The efficacy and tolerability of tazarotene foam, 0.1%, in the treatment of acne vulgaris in 2 multicenter, randomized, vehicle-controlled, double-blind studies.

BACKGROUND: Tazarotene 0.1% gel and cream are effective topical treatments for acne. Tazarotene foam, 0.1% was developed to provide an alternative, safe, and effective formulation. OBJECTIVE: To evaluate efficacy and tolerability of tazarotene foam, 0.1% in adults and adolescents with acne vulgaris. METHODS: Two randomized, double-blind, vehicle-controlled, parallel-group studies were conducted at 39 centers in the United States and Canada. The first study involved 744 participants and the second 742, aged 12 to 45 years, who were randomized to receive treatment with either tazarotene foam, 0.1% or vehicle foam once daily for 12 weeks. Lesion counts, Investigator's Static Global Assessments (ISGA), and Subject's Global Assessments (SGA) were evaluated at baseline and weeks 2, 4, 8, and 12. Tolerability was monitored throughout the study. RESULTS: At week 12 in both studies, treatment with tazarotene foam led to greater decreases from baseline in mean absolute and percentage change in lesion counts (noninflammatory, inflammatory, and total), greater proportion of participants with ≥2-grade improvement in ISGA score, and greater proportion of participants with ISGA score of 0 or 1 than vehicle treatment (P<.001 for all). Only application-site skin irritation and dryness were reported by >5% of participants in active treatment groups in both studies. LIMITATIONS: The efficacy and tolerability of tazarotene foam were not compared directly with those of other formulations. CONCLUSION: Tazarotene foam, 0.1% significantly reduced the number and severity of acne lesions after 12 weeks and had a safe and acceptable tolerability profile.

Tazarotene foam versus tazarotene gel: a randomized relative bioavailability study in acne vulgaris.

BACKGROUND AND OBJECTIVE: Tazarotene, a retinoid pro-drug, is available in gel, cream and foam for the topical treatment of acne vulgaris. This single-centre, randomized, open-label study assessed relative bioavailability of its active metabolite tazarotenic acid after dosing of tazarotene foam or gel. STUDY DESIGN AND METHODS: Subjects with moderate-to-severe acne received a mean, once-daily dose of 3.7 g tazarotene foam or gel applied to face, chest, upper back and shoulders. Blood samples were collected pre-dose on multiple days and multiple time points over a 72-h period to measure plasma tazarotenic acid and tazarotene. RESULTS: Mean tazarotenic acid area under the plasma concentration-time curve (AUC) and maximum measured plasma concentration (Cmax) values were significantly higher for gel versus foam. Cmax occurred within 5-6 h after dosing, with an apparent terminal elimination half-life (t½) of 18-22 h. Accumulation was observed upon repeated dosing with steady-state conditions achieved at day 20. Mean tazarotene concentrations were also higher following gel application versus foam. Both foam and gel demonstrated an acceptable safety profile. CONCLUSION: Tazarotene foam, 0.1 % is an alternative to gel with less systemic exposure.

Androgen receptor mutations in androgen-independent prostate cancer: Cancer and Leukemia Group B Study 9663.

PURPOSE: The mechanisms responsible for prostate cancer androgen independence are diverse. Mutations of the androgen receptor (AR) gene that broaden ligand specificity have been implicated. Bone marrow specimens containing prostate tumor were obtained from men undergoing antiandrogen withdrawal for AR sequence analysis and clinical correlation. MATERIALS AND METHODS: Eligible men enrolled on a trial of antiandrogen withdrawal had a minimum prostate-specific antigen (PSA) level of 5 ng/dL that was increasing on castration therapy including an antiandrogen. With informed consent, marrow biopsies were obtained to collect prostate tumor. Additional samples were obtained from men enrolled on chemotherapy trials. AR cDNA or DNA was polymerase chain reaction-amplified, cloned, and sequenced. The AR CAG repeat length was recorded. RESULTS: One hundred eighty-four bone marrow biopsies were obtained, and 48 had prostate tumor detected by light microscopy. The ARs from these 48 samples were sequenced. Overall, five (10%) of 48 tumors had mutated ARs. AR point mutations were detected in the hormone-binding domain involved in transcription factor binding. Three mutations were novel in prostate cancer. One tumor sample had a CAG repeat length of 21, compared with germline length of 22 repeats. There was no association between detectability of AR mutations and antiandrogen withdrawal response or survival. CONCLUSION: These data suggest that AR mutations are present in approximately 10% of patients with prostate cancer who experience treatment failure with hormone therapy that included an antiandrogen. Mutations in the AR likely confer a growth advantage for a subset of progressive prostate cancers. Correlation of AR mutation with antiandrogen withdrawal response or survival could not be made.