GSK exercises option on Anacor’s novel antibiotic for the treatment of gram-negative infections

GlaxoSmithKline PLC (GSK) and Anacor Pharmaceuticals today announced that GSK has exercised its option to obtain an exclusive licence to develop and commercialise GSK2251052, formerly known as AN3365.

Issued: London, UK

GlaxoSmithKline PLC (GSK) and Anacor Pharmaceuticals today announced that GSK has exercised its option to obtain an exclusive licence to develop and commercialise GSK2251052 (GSK ‘052), formerly known as AN3365. GSK ‘052 is a novel, systemic antibiotic derived from Anacor’s boron chemistry platform.

In early stage studies, GSK ‘052 has shown robust activity against multi-resistant gram-negative bacteria with no cross resistance to existing classes of antibiotics. GSK ‘052 will be developed as a potential treatment for complicated urinary tract infection (cUTI), complicated intra-abdominal infections (cIAIs), and hospital/ventilator-associated pneumonia (HAP/VAP).

Under the terms of the agreement, Anacor will receive an option exercise fee of $15 million and is eligible for further development and commercialisation milestone payments and royalties on any future product sales. GSK will now assume responsibility for further development of the compound and any resulting commercialisation.

“GSK ‘052 has an entirely novel mechanism of action with the potential to be the first new class antibacterial to treat serious hospital gram-negative infections in 30 years,” said David Payne, Vice President of GSK’s Anti-bacterial Drug Discovery Unit. “Our collaboration with Anacor has enabled the rapid progression of GSK ‘052, and we are excited about the opportunity to address the growing need for new treatments for serious hospital acquired infections.”

“The increasing prevalence of gram-negative strains of bacteria that are resistant to current antibiotics has created a significant unmet medical need that GSK ‘052 appears well positioned to address,” said David Perry, Chief Executive Officer of Anacor. “GSK has been an excellent development partner and we are confident that their continued commitment will help ensure that this important compound can reach its fullest potential.”

About GSK ‘052

GSK ‘052 is a novel boron-based, small-molecule candidate that targets the bacterial enzyme leucyl tRNA synthetase. Preclinical studies suggest that GSK ‘052 is a promising compound for the treatment of infections caused by a broad range of gram-negative bacteria, including E. coli, K. pneumoniae, Citrobacter spp, S.marcescens, P.vulgaris, Providentia spp, Pseudomonas aeruginosa and Enterobacter spp. GSK ‘052 has demonstrated a potent effect on strains harbouring known resistance to widely-used antibiotics.

About the GSK and Anacor Alliance

In October 2007, GSK and Anacor entered into a worldwide strategic alliance for the discovery, development and commercialisation of novel medicines for viral and bacterial diseases. The collaboration provides GSK access to Anacor's proprietary boron-based chemistry for use in four target-based project areas. Under the terms of the agreement with GSK, Anacor retains responsibility for the development of compounds through to clinical proof of concept, at which point GSK has an exclusive option to license each compound for further development and commercialization on a worldwide basis. Contingent on achieving certain milestones, Anacor is eligible to receive development and regulatory milestone payments up to $84 million as well as commercial milestones and tiered double-digit royalties up to the mid-teens, which are dependent on sales achieved.

GlaxoSmithKline – one of the world’s leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For further information please visit

Anacor Pharmaceuticals

Anacor is a biopharmaceutical company focused on discovering, developing and commercializing novel small-molecule therapeutics derived from its boron chemistry platform. Anacor has discovered and is developing four additional clinical compounds, including its other two lead programs: AN2690, a topical antifungal for the treatment of onychomycosis and AN2728, a topical anti-inflammatory PDE-4 inhibitor for the treatment of psoriasis. The Company is developing other systemic antibacterial therapeutics under a research and development agreement with GlaxoSmithKline. For more information visit

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