Ligand strikes $516m deal to buy Pfenex for expression tech

Ligand Pharmaceutical will buy Pfenex to add the latter’s protein expression technology to its core drug discovery and formulation business.

The deal – worth $516 million – is expected to complete before the end of the year. Ligand cited Pfenex’s expression technology as a major motivation for the deal, pointing out it is out-licensed for numerous commercial and development-stage programs.

CEO John Higgins likened the deal to Ligand’s acquisition of the technology Captisol – gained when the firm bought Cydex in 2011 – and OmniAb, which it added through the takeover of OMT in 2015.

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“The acquisition holds potential to have a significantly positive scientific and financial impact on our business in the short and long term, similar to how our Captisol and OmniAb acquisitions have played out,” he said.

“Pfenex will add an established, proven protein expression platform to Ligand that is highly complementary to our essential, proprietary drug discovery and formulation technologies.”


Pfenex’s expression system uses the P. fluorescens bacterium for large-scale protein production that cannot be made by more traditional host systems.

The expression system is used for Pfenex’s own product candidates – including its commercial product Bonsity (teriparatide).

Pfenex’s partner partner Alvogen launched teriparatide injection in the US in June.

The expression system is also used by companies like Jazz Pharmaceuticals, which is employing it in the development of PF743, a recombinant Erwinia asparaginase, and PF745, a half-life extended recombinant Erwinia asparaginase.

The Serum Institute of India and Merck & Co also use the system to produce CRM197, a diphtheria toxoid carrier protein for use in prophylactic and therapeutic vaccines.

In addition, earlier this month Pfenex announced a new collaboration with Merck to evaluate other proteins to be produced via the Pfenex Expression Technology platform.

CEO Eef Schimmelpennink told analysts on Pfenex’s Q2 call the firm will receive a $2.5 million upfront fee, additional research funding and the potential for a onetime $2.5 million success fee and $95 million in development and sales milestones for up to three products each.

“We are very excited to extend our partnership with Merck and believe it shows the unique capabilities and value of our platform.”