Difamilast Ointment in Japanese Adult and Pediatric Patients with Atopic Dermatitis: A Phase III, Long-Term, Open-Label Study.

INTRODUCTION: Phosphodiesterase 4 (PDE4), which regulates inflammatory cytokine production leading to atopic dermatitis (AD), is selectively inhibited by difamilast. The objective of this phase III, long-term, open-label study was to evaluate the safety and efficacy of topical difamilast in Japanese adult and pediatric patients with AD. METHODS: Adult patients (n = 166) began treatment with difamilast 1% ointment, and pediatric patients began treatment with difamilast 0.3% ointment (n = 144) or difamilast 1% ointment (n = 56). Treatment was continued twice daily for 52 weeks. All patients had an Investigator's Global Assessment (IGA) score of 2 (mild), 3 (moderate), or 4 (severe/very severe), and an AD-affected body surface area (BSA) of ≥ 5% before treatment, with no restriction on the upper limit for the AD-affected BSA. RESULTS: During therapy, 120 adult patients (72.3%) and 178 pediatric patients (89.0%) experienced treatment-emergent adverse events (TEAEs), most of which were mild or moderate in severity. Discontinuation due to TEAEs was reported in 13 adult patients (7.8%) and in 7 pediatric patients (3.5%). Treatment-related adverse events were reported in 14 adult patients (8.4%) and 16 pediatric patients (8.0%), most frequently dermatitis atopic (1.8%) and acne (1.2%) in adult patients and dermatitis atopic and pigmentation disorder (each 2.0%) in pediatric patients. The cumulative success rates in Eczema Area and Severity Index (EASI)-75 in adult and pediatric patients were 55.4% and 73.5%, respectively, at week 52, and the cumulative success rates increased from week 4 to week 52. The cumulative success rates in IGA score showed the same trend as those in EASI -75. CONCLUSIONS: This study demonstrates that difamilast ointments are well tolerated and effective in Japanese adult and pediatric patients with AD when applied twice daily for 52 weeks, and are expected to be used for a long-term treatment for AD. CLINICAL TRIAL REGISTRATION: Clinical Trials.gov identifier: NCT03961529.

Difamilast ointment in adult patients with atopic dermatitis: A phase 3 randomized, double-blind, vehicle-controlled trial.

BACKGROUND: Difamilast is a selective phosphodiesterase 4 inhibitor. Phosphodiesterase 4 is involved in cytokine production linked with inflammatory disorders, including atopic dermatitis. OBJECTIVE: To demonstrate the superiority of difamilast ointment 1% to vehicle in adult Japanese patients with atopic dermatitis. METHODS: In this phase 3, randomized, double-blind trial, patients aged 15-70 years with an investigator global assessment score of 2 or 3 received topical difamilast ointment 1% (n = 182) or a vehicle (n = 182) twice daily for 4 weeks. RESULTS: The success rate in investigator global assessment score at week 4 (primary endpoint)-the percentage of patients achieving an investigator global assessment score of 0 or 1 with ≥2-grade improvement-was significantly higher with 1% difamilast than with the vehicle (38.46% vs 12.64%, respectively, P < .0001). The success rates in ≥50%, ≥75%, and ≥90% improvement in overall eczema area and severity index score at week 4 followed the same trend. Difamilast at 1% provided significant mean percent improvement from baseline in overall eczema area and severity index score versus vehicle from week 1 to 4. Treatment-emergent adverse events were mostly mild or moderate and less frequent with difamilast. LIMITATIONS: Study treatment was limited to 4 weeks. CONCLUSION: Difamilast ointment 1% demonstrated superiority to the vehicle and favorable safety in adult Japanese patients with atopic dermatitis.

Phase 2, randomized, double-blind, placebo-controlled, 4-week study to evaluate the safety and efficacy of OPA- 15406 (difamilast), a new topical selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients aged 2-14 years with atopic dermatitis.

The safety and efficacy of OPA-15406 (international non-proprietary name, difamilast; also referred to as MM36), a new topical, selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients with atopic dermatitis aged 2-14 years were evaluated in a phase 2, randomized, double-blind, vehicle-controlled, 4-week study. Seventy-three patients were randomized 1:1:1 to receive OPA-15406 0.3%, OPA-15406 1% or vehicle ointment twice daily for 4 weeks. The mean age of patients was similar across treatment groups. No deaths or serious treatment-emergent adverse events were reported; all treatment-emergent adverse events were mild or moderate in severity. The incidence of treatment-emergent adverse events leading to treatment discontinuation was 4.2% (1/24) in the OPA-15406 0.3% group, 4.0% (1/25) in the OPA-15406 1% group and 16.7% (4/24) in the vehicle group, all of which were worsening of atopic dermatitis. Both OPA-15406 groups demonstrated a higher incidence of success in the Investigator Global Assessment score compared with the vehicle group over the 4-week study. The OPA-15406 groups also showed greater improvements from baseline compared with the vehicle group in the Investigator Global Assessment score, Eczema Area and Severity Index overall score and subscale (erythema, induration/papulation, excoriation and lichenification) scores, Visual Analog Scale pruritus score, Patient-Oriented Eczema Measure score, and percentage of affected body surface area over the 4-week study. Topical OPA-15406 twice daily for 4 weeks was considered a safe and effective treatment option in this phase 2 study in pediatric patients with atopic dermatitis, and phase 3 development is currently ongoing.

Efficacy and safety of topical OPA-15406, a new phosphodiesterase 4 inhibitor, in Japanese patients with atopic dermatitis for 8 weeks: A phase 2, randomized, double-blind, placebo-controlled study.

The efficacy and safety of topical OPA-15406, a new phosphodiesterase 4 inhibitor, were examined in Japanese patients aged 15-70 years with atopic dermatitis in a phase 2, randomized, double-blind, vehicle-controlled study. Two hundred patients were randomized to three treatment groups at a 1:1:1 ratio to receive OPA-15406 0.3%, OPA-15406 1% or vehicle ointment twice daily for 8 weeks. The OPA-15406 1% group was superior to the vehicle group in terms of the incidence of success based on the Investigator Global Assessment score at week 4 (P = 0.0328), which was the primary end-point, while the OPA-15406 0.3% group showed a trend toward improvement in the primary end-point. The mean Eczema Area and Severity Index total score and subscale (erythema, induration/papulation, excoriation and lichenification) scores, the Visual Analog Scale pruritus score and the Patient-Oriented Eczema Measure score were significantly improved and the percentage of affected body surface area was significantly decreased in both OPA-15406 groups relative to the vehicle group as early as week 1, and the improved scores and decreased percentages were generally maintained until week 8. No deaths or serious treatment-emergent adverse events occurred in the OPA-15406 treatment groups. Treatment-emergent adverse events frequently observed across treatment groups were worsening of atopic dermatitis, viral upper respiratory tract infection and pruritus, all of which were mild or moderate in severity in the OPA-15406 groups. OPA-15406 1% ointment showed favorable efficacy and safety profiles, indicating a promising treatment option for patients with atopic dermatitis.

Long-term safety profile of tolvaptan in autosomal dominant polycystic kidney disease patients: TEMPO Extension Japan Trial.

AIM: The aim of this trial (ClinicalTrials.gov identifier: NCT01280721) was to investigate the long-term safety profile of tolvaptan in Japanese patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS: This open-label multicenter trial was conducted to examine adverse drug reactions (ADRs) related to tolvaptan up to an additional 3 years in 135 Japanese patients who participated in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and its Outcomes (TEMPO) 3:4 trial at doses of 60-120 mg/d. Blood samples were collected at baseline; at weeks 1, 2, and 3; at month 3; and every 3 months thereafter. RESULTS: In total, 134/135 (>99%) patients experienced ADRs. The most frequent ADRs were thirst (77.0%), pollakiuria (57.0%), polyuria (37.8%), and hyperuricemia (14.8%). Any unexpected ADRs were not reported in this trial. Most ADRs occurred early during treatment. Fourteen patients (10.4%) experienced hepatic events, and 8 (5.9%) experienced >3-fold increases above the upper limits of normal in serum alanine aminotransferase or aspartate aminotransferase levels between 3 and 9 months following tolvaptan initiation, which recovered after drug interruption. Of the 8 patients, 7 (5.2%) were previously allocated to the placebo arm in the TEMPO 3:4 trial and 4 (3.0%) discontinued due to the hepatic events. One patient (0.7%) was previously allocated to tolvaptan and experienced similar events in the TEMPO 3:4 trial. None of the hepatic ADRs met Hy's Law laboratory criteria. CONCLUSION: ADRs observed in this extension trial were similar to those identified in the TEMPO 3:4 trial and hepatic events were not progressive.

Predictive factors of the pharmacological action of tolvaptan in patients with liver cirrhosis: a post hoc analysis.

BACKGROUND: Tolvaptan has been approved in Japan for the treatment of hepatic edema. An important consideration in providing a clinical benefit to patients with liver cirrhosis is the improvement of ascites-related clinical symptoms. In the present post hoc analysis, we aimed to identify factors that were predictive of the potency of tolvaptan, and to examine the relationship between changes in initial urine volume and improvement in ascites-related clinical symptoms. METHODS: This post hoc analysis was based on three previous phase 2 and 3 clinical trials of tolvaptan in patients with liver cirrhosis. Predictive factors associated with a change in initial urine volume were identified. A change of ≥500 mL from baseline confirmed the pharmacological action of tolvaptan treatment. The relationship between the change in initial urine volume and improvement in ascites-related clinical symptoms was also examined. RESULTS: A total of 152 patients were enrolled in this study. Body weight and BUN were identified as predictive parameters. Among patients with a change in initial urine volume of ≥500 mL, 75 % demonstrated improvement in ascites-related clinical symptoms, while no improvement was seen in those with a change of <500 mL. None of the patients with initial urine volume of <500 mL showed resolution of symptoms. CONCLUSIONS: Change in urine volume was affected by both baseline body weight and BUN in tolvaptan-treated subjects. Higher urine output was associated with improvements in ascites-related clinical symptoms.

Can serum albumin level affect the pharmacological action of tolvaptan in patients with liver cirrhosis? A post hoc analysis of previous clinical trials in Japan.

BACKGROUND: Patients with hypoalbuminemia often fail to respond to increased doses of loop diuretics. We therefore performed a post hoc analysis to investigate the pharmacological action of tolvaptan and whether it is dependent on the serum albumin level. METHODS: This analysis was based on four previous clinical trials of tolvaptan in patients with liver cirrhosis who exhibited insufficient response to conventional diuretics. We analyzed the correlation between the change in the initial 24-h cumulative urine volume from baseline and the serum albumin level at baseline, and assessed potential predictive factors of response to tolvaptan. RESULTS: The correlation coefficient was 0.029 in the placebo group and -0.112 in the 7.5 mg tolvaptan group of patients with liver cirrhosis. Administration of tolvaptan provoked a stable response regardless of the serum albumin level. Tolvaptan use was identified as a significant predictor of pharmacological action, and was shown to change the initial urine volume by 885 mL (P < 0.0001) in liver cirrhosis patients. CONCLUSIONS: In this post hoc analysis, tolvaptan increased the initial urine volume from baseline regardless of serum albumin levels. Use of tolvaptan as an add-on therapy to loop diuretics can be considered an optimal therapeutic option in patients with insufficient response to loop diuretics.

Screening for novel antituberculosis agents that are effective against multidrug resistant tuberculosis.

The challenges in preventing and controlling tuberculosis are further complicated by the deadly rise of multi-drug-resistant tuberculosis (MDR-TB). Recognizing the seriousness of the situation, we initiated a program to screen new agents that would satisfy these unmet needs and have a favorable safety profile. Mycobacteria are well known for their lipid-rich properties. In Mycobacterium tuberculosis, mycolic acid in particular has been established the wall component related to the pathogenesis in the host. There are approximately 250 identified genes related to biosynthesis of the lipid turnover that contain InhA, the main target of isoniazid. Thus, the logical approach for developing a chemotherapy agent against tubercle bacilli included screening compounds that could inhibit the biosyntheses of mycolic acid and that had a novel chemical structure to ensure improved efficacy against MDR-TB. Some of the screening systems established for those purposes and some of the candidates are outlined.

Synthesis and antituberculosis activity of a novel series of optically active 6-nitro-2,3-dihydroimidazo[2,1-b]oxazoles.

In an effort to develop potent new antituberculosis agents that would be effective against both drug-susceptible and drug-resistant strains of Mycobacterium tuberculosis, we prepared a novel series of optically active 6-nitro-2,3-dihydroimidazo[2,1-b]oxazoles substituted at the 2-position with various phenoxymethyl groups and a methyl group and investigated the in vitro and in vivo activity of these compounds. Several of these derivatives showed potent in vitro and in vivo activity, and compound 19 (OPC-67683) in particular displayed excellent in vitro activity against both drug-susceptible and drug-resistant strains of M. tuberculosis H37Rv (MIC = 0.006 microg/mL) and dose-dependent and significant in vivo efficacy at lower oral doses than rifampicin in mouse models infected with M. tuberculosis Kurono. The synthesis and structure-activity relationships of these new compounds are presented.

OPC-67683, a nitro-dihydro-imidazooxazole derivative with promising action against tuberculosis in vitro and in mice.

BACKGROUND: Tuberculosis (TB) is still a leading cause of death worldwide. Almost a third of the world's population is infected with TB bacilli, and each year approximately 8 million people develop active TB and 2 million die as a result. Today's TB treatment, which dates back to the 1970s, is long and burdensome, requiring at least 6 mo of multidrug chemotherapy. The situation is further compounded by the emergence of multidrug-resistant TB (MDR-TB) and by the infection's lethal synergy with HIV/AIDS. Global health and philanthropic organizations are now pleading for new drug interventions that can address these unmet needs in TB treatment. METHODS AND FINDINGS: Here we report OPC-67683, a nitro-dihydro-imidazooxazole derivative that was screened to help combat the unmet needs in TB treatment. The compound is a mycolic acid biosynthesis inhibitor found to be free of mutagenicity and to possess highly potent activity against TB, including MDR-TB, as shown by its exceptionally low minimum inhibitory concentration (MIC) range of 0.006-0.024 microg/ml in vitro and highly effective therapeutic activity at low doses in vivo. Additionally, the results of the post-antibiotic effect of OPC-67683 on intracellular Mycobacterium tuberculosis showed the agent to be highly and dose-dependently active also against intracellular M. tuberculosis H37Rv after a 4-h pulsed exposure, and this activity at a concentration of 0.1 microg/ml was similar to that of the first-line drug rifampicin (RFP) at a concentration of 3 microg/ml. The combination of OPC-67683 with RFP and pyrazinamide (PZA) exhibited a remarkably quicker eradication (by at least 2 mo) of viable TB bacilli in the lung in comparison with the standard regimen consisting of RFP, isoniazid (INH), ethambutol (EB), and PZA. Furthermore, OPC-67683 was not affected by nor did it affect the activity of liver microsome enzymes, suggesting the possibility for OPC-67683 to be used in combination with drugs, including anti-retrovirals, that induce or are metabolized by cytochrome P450 enzymes. CONCLUSIONS: We concluded that based on these properties OPC-67683 has the potential to be used as a TB drug to help combat the unmet needs in TB treatment.