R115777 is bioavailable after oral administration and has an acceptable toxicity profile. Based upon pharmacokinetic data, the recommended dose for phase II trials is 500 mg orally bid (total daily dose, 1, 000 mg) for 5 consecutive days followed by 9 days of rest. Studies of continuous dosing and studies of R115777 in combination with chemotherapy are ongoing.

Continuous dosing of R115777 is feasible with an acceptable toxicity profile at a dose of 300 mg bid.

R115777 is a novel selective inhibitor of farnesyl transferase, an enzyme that is involved in the proliferation of the malignant cell type. This study was designed to determine the toxicity, maximal tolerated dose and pharmacokinetics of R115777 when given orally b.i.d. for 28 days followed by 1-2 weeks of rest. Patients with advanced solid tumors for whom no standard therapy was available could enter the study. The starting dose of R115777 was 200 mg/dose and inter- as well as intra-patient dose escalations were performed with increments of 100 mg/dose. Nine patients entered the study and received in total 23 treatment cycles. A dose of 300 mg b.i.d. proved feasible with grade 4 neutropenia occurring in one of six patients who completed the first treatment cycle. Other toxicities were infrequent. Pharmacokinetic analysis demonstrated that peak plasma concentrations of 881+/-393 ng/ml were reached within 1-5 h. No accumulation of R115777 was observed over a 28-day period. The study was terminated based on these results together with the observation from a related phase I study in which higher doses of R115777 were associated with the frequent occurrence of grade 3-4 myelosuppression. We conclude that the recommended dose of R115777 given for 28 days followed by 1-2 weeks of rest is 300 mg b.i.d. Myelosuppression is the dose-limiting toxicity.

No abstract

No abstract

This study confirms that the XIENCE Vstent causes a limited and systemic exposure to everolimus. The presumed localized and efficient delivery of everolimus to target vessels coupled with limited and transient systemic drug exposure contributes to the safety and effectiveness of the XIENCE VEECSS in patients of SPIRIT III RCT for longer than 2 years.

R115777 (Zamestra) is a novel anticancer agent, currently undergoing phase III clinical testing. An open, cross-over trial was performed in 24 patients with solid tumors to compare the bioavailability of a new tablet formulation with the standard capsule formulation. Both dosage forms were administered once daily in doses of 300 or 400 mg. Patients received R115777 as a capsule on day I and as a tablet on day 2, or vice versa. Blood samples were drawn up to 24 hours after drug intake and R115777 levels were measured using a validated high performance liquid chromatography (HPLC) method. The following pharmacokinetic parameters were determined and compared for the two formulations: time to maximal plasma concentration (Tmax), half-life (t 1/2), maximal plasma concentration (Cmax) and area under the curve at twenty-four hours (AUC24h). For the latter two parameters, 90% classical confidence intervals of the ratio tablet/capsule were calculated after a log-transformation, using an Analysis of Variance (ANOVA). For t 1/2 and Tmax, no statistically significant differences were found between tablet and capsule. The point estimates of the ratio's of the log-normalized Cmax and AUC24h were 0.94 and 0.92, respectively, and the 90% confidence intervals were 0.81-1.09 and 0.83-1.03, which is within the critical range for bioequivalence of 0.80-1.25. In conclusion, the established pharmacokinetic parameters demonstrate that the capsule and tablet formulations of R115777 are interchangeable.

No abstract