Pfizer and Anacor Pharmaceuticals have entered into a definitive merger agreement under which Pfizer will acquire Anacor for $99.25 per Anacor share, in cash, for a total transaction value, net of cash, of approximately $5.2 billion.

Anacor’s flagship asset, crisaborole, a differentiated non-steroidal topical PDE4 inhibitor with anti-inflammatory properties, is currently under review by the U.S. FDA for the treatment of mild-to-moderate atopic dermatitis, commonly referred to as eczema.

In both of its Phase 3 pivotal studies, crisaborole achieved statistically significant results on all primary and secondary endpoints and in March 2016, the FDA accepted for review Anacor’s New Drug Application seeking approval of crisaborole for the potential treatment of mild-to-moderate atopic dermatitis in children and adults.