FDA Approves Difamilast as New Topical PDE4 Inhibitor for Atopic Dermatitis

The FDA approved difamilast (Adquey; Aurobindo Pharma), a topical phosphodiesterase 4 (PDE4) inhibitor, for the treatment of mild to moderate atopic dermatitis (AD) in patients 2 years and older.¹ The February 2026 approval adds a new nonsteroidal treatment option to the topical armamentarium for AD, offering an alternative for patients who are intolerant to or inadequately controlled with existing therapies, including topical corticosteroids and other PDE4 inhibitors such as crisaborole (Eucrisa; Pfizer) and roflumilast (Zoryve; Arcutis Biotherapeutics).²

Mechanism of Action

Difamilast selectively inhibits PDE4, an enzyme that degrades cyclic adenosine monophosphate (cAMP) within immune cells. Elevated intracellular cAMP suppresses the release of proinflammatory cytokines—including IL-4, IL-13, IL-31, and tumor necrosis factor-α—that are central to AD pathophysiology.¹ This targeted mechanism avoids the skin atrophy and hypothalamic-pituitary-adrenal axis suppression associated with long-term topical corticosteroid use and the immunogenicity concerns associated with biologic therapies.

Efficacy and Safety

The FDA approval was supported by phase 3 clinical trial data in adult and pediatric patients with mild to moderate AD.¹ Patients applying difamilast ointment twice daily achieved statistically significant improvements in Investigator’s Global Assessment (IGA) scores—the primary end point—vs vehicle at week 4, with a meaningful proportion achieving IGA 0 (clear) or 1 (almost clear) with at least a 2-grade improvement from baseline. Secondary end points, including Eczema Area and Severity Index scores and patient-reported pruritus, also favored difamilast, with itch reductions observed early in treatment.²

Difamilast was generally well tolerated. Application site reactions—including mild burning, stinging, and pruritus—were the most common treatment-emergent adverse effects, occurring at lower rates than historically observed with crisaborole.¹ No boxed warning is required, systemic adverse effects were infrequent, and no clinically meaningful laboratory abnormalities were identified, supporting its use as a long-term maintenance option.

Pharmacist Considerations

Pharmacists should counsel patients to apply difamilast twice daily to affected areas, avoiding the eyes and mucous membranes.¹ As difamilast enters a crowded nonsteroidal topical market, pharmacists should be prepared to address comparisons with crisaborole and roflumilast. Roflumilast 0.15% cream is approved for patients 6 years and older with once-daily dosing; difamilast and crisaborole are both approved in patients 2 years and older with twice-daily application. Formulary placement and payer coverage will likely drive dispensing patterns, and pharmacists should monitor for manufacturer co-pay assistance programs and prior authorization requirements at launch.²

Adherence counseling is essential, as patients should understand that consistent twice-daily application is needed to achieve and sustain therapeutic benefit. Pharmacists should also reinforce that emollient use remains a cornerstone of AD management regardless of the pharmacologic agent prescribed. Aurobindo Pharma has indicated plans for a US commercial launch of Adquey following approval.¹

Conclusion

The approval of difamilast reflects the continued expansion of nonsteroidal topical therapies for AD, a disease affecting an estimated 9.6 million children and 16.5 million adults in the US. The availability of multiple PDE4 inhibitors with distinct formulations and age indications provides prescribers and pharmacists with greater flexibility in tailoring treatment to individual patient characteristics­­—including age, affected body surface area, skin type, and prior treatment history.^1,2

REFERENCES

1. Acrotech Biopharma Inc. announces FDA approval of Adquey (difamilast 1%) ointment for the treatment of mild-to-moderate atopic dermatitis. News release. Acrotech Biopharma. February 13, 2026. Accessed February 18, 2026. https://www.aurobindo.com/api/uploads/corporateannouncements/Adquey-(Difamilast)_NDA%20Approval_PressRelease_13-Feb-26.pdf

2. Bankhead C. New topical PDE4 inhibitor gets FDA green light for chronic skin disease. MedPage Today. February 17, 2026. Accessed February 18, 2026. https://www.medpagetoday.com/dermatology/atopy/119913