Anacor Pharmaceuticals is a biopharmaceutical company focused on discovering, developing and commercializing novel small-molecule therapeutics derived from its boron chemistry platform. It is based in Palo Alto, California, United States. Anacor was founded in 2002 based on technology created by Lucy Shapiro at Stanford University and Stephen Benkovic at Pennsylvania State University. Cofounder David Perry served as CEO and President from 2002 to 2014, and took the company public in 2010. Since then, the company has generated a pipeline of both topical and systemic boron-based compounds of which five are currently in clinical development.

In May 2016, Pfizer announced it would acquire Anacor Pharmaceuticals for $5.2 billion, expanding the company's portfolio in both inflammation and immunology drugs areas.

Boron is a naturally occurring element in the environment, but relative to carbon, hydrogen, nitrogen and oxygen, little research has been done on the role of boron in therapeutics because of the limited understanding of the physical properties necessary to provide boron-based compounds with the attributes required of pharmaceutical therapies as well as difficulty in chemical synthesis. However, boron has two qualities that give it advantages in the small-molecule drug discovery process. First, boron has a unique geometry that allows compounds made from it to have two distinct shapes, giving boron-based drugs the ability to interact with biological targets in novel ways and to address targets not amenable to intervention by traditional carbon-based compounds. And second, boron's enhanced reactivity as compared to carbon allows the molecules to hit targets that are difficult to inhibit with carbon chemistry.

Tavaborole is a topical antifungal drug for the treatment of onychomycosis, a fungal infection of the nail and nail bed. Anacor began its Phase 3 trials in December 2010. Tavaborole inhibits an essential fungal enzyme, leucyl-transfer RNA synthetase, or LeuRS, required for protein synthesis. The inhibition of protein synthesis leads to termination of cell growth and cell death, eliminating the fungal infection. No treatment-related systemic side effects have been observed in any of its clinical trials. It gained FDA approval in July 2014.

Crisaborole Topical Ointment 2% is a topical anti-inflammatory product for the treatment of psoriasis and atopic dermatitis. Crisaborole Topical Ointment 2% inhibits PDE4 and reduces the production of TNF-alpha, a precursor of the inflammation associated with psoriasis as well as other cytokines, including IL-12 and IL-23, which are proteins believed to be involved in the inflammation process and immune responses. Crisaborole Topical Ointment 2% is currently in Phase 2b for psoriasis and Phase 3 for atopic dermatitis.