An index for evaluating difficulty of Chewing Index for chewable tablets.

Chewing difficulty index, a potential measure of difficulty in chewing the chewable tablets, has been described herein as the product of tablet thickness and tablet hardness measured under the diametral loading. The proposed index was evaluated by measuring the dimensions and mechanical strength of commercial and in-house prepared chewable tablets. Data collected on tablets with different thickness but same hardness or tensile strength suggests that the proposed index provides a good assessment of the force needed to chew the chewable tablets. Influence of brief exposure to salivary fluid during chewing on the mechanical strength of the chewable tablets was also evaluated. Thirty seconds exposure to the simulated salivary fluid was also found to significantly reduce (p < 0.05) the hardness and the chewing difficulty index of a number of evaluated chewable tablet drug products.

Approval summary: sunitinib for the treatment of imatinib refractory or intolerant gastrointestinal stromal tumors and advanced renal cell carcinoma.

PURPOSE: To describe the Food and Drug Administration (FDA) review and approval of sunitinib malate (Sutent). Sunitinib received regular approval for the treatment of gastrointestinal stromal tumor (GIST) after disease progression or intolerance to imatinib mesylate (Gleevec). Additionally, sunitinib received accelerated approval for the treatment of advanced renal cell carcinoma. EXPERIMENTAL DESIGN: For the GIST indication, FDA reviewed data from a randomized, placebo-controlled trial with supportive evidence from a single-arm study. For the advanced renal cell carcinoma indication, FDA reviewed data from two single-arm studies of patients with cytokine-refractory metastatic renal cell carcinoma. RESULTS: In patients with imatinib refractory or intolerant GIST, time-to-tumor progression of sunitinib-treated patients was superior to that of placebo-treated patients. Median time-to-tumor progression of sunitinib-treated patients was 27.3 weeks, compared with 6.4 weeks for placebo-treated patients (P < 0.0001). Partial responses were observed in 6.8% of sunitinib-treated patients. In patients with metastatic renal cell carcinoma, partial responses were observed in 25.5% (95% confidence interval, 17.5, 34.9) and 36.5% (95% confidence interval, 24.7, 49.6) of patients treated with sunitinib. Median response durations were 27.1 and 54 weeks. The most common adverse events attributed to sunitinib included diarrhea, mucositis, skin abnormalities, and altered taste. Reductions in left ventricular ejection fraction and severe hypertension were also more common in sunitinib-treated patients. CONCLUSIONS: On January 26, 2006, the FDA approved sunitinib for the treatment of patients with imatinib refractory or intolerant GIST. Accelerated approval was granted for the treatment of advanced renal cell carcinoma.

PQRI recommendations on particle-size analysis of drug substances used in oral dosage forms.

This document provides information for the Pharmaceutical Industry and the Federal Drug Administration (FDA) regarding the selection of suitable particle-size analysis techniques, development and validation of particle-size methods, and the establishment of acceptance criteria for the particle size of drug substances used in oral solid-dosage forms. The document is intended for analysts knowledgeable in the techniques necessary to conduct particle-size characterization (a table of acronyms is provided at the end of the document). It is acknowledged that each drug substance, formulation, and manufacturing process is unique and that multiple techniques and instruments are available to the analyst.

Sorafenib for the treatment of advanced renal cell carcinoma.

PURPOSE: This report describes the U.S. Food and Drug Administration (FDA) review and approval of sorafenib (Nexavar, BAY43-9006), a new small-molecule, oral, multi-kinase inhibitor for the treatment of patients with advanced renal cell carcinoma (RCC). EXPERIMENTAL DESIGN: After meeting with sponsors during development studies of sorafenib, the FDA reviewed the phase 3 protocol under the Special Protocol Assessment mechanism. Following new drug application submission, FDA independently analyzed the results of two studies in advanced RCC: a large, randomized, double-blinded, phase 3 international trial of single-agent sorafenib and a supportive phase 2 study. RESULTS: In the phase 3 trial, 902 patients with advanced progressive RCC after one prior systemic therapy were randomized to 400 mg sorafenib twice daily plus best supportive care or to a matching placebo plus best supportive care. Primary study end points included overall survival and progression-free survival (PFS). A PFS analysis, pre-specified and conducted after a total of 342 events, showed statistically significant superiority for the sorafenib group (median = 167 days) compared with that for the controls (median = 84 days, log-rank P < 0.000001); the sorafenib/placebo hazard ratio was 0.44 (95% confidence interval, 0.35-0.55). Results were similar regardless of patient risk score, performance status, age, or prior therapy. The (partial) response rate to sorafenib was 2.1%. Overall survival results are preliminary. The principal toxicities in the sorafenib patients included reversible skin rashes in 40% and hand-foot skin reaction in 30%; diarrhea was reported in 43%, treatment-emergent hypertension was reported in 17%, and sensory neuropathic changes were reported in 13%. Grade 4 adverse events were uncommon. Grade 3 adverse events were hand-foot skin reaction (6%), fatigue (5%), and hypertension (3%). Laboratory findings included asymptomatic hypophosphatemia in 45% of sorafenib patients versus 11% in the placebo arm and elevation of serum lipase in 41% of sorafenib patients versus 30% in the placebo arm. Grade 4 pancreatitis was reported in two sorafenib patients, although both patients subsequently resumed sorafenib, with one at full dose. CONCLUSIONS: Sorafenib received FDA regular approval on December 20, 2005 for the treatment of advanced RCC based on the persuasive magnitude of improvement in PFS with acceptable safety. The recommended dose is 400 mg (two 200-mg tablets) twice daily taken either 1 h before or 2 h after meals. Adverse events were accommodated by temporary dose interruptions or reductions.

Approval summary: nelarabine for the treatment of T-cell lymphoblastic leukemia/lymphoma.

PURPOSE: To describe the clinical studies, chemistry manufacturing and controls, and clinical pharmacology and toxicology that led to Food and Drug Administration approval of nelarabine (Arranon) for the treatment of T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma. EXPERIMENTAL DESIGN: Two phase 2 trials, one conducted in pediatric patients and the other in adult patients, were reviewed. The i.v. dose and schedule of nelarabine in the pediatric and adult studies was 650 mg/m2/d daily for 5 days and 1,500 mg/m2 on days 1, 3, and 5, respectively. Treatments were repeated every 21 days. Study end points were the rates of complete response (CR) and CR with incomplete hematologic or bone marrow recovery (CR*). RESULTS: The pediatric efficacy population consisted of 39 patients who had relapsed or had been refractory to two or more induction regimens. CR to nelarabine treatment was observed in 5 (13%) patients and CR+CR* was observed in 9 (23%) patients. The adult efficacy population consisted of 28 patients. CR to nelarabine treatment was observed in 5 (18%) patients and CR+CR* was observed in 6 (21%) patients. Neurologic toxicity was dose limiting for both pediatric and adult patients. Other severe toxicities included laboratory abnormalities in pediatric patients and gastrointestinal and pulmonary toxicities in adults. CONCLUSIONS: On October 28, 2005, the Food and Drug Administration granted accelerated approval for nelarabine for treatment of patients with relapsed or refractory T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma after at least two prior regimens. This use is based on the induction of CRs. The applicant will conduct postmarketing clinical trials to show clinical benefit (e.g., survival prolongation).