Hypothalamic-Pituitary-Adrenal Axis Response in Patients With Acne Vulgaris Treated With Clascoterone.

BACKGROUND: Clascoterone cream 1% is a topical androgen receptor inhibitor approved to treat acne vulgaris in patients =>12 years of age. This report provides details of patients who developed laboratory signs of hypothalamic-pituitary-adrenal (HPA) axis suppression without clinical signs of adrenal suppression during the clascoterone development program. METHODS: Two open-label, multicenter, Phase 2 trials evaluated HPA axis suppression in patients with moderate-to-severe acne vulgaris. Study 1 (NCT01831960) enrolled cohorts of adults =>18 years of age and adolescents =>12 to <18 years of age. Study 2 (NCT02720627) enrolled adolescents 9 to <12 years of age. Patients applied clascoterone twice daily at maximum-exposure dosages for 14 days. Adrenal suppression was evaluated via cosyntropin stimulation test (CST) at baseline and day 14. Patients with an abnormal CST result (serum cortisol level =<18 µg/dL) had a follow-up CST approximately 4 weeks later. Blood was collected for pharmacokinetic analysis. Other safety assessments included adverse events (AEs), physical examination/vital signs, and electrocardiography. RESULTS: Overall, 5/69 clascoterone-treated patients had an abnormal CST result on day 14, including 1/20 adults, 2/22 patients aged =>12 to <18 years, and 2/27 patients aged 9 to <12 years. All patients had normal cortisol levels at follow-up testing approximately 4 weeks later. No relationship was observed between abnormal CST results and clascoterone plasma concentrations or the amount of study drug applied. No clinically relevant AEs or clinically significant changes in safety measures were observed in patients with adrenal suppression. CONCLUSION: Clascoterone induced laboratory evidence of mild, reversible HPA axis suppression under maximum-use exposure. J Drugs Dermatol. 2024;23(6):433-437.     doi:10.36849/JDD.7997.

Integrated Short-Term and Long-Term Efficacy of Topical Clascoterone Cream 1% in Patients Aged 12 Years or Older With Acne Vulgaris.

BACKGROUND: Clascoterone cream 1% is approved for the treatment of acne vulgaris in patients aged 12 years or older based on results from two identical pivotal Phase 3 trials. Integrated efficacy of clascoterone in patients aged 12 years or older with acne vulgaris from the pivotal trials (NCT02608450 and NCT02608476) and long-term extension (LTE) study (NCT02682264) is reported. METHODS: In the pivotal trials, patients with moderate-to-severe acne vulgaris were randomized 1:1 to twice-daily application of clascoterone cream 1% or vehicle for 12 weeks; they could then enter the LTE study, where all patients applied clascoterone to the face and, if desired, trunk for up to 9 additional months. Efficacy was assessed from treatment success based on Investigator's Global Assessment scores (IGA 0/1) in patients aged 12 years or older in the intention-to-treat population; lesion counts were assessed through week 12. Missing data were handled using multiple imputation in the pivotal studies and were not imputed in the LTE study. RESULTS: Of 1421 patients enrolled, 1143 (clascoterone, 576; vehicle, 567) completed week 12; 600 entered and 343 completed the LTE study. The treatment success rate and most lesion count reductions following clascoterone vs placebo treatment reached statistical significance at week 12; the overall treatment success rate increased to 30.2% for facial acne after 12 months and 31.7% for truncal acne after 9 months of treatment. CONCLUSIONS: The efficacy of clascoterone cream 1% for the treatment of acne vulgaris continued to increase over time for up to 12 months in patients aged 12 years or older with acne vulgaris.   J Drugs Dermatol. 2024;23(1):1278-1283.     doi:10.36849/JDD.7719.

Impact of Artificial Intelligence on Miss Rate of Colorectal Neoplasia.

BACKGROUND & AIMS: Artificial intelligence (AI) may detect colorectal polyps that have been missed due to perceptual pitfalls. By reducing such miss rate, AI may increase the detection of colorectal neoplasia leading to a higher degree of colorectal cancer (CRC) prevention. METHODS: Patients undergoing CRC screening or surveillance were enrolled in 8 centers (Italy, UK, US), and randomized (1:1) to undergo 2 same-day, back-to-back colonoscopies with or without AI (deep learning computer aided diagnosis endoscopy) in 2 different arms, namely AI followed by colonoscopy without AI or vice-versa. Adenoma miss rate (AMR) was calculated as the number of histologically verified lesions detected at second colonoscopy divided by the total number of lesions detected at first and second colonoscopy. Mean number of lesions detected in the second colonoscopy and proportion of false negative subjects (no lesion at first colonoscopy and at least 1 at second) were calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) were adjusted by endoscopist, age, sex, and indication for colonoscopy. Adverse events were also measured. RESULTS: A total of 230 subjects (116 AI first, 114 standard colonoscopy first) were included in the study analysis. AMR was 15.5% (38 of 246) and 32.4% (80 of 247) in the arm with AI and non-AI colonoscopy first, respectively (adjusted OR, 0.38; 95% CI, 0.23-0.62). In detail, AMR was lower for AI first for the ≤5 mm (15.9% vs 35.8%; OR, 0.34; 95% CI, 0.21-0.55) and nonpolypoid lesions (16.8% vs 45.8%; OR, 0.24; 95% CI, 0.13-0.43), and it was lower both in the proximal (18.3% vs 32.5%; OR, 0.46; 95% CI, 0.26-0.78) and distal colon (10.8% vs 32.1%; OR, 0.25; 95% CI, 0.11-0.57). Mean number of adenomas at second colonoscopy was lower in the AI-first group as compared with non-AI colonoscopy first (0.33 ± 0.63 vs 0.70 ± 0.97, P < .001). False negative rates were 6.8% (3 of 44 patients) and 29.6% (13 of 44) in the AI and non-AI first arms, respectively (OR, 0.17; 95% CI, 0.05-0.67). No difference in the rate of adverse events was found between the 2 groups. CONCLUSIONS: AI resulted in an approximately 2-fold reduction in miss rate of colorectal neoplasia, supporting AI-benefit in reducing perceptual errors for small and subtle lesions at standard colonoscopy. CLINICALTRIALS: gov, Number: NCT03954548.

Long-Term Safety and Efficacy of Twice-Daily Topical Clascoterone Cream 1% in Patients Greater Than or Equal to 12 Years of Age With Acne Vulgaris.

BACKGROUND: Clascoterone cream 1% is approved for the treatment of acne vulgaris in patients aged ≥ 12 years based on results from two 12-week Phase 3 studies in patients with moderate-to-severe acne. Safety and efficacy of clascoterone in patients aged ≥ 12 years from an open-label, long-term extension study are presented.  Methods: Enrolled patients applied clascoterone cream 1% twice daily to the entire face and, if desired by the patient and/or investigator, truncal acne, for up to 9 months. Patients achieving Investigator’s Global Assessment score of 0 or 1 (IGA 0/1) could stop treatment and resume if/when acne worsened. Safety was assessed from treatment-emergent adverse events (TEAEs) and local skin reactions (LSRs [telangiectasia, skin atrophy, striae rubrae, erythema, edema, scaling/dryness, stinging/burning, and pruritus]) in all treated patients. Efficacy was assessed from IGA at each visit among those completing the study per-protocol (PP); face and trunk were evaluated individually.  Results: Of 600 patients aged ≥ 12 years (original randomization: 311 clascoterone, 289 vehicle), 343 completed the extension study (177 clascoterone, 166 vehicle). There were 187 TEAEs in 108/598 clascoterone-treated patients (18.1%), including 56/311 (18.0%) and 52/287 (18.1%) patients originally randomized to clascoterone and vehicle, respectively; the most common LSRs (previous clascoterone/vehicle) were erythema (face, 8.0%/7.7%) and scaling/dryness (face, 10.0%/7.3%). The percentage of PP patients with facial and truncal IGA 0/1 increased to 48.9% (156/319) and 52.4% (65/124), respectively, at study end. CONCLUSIONS: Clascoterone cream 1% maintained a favorable safety and efficacy profile for up to 12 months in patients aged ≥ 12 years. Eichenfield LF, Hebert AA, Stein Gold L, et al. Long-term safety and efficacy of twice-daily topical clascoterone cream 1% in patients ≥ 12 years of age with acne vulgaris. J Drugs Dermatol. 2023;22(8):810-816. doi:10.36849/JDD.7592.

Efficacy and Safety of 1% Clascoterone Cream in Patients Aged > 12 Years With Acne Vulgaris.

BACKGROUND: Two randomized phase 3 studies evaluated efficacy and safety of 1% clascoterone cream, a topical androgen receptor inhibitor, in patients aged ≥9 years with moderate-to-severe facial acne vulgaris after 12 weeks of treatment. OBJECTIVES: To present a pooled data analysis of the efficacy and safety of 1% clascoterone cream after 12 weeks of treatment in patients aged ≥12 years from the 2 phase 3 trials. METHODS: Patients were randomized 1:1 to twice-daily treatment of the whole face with clascoterone or vehicle. Primary efficacy outcomes were proportion of patients achieving treatment success (Investigator Global Assessment score of "clear" [0] or "almost clear" [1] with ≥2-point reduction from baseline) and absolute change from baseline (CFB) in noninflammatory lesion count and inflammatory lesion count; secondary efficacy outcomes included absolute CFB in total lesion count at week 12. Safety was assessed from treatment-emergent adverse events and local skin reactions. RESULTS: 709/712 patients age ≥12 years were treated with clascoterone/vehicle. After 12 weeks, clascoterone was efficacious compared with vehicle, based on proportion of patients achieving treatment success (19.9% vs 7.7%) and CFB in noninflammatory lesion count (-20.8 vs -11.9), inflammatory lesion count (-19.7 vs -14.0), and total lesion count (-40.0 vs -26.1; all P<0.0001). Frequencies of local skin reactions were low and similar between treatment arms, with no new safety signals. CONCLUSIONS: Clascoterone is efficacious, with a favorable safety profile and low rates of local skin reactions in patients ≥12 years of age with facial acne vulgaris. (Clinicaltrials.gov NCT02608450 and NCT02608476) J Drugs Dermatol. 2023;22(2): doi:10.36849/JDD.7000.

Open-label, long-term extension study to evaluate the safety of clascoterone (CB-03-01) cream, 1% twice daily, in patients with acne vulgaris.

BACKGROUND: Androgens foster acnegenic pathways. OBJECTIVE: To assess the long-term safety of an androgen receptor inhibitor, clascoterone cream, 1%, in patients who participated in phase 3 studies. METHODS: Clascoterone cream was applied twice daily for up to 9 months to the face or trunk, or both. Treatment-emergent adverse events (TEAEs) and local skin reactions were evaluated at months 1, 3, 6, and 9, and at any unscheduled visit(s). The statistical analysis was performed using SAS Windows 9.3 software (SAS Institute Inc, Cary, NC). RESULTS: The study screened and enrolled 609 individuals (n = 317 clascoterone, n = 292 vehicle from original studies), and 347 completed the study (n = 179 clascoterone, n = 168 vehicle). Overall, 110 patients (18.1%) experienced 191 TEAEs. The most frequently reported TEAE was nasopharyngitis (n = 20). A total of 19 test article-related TEAEs occurred in 14 patients; of these, 9 experienced 9 TEAEs leading to discontinuation. There were 7 serious TEAEs in 6 individuals, but none were treatment related. One serious TEAE led to study discontinuation. Overall, treatment-emergent local skin reactions occurred in 18.1% (110 of 607). The most frequent local skin reactions on the face and trunk were erythema, scaling/dryness, and pruritus, and most were trace/minimal or mild in severity. LIMITATIONS: Long-term efficacy was not a primary end point. CONCLUSION: A low frequency of TEAEs over 9 months of clascoterone treatment was observed.

Cortexolone 17α-propionate (Clascoterone) Is a Novel Androgen Receptor Antagonist that Inhibits Production of Lipids and Inflammatory Cytokines from Sebocytes In Vitro

Cortexolone 17α-propionate (clascoterone) is a novel topical androgen antagonist that is being analyzed for its ability to treat acne. The pathogenesis of acne is attributed to multiple factors, including altered sebum production, inflammatory processes, dysregulation of the hormone microenvironment, and the proliferation of the skin commensal bacteria, Propionibacterium acnes (P. acnes). Androgens induce the proliferation and differentiation of sebocytes, (cells that comprise the sebaceous gland), help regulate the synthesis of the lipids that are incorporated into sebum and stimulate the production of cytokines that are found in inflammatory acne lesions. Several studies have established that clascoterone is a potent antiandrogen that is well tolerated and has selective topical activity. Its potency as an acne therapeutic is currently being analyzed in a large phase 3 clinical trial. The study described herein elucidates for the first time the mechanism of action of clascoterone. Clascoterone was found to bind the androgen receptor (AR) with high affinity in vitro, inhibit AR-regulated transcription in a reporter cell line, and antagonize androgen-regulated lipid and inflammatory cytokine production in a dose-dependent manner in human primary sebocytes. In particular, when compared to another AR antagonist, spironolactone, clascoterone was significantly better at inhibiting inflammatory cytokine synthesis from sebocytes. Therefore, clascoterone may be an excellent candidate to be the first topical antiandrogen to treat acne. J Drugs Dermatol. 2019;18(5):412-418.

Pharmacokinetic Profile, Safety, and Tolerability of Clascoterone (Cortexolone 17-alpha propionate, CB-03-01) Topical Cream, 1% in Subjects With Acne Vulgaris: An Open-Label Phase 2a Study

Clascoterone (cortexolone 17α-propionate, CB-03-01) 1% cream, a topical, androgen receptor (AR) inhibitor under investigation for the treatment of acne vulgaris, is rapidly metabolized to cortexolone in human plasma. The primary objectives of this study were to determine the pharmacokinetic (PK) properties and adrenal suppression potential of clascoterone topical cream, 1% in subjects with acne vulgaris. Study Design: This study was an open-label, multicenter study in 42 subjects ≥12 years of age with moderate-to-severe acne (Grade 3-4 on the Investigator's Global Assessment [IGA]), on the face, chest and/or back. Cohort 1(>18 years of age) and Cohort 2 (12-18 years of age) applied clascoterone topical cream, 1% twice daily (BID) for 14 days. Primary safety endpoints included hypothalamic-pituitary-adrenal (HPA) axis response to cosyntropin via a Cosyntropin Stimulation Test (CST) upon screening (day 1) and at day 14 (HPA axis suppression was defined as a post-stimulation serum cortisol level <18 µg/dL at day 14); and PK evaluation including concentration-time profiles of clascoterone and cortexolone in plasma­PK parameters were determined using "non-compartmental" analysis. Secondary safety endpoints included clinical laboratory testing, local and systemic adverse events (AEs), physical examination/vital signs, and electrocardiogram (ECG). Results: 42 subjects (Cohort 1=20, Cohort 2= 22) enrolled. Cohort 1 was comprised of 15 females (15/20, 75%) and 5 males (5/20, 25%), non-Hispanic/Latino (20/20, 100%), mean age is 24.4 years. Cohort 2 was comprised of 12 females (12/22, 54.5%) and 10 males (10/22, 45.5%), non-Hispanic/Latino (21/22, 95.5%), and mean age is 15.6 years. Three subjects (3/42,7%), 1 adult and 2 adolescents, demonstrated an abnormal HPA axis response with post-stimulation serum cortisol levels ranging from 14.9 to 17.7 µg/dL at day 14. All returned to normal HPA axis function, four weeks after day 14. None showed clinical evidence of adrenal suppression. Clascoterone plasma concentrations achieved PK steady-state by day 5. Clascoterone systemic exposure was similar between both cohorts. At steady-state, plasma concentrations increased ~1.8 to 2.1 fold versus first dose with mean (coefficient of variation [CV] %) maximum plasma concentrations of 4.4 ng/mL (67%) and 4.6 ng/mL (103%) in Cohort 1 and Cohort 2, respectively. Cortexolone plasma concentrations trended below the lower limit of quantitation (0.5 ng/mL) in both cohorts. Local skin reactions (LSRs) were mostly mild, with only one moderate case of pruritus. There were nine AEs categorized as follows: definitely related (N=2), probably related (N=4), unlikely/not related (N=3), to clascoterone. Conclusion: This study demonstrates the safety and tolerability of clascoterone topical cream, 1% in adolescents and adults with acne vulgaris treated BID for 14 consecutive days. J Drugs Dermatol. 2019;18(6):563-568.

A Phase 2b, Randomized, Double-Blind Vehicle Controlled, Dose Escalation Study Evaluating Clascoterone 0.1%, 0.5%, and 1% Topical Cream in Subjects With Facial Acne

Androgens play a key role in acne pathogenesis in both males and females. Clascoterone (CB-03-01, Cortexolone 17α propionate) cream is a topical anti-androgen under investigation for the treatment of acne. The results from a phase 2b dose escalating study are discussed. Methods: Primary objective: to compare the safety and efficacy of topical creams containing clascoterone 0.1% (twice daily [BID]), 0.5% (BID), or 1% (daily [QD] or BID) versus vehicle (QD or BID) in male and female subjects ≥12 years with facial acne vulgaris. Efficacy was assessed by: Investigator's Global Assessment (IGA)--the overall severity of acne using a five-point scale (from 0=clear to 4=severe); inflammatory and non-inflammatory acne lesion counts (ALC); and subject satisfaction with treatment--subjects assessed overall treatment satisfaction using a 4-point scale. Safety assessments: local and systemic adverse events (AEs), physical examination/vital signs, laboratory tests, local skin reactions (LSRs), and electrocardiograms (ECGs). Treatment success required a score of "clear" or "almost clear" (IGA score of 0 or 1) and a two or more-grade improvement from baseline. Results: 363 subjects (N=72, 0.1% BID; N=76, 0.5% BID; N=70, 1% QD; N=70, 1% BID; and N=75, vehicle QD or BID) enrolled. 304 subjects (83.7%) completed the study. Intention to Treat (ITT) population: 196/363 (54.0%) females; 167/363 46.0%) males; (257/363 (70.2%) were white; average age=19.7 years. Demographic and baseline characteristics were similar across all groups. Treatment success at week 12 were highest for the 1% BID (6/70, 8.6%) and 0.1% BID (6/72, 8.3%) groups versus vehicle (2/75, 2.7%). Absolute change in inflammatory (P=0.0431) and non-inflammatory (P=0.0303) lesions was statistically significant among the treatment groups. The median change from baseline at week 12 in inflammatory and non-inflammatory lesions was greatest in the 1% BID group -13.5 and -17.5, respectively. Similar results were observed for the secondary efficacy endpoints whereby the highest success rate and greatest reduction in lesion counts from baseline to week 12 occurred with 1% BID. 93/363 subjects (25.6%) reported ≥1 AEs; total number of AEs=123 with 2 probably/possibly related to treatment (N=1, 1% QD group). Subjects with ≥1AEs: 0.1% BID=25.0%, 0.5% BID=38.2%, 1% QD=22.9%, 1% BID=18.6%, and vehicle=22.7%. AEs were mostly mild in severity and similar across all groups. Most AEs (93/121 76.8%) resolved by the end of the study. Erythema was the most prevalent LSR; 36.8% had at least minimal erythema at some point during the study. Conclusions: All clascoterone cream concentrations were well tolerated with no clinically relevant safety issues noted. Clascoterone 1% BID treatment had the most favorable results and was selected as the best candidate for further clinical study and development. Two Phase 3 investigations of clascoterone topical cream, 1% for the treatment of moderate-to-severe acne vulgaris in individuals ≥9 years recently concluded. J Drugs Dermatol. 2019;18(6):570-575.

Cortexolone 17α-Propionate (Clascoterone) is an Androgen Receptor Antagonist in Dermal Papilla Cells In Vitro

Cortexolone 17α-propionate (clascoterone) is a novel androgen antagonist that is currently being analyzed in a large phase 2 clinical trial for the topical treatment of androgenetic alopecia (AGA). While the pathogenesis of AGA is still debated, the consensus is that AGA is an androgen-dependent hair disorder with strong genetic links, and that the testosterone metabolite, dihydrotestosterone (DHT), plays a causal role in its development. DHT binds to the androgen receptor (AR) in scalp dermal papilla cells (DPC) to induce AR-mediated transcription of genes that contribute to AGA in genetically predisposed individuals. Several studies have established that clascoterone is a potent antiandrogen that is well tolerated and has selective topical activity. The study described herein elucidates a potential mechanism of clascoterone in AGA. Clascoterone was found to inhibit AR-regulated transcription in a reporter cell line with similar efficacy to the 5α-reductase inhibitor, finasteride. More importantly, when compared with another direct AR antagonist, enzalutamide, clascoterone was significantly better at inhibiting IL-6 synthesis from DHT-stimulated primary cultures of human scalp DPC. Therefore, clascoterone may be an excellent candidate to be the first topical antiandrogen for treating AGA. J Drugs Dermatol. 2019;18(2):197-201.

Once-daily budesonide MMX in active, mild-to-moderate ulcerative colitis: results from the randomised CORE II study.

OBJECTIVE: Budesonide MMX is a novel oral formulation of budesonide that uses Multi-Matrix System (MMX) technology to extend release to the colon. This study compared the efficacy of budesonide MMX with placebo in patients with active, mild-to-moderate ulcerative colitis (UC). DESIGN: Patients were randomised 1:1:1:1 to receive budesonide MMX 9 mg or 6 mg, or Entocort EC 9 mg (budesonide controlled ileal-release capsules; reference arm) or placebo once daily for 8 weeks. The primary endpoint was combined clinical and endoscopic remission, defined as UC Disease Activity Index score ≤1 with a score of 0 for rectal bleeding and stool frequency, no mucosal friability on colonoscopy, and a ≥1-point reduction in endoscopic index score from baseline. RESULTS: 410 patients were evaluated for efficacy. Combined clinical and endoscopic remission rates with budesonide MMX 9 mg or 6 mg, Entocort EC and placebo were 17.4%, 8.3%, 12.6% and 4.5%, respectively. The difference between budesonide MMX 9 mg and placebo was significant (OR 4.49; 95% CI 1.47 to 13.72; p=0.0047). Budesonide MMX 9 mg was associated with numerically higher rates of clinical (42.2% vs 33.7%) and endoscopic improvement (42.2% vs 31.5%) versus placebo. The rate of histological healing (16.5% vs 6.7%; p=0.0361) and proportion of patients with symptom resolution (23.9% vs 11.2%; p=0.0220) were significantly higher for budesonide MMX 9 mg than placebo. Adverse event profiles were similar across groups. CONCLUSION: Budesonide MMX 9 mg was safe and more effective than placebo at inducing combined clinical and endoscopic remission in patients with active, mild-to-moderate UC.

Once-daily budesonide MMX® extended-release tablets induce remission in patients with mild to moderate ulcerative colitis: results from the CORE I study.

BACKGROUND & AIMS: Budesonide is a corticosteroid with minimal systemic corticosteroid activity due to first-pass hepatic metabolism. Budesonide MMX® is a once-daily oral formulation of budesonide that extends budesonide release throughout the colon using multi-matrix system (MMX) technology. METHODS: We performed a randomized, double-blind, double-dummy, placebo-controlled trial to evaluate the efficacy of budesonide MMX for induction of remission in 509 patients with active, mild to moderate ulcerative colitis (UC). Patients were randomly assigned to groups that were given budesonide MMX (9 mg or 6 mg), mesalamine (2.4 g, as reference), or placebo for 8 weeks. The primary end point was remission at week 8. RESULTS: The rates of remission at week 8 among subjects given 9 mg or 6 mg budesonide MMX or mesalamine were 17.9%, 13.2%, and 12.1%, respectively, compared with 7.4% for placebo (P = .0143, P = .1393, and P = .2200). The rates of clinical improvement at week 8 among patients given 9 mg or 6 mg budesonide MMX or mesalamine were 33.3%, 30.6%, and 33.9%, respectively, compared with 24.8% for placebo (P = .1420, P = .3146, and P = .1189). The rates of endoscopic improvement at week 8 among subjects given 9 mg or 6 mg budesonide MMX or mesalamine were 41.5%, 35.5%, and 33.1%, respectively, compared with 33.1% for placebo. The rates of symptom resolution at week 8 among subjects given 9 mg or 6 mg budesonide MMX or mesalamine were 28.5%, 28.9%, and 25.0%, respectively, compared with 16.5% for placebo (P = .0258, P = .0214, and P = .1025). Adverse events occurred at similar frequencies among groups. CONCLUSIONS: Budesonide MMX (9 mg) was safe and more effective than placebo in inducing remission in patients with active, mild to moderate UC.

In vitro activity and single-step mutational analysis of rifamycin SV tested against enteropathogens associated with traveler's diarrhea and Clostridium difficile.

Rifamycin SV is a broad-spectrum, poorly absorbed antimicrobial agent that, when coupled with MMX technology, is being targeted for the oral treatment of traveler's diarrhea (TD) and Clostridium difficile-associated disease (CDAD). Rifamycin SV was tested for activity against 911 TD-associated enteropathogens and 30 C. difficile isolates collected from several global surveillance studies. Rifamycin SV demonstrated similar antimicrobial activity levels against the Enterobacteriaceae, with MIC50 values ranging from 32 to 128 µg/ml for all but one strain (an enterotoxigenic Escherichia coli at >512 µg/ml). For non-Enterobacteriaceae strains, MIC50 values ranged from 2 to 8 µg/ml, with the exception of Campylobacter spp., for which all strains had MIC values of >512 µg/ml. Rifamycin SV also demonstrated excellent activity (MIC50 of ≤ 0.03 µg/ml) against most C. difficile strains (including one hypervirulent NAP1 strain), and this activity was even superior to the potency observed for vancomycin, metronidazole, and rifaximin. In mutational passaging studies, rifamycin SV induced stable resistance and showed a mutation frequency in E. coli similar to that of rifampin. This study presents the potency of rifamycin SV for enteropathogens commonly recovered from patients with TD and CDAD. Additional in vitro and in vivo studies appear necessary to determine the utility of rifamycin SV as an oral agent for the prevention and treatment of TD and CDAD.

Pharmacokinetics and Safety of Rifamycin SV after Single and Multiple Doses of MMX® Modified Release Tablets in Healthy Male and Female Volunteers.

The primary objective of this single- and multiple-dose pharmacokinetic study was the investigation of rifamycin SV's pharmacokinetic profile in plasma and urine. All the 18 enrolled healthy men and post-menopausal women received modified release tablets containing 600 mg of the oral non-absorbable antibiotic, rifamycin SV, according to a multiple dose regimen: one tablet three times a day (daily intake: 1800 mg) for 14 consecutive days. Blood sampling and urine collection were performed up to 24 h post-dose after the first dose on Days 1 and 7. On average, on Day 1, Cmax,0-24 was 5.79 ± 4.24 ng/mL and was attained in a median time of 9 h. On Day 7, all the subjects had quantifiable levels of rifamycin SV in plasma at each sampling time. After a peak concentration attained 2 h post-dose (mean ± SD concentration: 10.94 ± 16.41 ng/mL), rifamycin SV decreased in plasma to levels similar to those of Day 1. The amounts of rifamycin SV excreted in urine paralleled the plasma concentration at the corresponding times. On Day 1, the total amount excreted in urine was 0.0013%, and was 0.0029% on Day 7. The study results confirmed those of the previous Phase I study: the systemic absorption of rifamycin SV was also proved negligible after 7 days of the 600 mg t.i.d. dose regimen of the newly formulated tablets, currently under development for the treatment of several small and large intestinal pathologies, including diarrhea-predominant irritable bowel syndrome, hepatic encephalopathy, and others. Registered at ClinicalTrials.gov with the identifier NCT02969252, last updated on 26JAN18.

The Dual Androgen Receptor and Glucocorticoid Receptor Antagonist CB-03-10 as Potential Treatment for Tumors that have Acquired GR-mediated Resistance to AR Blockade.

CB-03-10 (cortexolone 17α-valerate-21-propionate) is a synthetic steroidal compound derived from cortexolone (11-deoxycortisone), an intermediate in cortisol biosynthesis. Characterization of the activity of CB-03-10 and its main related compound CB-03-05 (cortexolone 17α-valerate) included in vitro binding to the androgen and glucocorticoid receptors (AR and GR), antagonism of AR and GR transcriptional activities, and screening for antitumor activity across a selected panel of human prostate and in triple-negative breast cancer cell lines. CB-03-10 cytotoxic activity in these cancer cell lines was in the low micromolar range and was primarily associated with induction of the apoptotic cascade via activation of caspases. The compound's potential for antitumor activity was verified in a murine xenograft model utilizing the AR-positive LNCaP prostate cancer cell line as well as in an orthotopic model utilizing AR-negative/GR-positive MDA-MB-231 breast cancer cell line. Orally administered CB-03-10 inhibited prostate tumor growth and orthotopically implanted breast tumor growth in these mice and maintained body weight, as compared with vehicle-treated mice. On the basis of AR/GR binding affinities, antagonism of androgen and glucocorticoid-dependent transcriptional activities, and AR/GR mRNA and protein expression, the mechanism of tumor growth suppression is related to AR and GR antagonist activities. Importantly, these compounds lack biologically relevant AR/GR agonist activities. Overall, these preclinical findings support the selection of CB-03-10 for further development as an anticancer agent in cases where resistance to AR-targeted therapy or chemotherapy, via upregulation of GR activity, continues to limit the efficacy and duration of clinical benefit with these interventions.

Rifamycin SV exhibits strong anti-inflammatory in vitro activity through pregnane X receptor stimulation and NFκB inhibition.

Rifamycin SV (rifamycin), is a member of the ansamycin family of antimicrobial compounds which kills bacteria commonly associated with infectious diarrhea and other enteric infections. Rifamycin has been found to be effective in experimental animal models of gut inflammation and its efficacy in these settings has been attributed partially to immunomodulatory non-bactericidal activities. This study aimed to further evaluate the anti-inflammatory activities of rifamycin by analyzing its effect on two key regulators of inflammation: PXR and NFκB. Rifamycin stimulated PXR transcriptional activity in two PXR reporter cell lines and induced expression of two genes known to be regulated by PXR and are directly involved in cellular detoxification: CYP3A4 and PgP. Moreover, CYP3A4 metabolic activity was induced by rifamycin in HepG2 cells. Rifamycin also antagonized TNFα and LPS-induced NFκB activities and inhibited IL1ß-induced synthesis of inflammatory chemokine, IL8. Although reciprocal regulation of PXR and NFkB by rifamycin was not directly addressed, the data suggest that in the absence of PXR, inhibition of NFκB by rifamycin is not dependent on PXR stimulation. Thus, rifamycin exhibits potent anti-inflammatory activities, characterized by in vitro PXR activation and concomitant CYP3A4 and PgP induction, in parallel with potent NFκB inhibition and concomitant IL8 inhibition.

Release of 5-aminosalicylate from an MMX mesalamine tablet during transit through a simulated gastrointestinal tract system.

5-Aminosalicylate (5-ASA; mesalamine) is the current first-line treatment for mild to moderate ulcerative colitis, a chronic inflammatory condition that most commonly affects the distal part of the colon. MMXtrade mark mesalamine (Lialdatrade mark [US]; Mezavanttrade mark XL [UK and Ireland]; Mezavanttrade mark [elsewhere]; Shire Pharmaceuticals Inc., Wayne, Pa, under license from Giuliani SpA, Milan, Italy) was created to be a novel, once-daily 5-ASA formulation. MMX mesalamine in tablet form has a pH-dependent, gastroresistant coating and is designed to delay the release of 5-ASA during transit through the upper gastrointestinal tract; it consists of hydrophilic and lipophilic excipients that are designed to prolong the release of 5-ASA throughout the colon. The release kinetics of 5-ASA from an MMX mesalamine tablet were assessed with the use of a dynamic in vitro gastrointestinal tract system (TNO GastroIntestinal Model) that simulates physiologic conditions in the adult human gastrointestinal tract under standardized fed and fasted conditions. This system incorporates removal of released drug via dialysis and automated sampling taken at various sections of the system. Less than 1% of 5-ASA was found to be released from the tablet in the simulated stomach and small intestine (before introduction into the simulated colon). Most of the 5-ASA within each tablet was released in the simulated colon (fasted state conditions: 78.0%; fed state conditions: 68.5%). Substantial quantities were released during the 8- to 18-hour sampling period (49.6 mg/h[fasted] and 40.7 mg/h [fed]). In conclusion, with the use of an in vitro system, the investigators showed that 5-ASA release from an MMX mesalamine tablet was delayed until the tablet reached the simulated colon. Throughout the simulated colon, release of 5-ASA from an MMX mesalamine tablet was prolonged.

Bisphosphonates activate nucleotide receptors signaling and induce the expression of Hsp90 in osteoblast-like cell lines.

Bisphosphonates are the most important drugs used in the treatment of osteoporosis as they inhibit osteoclast resorption and stimulate proliferation of osteoblasts. However, the molecular mechanisms responsible for these effects are still poorly elucidated. It is known that nucleotide receptors-mediated signaling plays a central role in modulating osteoblasts growth in response to mechanical stress. By using osteoblast-like cell lines (i.e., HOBIT, MG-63, ROS P2Y), which express P2Y receptors, we found that the treatment with risedronate promotes non-lytic ATP release leading to activation of ERKs through the involvement of P2Y receptors triggering. A major role in this signal transduction pathway seems to be the involvement of P2Y(1) and P2Y(2) receptors, since the stimulatory effect of risedronate on ERKs is not appreciable in ROS 17/2.8 cells, which do not express these two receptors. Differential proteomics analysis identified Hsp90 upregulation as a result of risedronate effect on HOBIT and MG-63 cells. The stimulatory effect is dependent on ERKs activation involving nucleotide receptors triggering and leads to increased proliferation of osteoblast-like cells. In fact, functional inactivation of Hsp90 by the specific inhibitor 17-AAG prevents the bisphosphonate-induced mitogenic effects in osteoblasts. These findings show that bisphosphonates, by inducing ATP release, may also act through nucleotide receptors signaling leading to ERKs activation and may exert their mitogenic role on osteoblasts through the involvement of Hsp90.

High prevalence of asymptomatic vertebral fractures in post-menopausal women receiving chronic glucocorticoid therapy: a cross-sectional outpatient study.

Glucocorticoid (GC)-induced osteoporosis mostly affects trabecular bone of vertebrae. Only 30% of vertebral fractures are symptomatic, yet both clinical and radiological vertebral fractures have been associated with increased mortality and morbidity. The aims of this cross-sectional, outpatient-based study were to measure the prevalence of asymptomatic vertebral fractures in a large sample of post-menopausal women given GCs for different diseases; to compare prevalence of asymptomatic vertebral fractures according to disease, GC treatment and major risk factors; and to assess the quality of life in GC users with and without asymptomatic vertebral fractures. 551 patients referring to 39 centers as outpatients for their programmed follow-up and satisfying the inclusion criteria were included in the analysis. Each patient underwent structured medical interview (including dose and duration of GC therapy, major risk factors for osteoporosis, the quality of life questionnaire of the European Foundation for Osteoporosis (QUALEFFO) and a back function score questionnaire), thoraco-lumbar radiographs and subsequent morphometry; for 253 and 437 patients, respectively, lumbar spine bone mineral density (BMD) assessed by dual energy X-ray absorptiometry and calcaneal bone stiffness assessed by quantitative ultrasonometry were available. The prevalence of asymptomatic vertebral fractures resulted >37%, with >14% of patients having two or more asymptomatic vertebral fractures and was much higher than that found in epidemiological studies on healthy women. Distribution of asymptomatic vertebral fractures along the spine showed a bimodal pattern, with two peaks at T7 and T11. The prevalence of asymptomatic vertebral fractures clearly increased with age. Differences in prevalence among diseases were evidenced. When controlled for age, GC cumulative dose, duration of therapy and personal history of fractures, the adjusted prevalences were 30.77% for systemic lupus erythematosus, 33.78% for rheumatoid arthritis, 37.78% for asthma/chronic obstructive pulmonary disease, 43.20% for polymyalgia rheumatica and 43.36% for diseases grouped as "other vasculitides/connective tissue diseases". No significant association was found with GC cumulative dose and duration of therapy. Established risk factors for osteoporosis (except for age, years since menopause and personal history of fractures), lumbar spine BMD, calcaneal stiffness and QUALEFFO score were not associated with number and severity of asymptomatic vertebral fractures. Underlying disease is likely to contribute to the risk of fracture, but disease by itself could not be dissected from GC regimen. Vertebral fractures should be looked for carefully in all post-menopausal women receiving long-term systemic GCs since they can be asymptomatic and are scarcely predictable.