Apogee’s Zumilokibart Advances Toward Phase 3 After Positive Phase 2 Atopic Dermatitis Results

Apogee Therapeutics announced positive 16-week results from Part B of its Phase 2 APEX clinical trial evaluating zumilokibart in patients with moderate-to-severe atopic dermatitis (AD), with the company planning to advance the therapy into Phase 3 development in the second half of 2026.¹

According to the company, the investigational anti-IL-13 monoclonal antibody met all primary and secondary endpoints with high statistical significance, while also demonstrating a safety profile generally consistent with other therapies in the class.¹ Interleukin-13 has been identified as a key cytokine involved in type 2 inflammation and skin barrier dysfunction associated with AD pathogenesis.²

Could zumilokibart offer less frequent dosing in atopic dermatitis?

The randomized, placebo-controlled APEX Part B trial enrolled 346 adult patients who received either high-, mid-, or low-dose zumilokibart or placebo. The primary endpoint evaluated the proportion of patients achieving at least a 75% reduction in Eczema Area and Severity Index scores (EASI-75) at Week 16.¹

Results showed that 65.9% of patients receiving the mid-dose regimen achieved EASI-75 at Week 16 compared with 23.4% in the placebo arm. High-dose treatment produced a 61.6% EASI-75 response rate, while the low-dose arm achieved 50.5%.¹

The mid-dose regimen also met several key secondary endpoints, including:

• 46.0% of patients achieving Investigator’s Global Assessment (IGA) 0/1 responses versus 10.9% for placebo
• 47.4% achieving EASI-90 responses compared with 9.3% for placebo
• 50.5% achieving at least a four-point reduction in itch Numeric Rating Scale scores compared with 13.9% in placebo-treated patients
• 20.6% achieving very low disease activity versus 4.5% for placebo¹

“We are thrilled by the strength and consistency that zumilokibart demonstrated across all endpoints from today’s APEX Part B induction results, which we believe could set a new standard of care for patients,” said Michael Henderson, chief executive officer of Apogee, in a company press release.¹

The company stated that the mid-dose regimen demonstrated the strongest balance of efficacy and tolerability and is expected to advance into Phase 3 trials pending regulatory discussions.¹

Investigators also highlighted the therapy’s dosing profile. According to Apogee, patients received four dosing days during the induction period compared with approximately nine dosing days associated with current standard-of-care biologic regimens.¹ Current biologic therapies for moderate-to-severe AD often require dosing every two to four weeks, creating adherence and treatment burden challenges for some patients.³

“Patients with atopic dermatitis and their physicians want therapies that provide durable and deeper disease control with less frequent dosing,” said Ruth Ann Vleugels, director of the Atopic Dermatitis Program at Mass General Brigham and professor of dermatology at Harvard Medical School, in the release.¹

The safety profile observed in the study was generally consistent with other agents targeting IL-13, according to the company. The most common treatment-emergent adverse events included nasopharyngitis, headache, and noninfective conjunctivitis. For the planned Phase 3 mid-dose regimen, pooled conjunctivitis rates were 10.6%, compared with 15.1% in the low-dose arm and 20.7% in the high-dose arm.¹

How is apogee expanding zumilokibart beyond atopic dermatitis?

Apogee said the results further support the therapy’s “pipeline-in-a-product” potential across multiple inflammatory and immunology indications.¹

In addition to planned Phase 3 AD studies, the company announced development plans for eosinophilic esophagitis (EoE) and asthma. The ELEVATE Phase 2a trial in EoE is expected to begin in the second half of 2026, while the ASPIRE Phase 2b asthma trial is expected to initiate during the first half of 2027.¹ IL-13 inhibition has previously demonstrated therapeutic relevance across multiple type 2 inflammatory diseases, including asthma and eosinophilic gastrointestinal disorders.²

The company also announced a strategic financing collaboration with Blackstone Life Sciences that is expected to support development and commercialization activities for zumilokibart across AD, asthma, and EoE indications.¹

References

1. Apogee Therapeutics Announces Positive 16-Week Part B Induction Dose Optimization Results from Phase 2 APEX Trial of Zumilokibart in Moderate-to-Severe Atopic Dermatitis. (2026 May 27). Apogee Therapeutics. https://investors.apogeetherapeutics.com/news-releases/news-release-details/apogee-therapeutics-announces-positive-16-week-part-b-induction
2. Guttman-Yassky, E., Waldman, A., Ahluwalia, J., Ong, P. Y., & Eichenfield, L. F. (2017 Sep). Atopic dermatitis: pathogenesis. Seminars in cutaneous medicine and surgery. https://doi.org/10.12788/j.sder.2017.036
3. Simpson EL, et al. (2016 Dec 15). Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis. N Engl J Med. https://www.nejm.org/doi/full/10.1056/NEJMoa1610020