Could These Experimental Drugs Eclipse Harvoni's Historic Launch?

Relatively few drugs attain the esteemed blockbuster status of $1 billion in annual sales. For those that do, many of them take several years to reach that mark. Gilead Sciences , however, raised the bar with the launch of hepatitis C drug Harvoni. In just its first three months on the market, Harvoni generated revenue topping $2.1 billion.

We asked three of our biotech analysts which experimental drugs they think might have the best shot at doing even better than Harvoni. Here's what they had to say.

: If any drug is going to be able to beat Harvoni's launch, it will probably have the same characteristics as Harvoni. That is:

  • Be a cure (which allows for a higher price than drugs for a chronic condition).
  • Treat a disease with an unmet medical need (it's hard to launch fast with competition).
  • Have enough patients with the disease (it's hard to launch quickly in an orphan indication).

Assuming the treatment is eventually approved,bluebird bio has the first two characteristics with its LentiGlobin BB305 drug product for sickle cell disease. The estimated 90,000 to 100,000 Americans with sickle cell disease is substantially less than the 3.2 million Americans with hepatitis C, but because we're talking about launch versus total sales, there are probably enough patients to ramp up sales quickly given the unmet need for sickle cell patients.

A couple of caveats are needed here, though. Bluebird is testing LentiGlobin BB305 in an orphan indication called beta-thalassemia that only affects about 15,000 patients in the U.S. and Europe. If the treatment is approved for that disease first, and we're starting the comparison-clock with Harvoni at that point, it might have trouble matching sales right off the bat, given the smaller patient population.

Also, like Harvoni, price is going to be an issue. LentiGlobin BB305 is much more expensive to manufacture than Harvoni, so it will likely be priced much higher. If bluebird has trouble getting insurers to sign on to its high price, it will mute the launch.

Finally, the launch could be limited by the manufacturing of LentiGlobin BB305. The treatment is patient specific, first requiring the removal of patients' hematopoietic stem cells, then gene therapy on those cells to insert the functioning gene, and finally, an autologousstem cell transplantation to put the cells back in the patients. Depending on bluebird's manufacturing capabilities when it's approved, the launch could be limited by the number of patients that bluebird can treat rather than the number of patients that are actually prescribed the treatment.

Those caveats aside, however, I see promising potential in this drug to surpass the incredible ramp-up of Harvoni if approved.

Keith Speights:Biogen rocked the biotech world recently with its announcement of results from an early stage clinical study of aducanumab in treating patients with Alzheimer's disease. The drug demonstrated a statistically significant slowing of cognitive decline and reduction of amyloid plaque, which is prevalent in the brains of patients with Alzheimer's disease.

Why could aducanumab potentially outshine mighty Harvoni? Two of the criteria mentioned by Brian make the case. First, to say that Alzheimer's is a disease with an unmet medical need is an understatement. There is no approved treatment proven to be effective at treating this horrifying disease. Second, the number of people with Alzheimer's disease is huge -- around 25 million worldwide. With the populations aging in many countries, including the U.S., this number appears likely to grow even more.

Granted, aducanumab is not a cure for Alzheimer's disease. However, the enormity of the need, combined with the magnitude of patients, prompted Leerink Partners analysts to project peak annual sales of $14.5 billion. If they're right, it probably won't take the drug very long to hit that level.

Biogen plans to skip straight to phase 3 testing with its promising Alzheimer's drug, but it's still early. A lot could happen to derail the drug. On the other hand, we could be wondering in just a few years what drug could possibly eclipse the launch of aducanumab.

Todd Campbell:Harvoni targets a pretty big population, but there's arguably no bigger market in terms of patient population than the market for heart-disease medications like statins.According toExpress Scripts, high cholesterol (a key risk factor of heart disease) affects as many as 71 million people in the United States alone.

As a result, some of the planet's best-selling drugs have been cholesterol-busting medications, such asPfizer'sLipitor. Prior to losing patent protection in 2011, Lipitor was racking up sales of $12 billion per year.With jaw-dropping sales like that, it's not a stretch to think that the launch ofAmgen's bad-cholesterol-fighting drug Repatha could result in a Harvoni-like sales launch.

The FDA is slated to make a decision on whether or not to approve Repatha in August. If it gives Amgen the green light, the drug will initially be approved for use in patients that don't respond to, or whose bad cholesterol is inadequately controlled by, statins. Since Express Scripts thinks Repatha could have a price tag of $10,000 per year, and Repatha could be used in hundreds of thousands of patients out of the gate, this drug could have a shot at eclipsing Harvoni.

The article Could These Experimental Drugs Eclipse Harvoni's Historic Launch? originally appeared on

Brian Orelli has no position in any stocks mentioned. Keith Speights owns shares of Express Scripts and Gilead Sciences. Todd Campbell owns shares of Gilead Sciences. The Motley Fool recommends Bluebird Bio, Express Scripts, and Gilead Sciences. The Motley Fool owns shares of Express Scripts and Gilead Sciences. 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.

Copyright 1995 - 2015 The Motley Fool, LLC. All rights reserved. The Motley Fool has a disclosure policy.