In move to further fatten its R&D pipeline and strengthen its commitment to rare diseases, Pfizer is buying access to Opko Health’s investigational long-acting human growth hormone for up to $570 million.

hGH-CTP, which is currently being tested for growth hormone deficiency in Phase II (children) and Phase III (adults), could offer a huge benefit to patients as it comes with once-weekly instead of once-daily injections. Alleviating the burden of daily infections could, the firms argue, improve compliance and treatment outcomes.

Pfizer is shelling out $295 million upfront and up to an extra $275 million on achievement of regulatory milestones for an exclusive global license to hGH-CTP, and will also dish out royalty and/or profit sharing payments should the product make it to market.

Opko will lead the clinical activities and will be responsible for funding the development programs for the key indications, while Pfizer will be responsible for all development costs for additional indications as well as all post-marketing studies. The drug giant will also fund commercialisation activities for all indications and lead the manufacturing activities covered by the global development plan.

Explaining its interest in the deal, Pfizer said the global growth hormone market is currently valued at more than $3 billion, and it believes hGH-CTP “has the potential to be the best in class long-acting growth hormone product”.