Pfizer Via Facebook

Source: Pfizer via Facebook.

In a bid to protect sales for its human growth hormone drug Genotropin, Pfizer (NYSE:PFE) licensed rights to a longer-lasting human growth hormone therapy, hGH-CTP, in December. This longer-lasting drug has just completed enrollment in a key phase 3 trial that could clear the way for a potential FDA filing next year.

Reimagining care
Because human growth hormone deficiency can slow or halt the body's ability to grow, human growth hormone is used to treat tens of thousands of children and adults who don't adequately produce enough of the hormone naturally. Typically, patients with human growth hormone deficiency are identified by the time they are between two and three years old. However, while most people are born with human growth hormone deficiency, it can also be caused by other medical conditions or injuries.

Currently, a host of companies, including Pfizer, market therapies that are injected daily to make up for the deficiency, and often this treatment continues throughout a patient's lifetime. Because of the daily injection schedule and the chronic nature of this condition, companies like Pfizer are working on therapies to ease patient burden.

In Pfizer's case, hGH-CTP, which was licensed from Opko Health, could revolutionize patient treatment by reducing injections to once per week. Currently, hGH-CTP is in phase 3 trials for use in adults, and phase 2 trials for use in children.

Pfizer Via Facebook

Source: Pfizer via Facebook.

A billion dollar market opportunity
Pfizer's Genotropin is one of the most widely-used human growth therapies, but a host of other companies, including market-share leader Novo Nordisk, also market treatments.

Last year, Pfizer's sales of Genotropin totaled $723 million, and in the first quarter, Genotropin revenue was $138 million. Meanwhile, over at Novo Nordisk, sales of its Norditropin totaled $973 million in 2014, and $274 million in the first quarter at current exchange rates. The ability to protect Genotropin revenue and conceivably win away share from others like Novo Nordisk suggests that Pfizer's deal to license Opko Health's hGH-CTP may prove to be savvy.

Pfizer paid Opko Health $295 million up front, and agreed to pay up to an additional $275 million in milestones, as well as royalties, on any eventual global sales, to get rights to hGH-CTP. Additionally, if hGH-CTP is effective in children, Pfizer will split any eventual profit from both hGH-CTP and Genotropin with Opko Health.

Looking forward
Now that enrollment in the adult study of hGH-CTP is complete, all eyes turn to 2016, when phase 3 trial results are expected to be released in the second half of the year. If those results are positive, then a regulatory filing could follow shortly thereafter.

If so, then Pfizer could be in a position to unleash its Genotropin marketing team to begin pitching hGH-CTP at some point in 2017. Granted, that timeline means that any benefit of hGH-CTP to Pfizer and Opko Health's bottom line is still a ways off, but given that hGH-CTP could mark the biggest advance in treating human growth hormone deficiency in decades, it's worth keeping an eye on.

Todd Campbell has no position in any stocks mentioned. Todd owns the equity research firm E.B. Capital Markets, LLC. E.B. Capital's clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.