Amgen, Inc. (AMGN), Merck & Co., Inc. (MRK): Can It Field a Psoriasis Blockbuster?

Targeting psoriasis, rheumatoid arthritis, and other immune diseases has created some massive markets over the last decade. How massive? The market was sized up at an estimated $72.2 billion in 2010, according to BCC Research — and growth isn’t slowing any time soon. That’s good news for patients, too. The pharmaceutical industry’s fascination with an improved understanding of biologics has led to dozens of drugs that treat the underlying causes of diseases, rather than small molecules of years past that only treated symptoms.

Merck & Co., Inc.

Few companies haven’t joined the rush to develop biologics and novel small molecule classes to treat immune diseases. While some companies got a big head start over the field, next-generation therapies are being developed in pipelines across the industry. Merck & Co., Inc. (NYSE:MRK) is one company looking to capitalize on the trend and will shortly begin phase 3 trials on its leading psoriasis biologic therapy candidate. Going by the catchy pipeline name of MK-3222, the drug has huge potential if it ever receives approval from the Food and Drug Administration, or FDA.

About that competition I mentioned…
Older therapies aren’t exactly losing their grasp on the markets they took by storm just yet. A quick look at 2012 sales data from the first three biologics approved that work by inhibiting the TNF-alpha protein — integral to immune system communication — shows exactly that.

Company Drug 2012 Sales
Johnson & Johnson (NYSE:JNJ) Remicade $6,139 million
Amgen, Inc. (NASDAQ:AMGN) Enbrel $4,236 million
AbbVie Humira $9,265 million

Source: Company 2012 earnings.

Aside from the big three, there are newer therapies on the market and in development that target TNF-alpha indirectly by inhibiting the proteins further upstream in the cellular communication chain. For instance, Johnson & Johnson’s Stelara binds to interleukin 23 and interleukin 12, which regulate TNF-alpha production. The therapy has been approved for psoriasis and is in late stage trials for Crohn’s disease and ankylosing spondylitis.

The biggest advantage for new therapies may lie in dosing schedules. Consider that during a 12-week study comparing Stelara to Enbrel, the TNF-alpha inhibitor was administered twice a week for the length of the study, while the drug candidate was administered just twice over the same period. Stelara still managed to beat Enbrel in high-dose groups with 71% and 49% of patients responding, respectively.

Is it too late for Merck & Co., Inc. (NYSE:MRK)?
The dosing regimen of Stelara raises the bar significantly for all therapies. However, Merck & Co., Inc. (NYSE:MRK)’s MK-3222 has essentially the same requirements; administered twice in the first four weeks of treatment and then once every 12 weeks thereafter. The two therapies work in slightly different ways, too, with MK-3222 targeting a different region of interleukin 23 while sparing interleukin 12. In theory, that could make the drug less destructive to a patient’s immune system, which is the biggest drawback to many immune disease therapies.