of financial and patient resources.