Tanabe Pharma Shares Encouraging Phase 3 Data for Dersimelagon in Rare Photodermatoses; Biogen’s Litifilimab Demonstrates Significant Skin Disease Reduction in Phase 2 CLE Trial; Merck’s WINREVAIR Shows Promising Phase 2 Results in CpcPH-HFpEF Population; AstraZeneca’s Tozorakimab Meets Primary Endpoints in OBERON and TITANIA Phase III COPD Trials; Amgen’s REPATHA Shows Strong Cardiovascular Risk Reduction in High-Risk Patients

Tanabe Pharma Reports Positive Phase 3 INSPIRE Results for Dersimelagon in EPP and XLP

Tanabe Pharma Corporation has announced detailed findings from the Phase 3 INSPIRE trial evaluating investigational oral dersimelagon in patients with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP). The results were shared during a late-breaking oral session at the American Academy of Dermatology Annual Meeting 2026 on March 28, 2026.

Dersimelagon, a selective melanocortin 1 receptor (MC1R) agonist, successfully achieved its primary endpoint. It demonstrated a statistically significant increase in the average daily sunlight exposure time before the onset of the first prodromal symptom during Weeks 12–16 compared to placebo, with a placebo-adjusted least-squares mean difference of 23.19 minutes (p=0.004) in the primary analysis. This benefit further improved to 29.64 minutes at Week 16 (p=0.004) in supplementary analysis.

The study also met key secondary endpoints, showing significant improvements in Patient Global Impression of Change (PGIC) scores and a reduction in total pain events versus placebo (PGIC: -1.83, p<0.001; pain reduction: 39%, p=0.004), reinforcing the clinical relevance of the primary outcome.

Dersimelagon has received both U.S. FDA Fast Track and Orphan Drug designations, highlighting the substantial unmet medical need and its potential to deliver meaningful therapeutic benefit. Tanabe Pharma has begun preparations for a rolling submission of its New Drug Application (NDA).

Biogen Reports Second Positive Phase 2 Litifilimab Study in Cutaneous Lupus at 2026 AAD Meeting

Biogen Inc. reported encouraging findings from Part A of the Phase 2 segment of its AMETHYST Phase 2/3 trial evaluating litifilimab in patients with cutaneous lupus erythematosus (CLE). Litifilimab is a first-in-class humanized IgG1 monoclonal antibody designed to target blood dendritic cell antigen 2 (BDCA2), and it may represent the first novel approved treatment for CLE in nearly 70 years.

In Part A of the AMETHYST study, both efficacy and safety were assessed through week 24, demonstrating improvements in skin disease activity across multiple endpoints. These findings align with previously reported positive results from the Phase 2 LILAC study, published in The New England Journal of Medicine.

Data from both the LILAC and AMETHYST trials contributed to litifilimab receiving Breakthrough Therapy Designation from the U.S. FDA. The latest results are currently being presented at the American Academy of Dermatology (AAD) Annual Meeting.

AMETHYST Part A achieved its primary endpoint, with litifilimab showing an 11.8% greater reduction in disease activity versus placebo in individuals with CLE (95% CI: 1.39–22.27; p < 0.05). This was assessed using the CLA-IGA-R erythema score of 0–1 (clear or almost clear) at Week 16, with response rates of 14.7% for litifilimab compared to 2.9% for placebo. Secondary endpoints in Part A were not adjusted for multiplicity; therefore, statistical significance cannot be confirmed.

Treatment with litifilimab led to rapid and sustained improvements in skin disease activity, with separation from placebo evident as early as Week 4 (19.3% vs. 5.5%; Δ=13.8; CI: 1.19–26.46), based on CLASI-50 response. This improvement was maintained through Week 24 (40.8% vs. 21%; Δ=19.8; CI: 1.46–38.15). A higher proportion of patients receiving litifilimab also achieved CLASI-70 responses at Week 24 compared with placebo (21.7% vs. 5.8%). CLASI-50 and CLASI-70 correspond to 50% and 70% improvements from baseline in CLASI-A scores, respectively. Additionally, 16.3% of patients treated with litifilimab reached a CLASI score of 0–3 (indicating minimal or no disease activity) at Week 24, whereas none in the placebo group did (Δ=16.3; CI: 7.07–25.62).

Litifilimab was generally well tolerated in Part A, with a safety profile consistent with prior studies, including the Phase 2 LILAC trial. Over the 24 weeks, adverse events were reported in 74.6% (44/59) of patients in the litifilimab group and 64.7% (22/34) in the placebo group, with most events being mild to moderate. Serious adverse events occurred in 6.8% (4/59) of patients receiving litifilimab and 2.9% (1/34) of those receiving placebo.

Merck’s WINREVAIR Demonstrates Strong Phase 2 Proof-of-Concept in CpcPH and HFpEF Patients

Merck & Co. reported comprehensive findings from the Phase 2 CADENCE trial, which assessed the efficacy, safety, and tolerability of two dosing regimens (0.3 mg/kg and 0.7 mg/kg) of WINREVAIR in adults with combined post- and precapillary pulmonary hypertension alongside heart failure with preserved ejection fraction (CpcPH-HFpEF).

In this specific patient group, WINREVAIR demonstrated a statistically significant and clinically meaningful reduction in pulmonary vascular resistance (PVR) compared with placebo at week 24. The 0.3 mg/kg dose achieved a reduction of 1.02 Wood units (n=54; 95% CI, -1.81 to -0.23; p=0.004), while the 0.7 mg/kg dose showed a 0.75 Wood units decrease (n=55; 95% CI, -1.52 to 0.03; p=0.024).

Key secondary endpoints evaluated included six-minute walk distance (6MWD), echocardiographic parameters, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, and time to clinical worsening (TTCW). These late-breaking results were presented at the American College of Cardiology Annual Scientific Session and Expo 2026, published concurrently in Circulation, and highlighted during an ACC.26 press conference.

In terms of functional outcomes, patients receiving the 0.7 mg/kg dose experienced a 5.8-meter increase in 6MWD, which did not reach statistical significance (95% CI, -17.3 to 28.9). Due to the study’s prespecified hierarchical testing approach, subsequent secondary endpoints were not formally tested; however, patients in the 0.3 mg/kg arm showed a 20.3-meter improvement in 6MWD from baseline (95% CI, 1.5 to 39.1).

AstraZeneca’s Tozorakimab Meets Primary Endpoints in Both Pivotal OBERON and TITANIA Phase III COPD Trials

Top-line findings from the Phase III OBERON and TITANIA studies in chronic obstructive pulmonary disease (COPD) demonstrated that tozorakimab lowered the annual rate of moderate-to-severe exacerbations versus placebo. This benefit was observed both in the primary subgroup of former smokers and in the broader study population, which included current and former smokers across all blood eosinophil levels and varying degrees of lung function impairment. Overall, tozorakimab showed good tolerability and a favourable safety profile.

Tozorakimab is a novel monoclonal antibody targeting interleukin-33 (IL-33), designed to block signalling from both its reduced and oxidised forms. This dual mechanism may help reduce inflammation while interrupting the cycle of mucus dysfunction that drives disease progression in COPD. In the OBERON and TITANIA trials, the therapy was evaluated in patients who continued to experience exacerbations despite receiving standard inhaled treatments. Participants were administered 300 mg of tozorakimab or a placebo every four weeks alongside standard care.

COPD affects nearly 400 million individuals worldwide and remains a progressive, heterogeneous condition as well as the third leading cause of death globally. Despite treatment with inhaled standard therapies, more than half of patients still suffer exacerbations, increasing their risk of cardiopulmonary complications and mortality. Detailed results from the OBERON and TITANIA trials are expected to be presented at an upcoming scientific meeting.

Further Phase III studies of tozorakimab in COPD, PROSPERO and MIRANDA, are currently underway. The drug is also being investigated in a Phase III trial for severe viral lower respiratory tract disease and in a Phase II study for asthma.

Amgen’s REPATHA Demonstrates 31% Reduction in First Major Cardiovascular Events Among High-Risk Patients Without Significant Atherosclerosis

Amgen reported that REPATHA, when used alongside statins or other LDL-C–lowering therapies, significantly lowered the risk of initial major adverse cardiovascular events (MACE) in high-risk primary prevention patients with diabetes who did not have established significant atherosclerosis. These results were shared during a late-breaking session at the American College of Cardiology 75th Annual Scientific Session and were concurrently published in the Journal of the American Medical Association.

The findings stem from a subgroup analysis of 3,655 diabetic patients at elevated cardiovascular risk but without known significant atherosclerosis, followed for a median duration of 4.8 years as part of the Phase 3 VESALIUS-CV trial. The analysis showed that REPATHA reduced the risk of the primary composite endpoint, coronary heart disease (CHD) death, myocardial infarction, or ischemic stroke (3-point MACE), by 31% versus placebo. 

A similar 31% risk reduction was observed for a broader composite endpoint (4-point MACE), which also included ischemia-driven revascularization. Median LDL-C levels at 96 weeks were substantially lower in the REPATHA group (44 mg/dL) compared to the placebo group (105 mg/dL), based on a lipid sub-study involving 548 patients.

Consistent benefits were observed across secondary endpoints, including combinations such as heart attack, ischemic stroke, or revascularization; CHD death, heart attack, or revascularization; and cardiovascular death, heart attack, or ischemic stroke. Individually, REPATHA showed numerical reductions in heart attack risk (31%), ischemia-driven revascularization (34%), and ischemic stroke (33%). Trends toward lower mortality were also seen, including reductions in cardiovascular death (32%), CHD death (27%), and all-cause mortality (24%).

Originally approved in 2015, REPATHA has been prescribed to over 8 million patients worldwide. In August 2025, the U.S. Food and Drug Administration expanded its indication to include adults at elevated risk of major cardiovascular events due to inadequately controlled LDL-C levels.