Thursday, February 23, 2012

Xcovery blog revisited (state of targeted Rx)

About five years ago I started a blog dedicated to targeted therapeutics, especially kinases inhibitors. The blog was an outgrowth of Xcovery, the kinase discovery spin-out from the Scripps Research Institute that I started and served as EVP of Business Development. 

I was already tracking developments in biopharm so the blog was an outlet for some of basic analysis and a fun way to share my opinion and connect with others in the industry. 

One of the regular bits of analysis was tracking the performance of FDA approved targeted drugs. Just for fun, here's a five year update, with some analysis:


Of note:

  • The 17 approved molecularly targeted drugs accounted for $27B in global sales in 2011. Think about that for a second, then consider that most of these drugs have been on the market for only 5-6 years, and their approved indications are still growing. Consider too that most have not been applied as combination therapies.
  • Even the senior citizen of the group (Herceptin, approved in 1998), has seen prolonged growth, averaging 36% per year over the last five years.
  • With 8 blockbusters and several more close and still growing (Tasigna, Sprycel, etc), almost all of the targeted drugs are either blockbusters, or well on their way. So much for the concern that targeting drugs might limit the market potential.
  • The top 4 (Avastin, Herceptin, Gleevec, and Lucentis) have made a mockery of their projected sales ceilings and are still growing strongly.
  • On the other hand, the only assets that appear to be underperforming expectations are Amgen’s Vectibix, GSK’s Tykerb, and Pfizer’s Torisel (specific sales data isn’t available for 2011, as Torisel is listed under “other oncology,” totaling ~$130M across several drugs.)
  • Vectibix is still playing catch up to Erbitux, and Tykerb hasn’t gained much traction against the Roche juggernaut.
  • I wonder what Amgen’s new CEO will do about Vectibix. It seems that there’s 2 choices: go big (invest in expanding trials for more indications and in comparison with Erbitux) or go home (sell the product to another biopharm.)
  • 4 of the top 6 are Roche drugs, which means that they were discovered by Genentech. Hats off again to the DNA team in South San Francisco for their amazing science and productivity. I wonder if we will ever see any other drug discovery effort be so inventive and productive for a prolonged period.
  • Also: I don’t think anyone is doubting the wisdom of Roche buying the piece of DNA that Roche didn’t own. I haven’t run the numbers, but I’d be shocked if the DNA acquisition wasn’t a resounding financial win for Roche.
  • Unfortunately, OSI’s acquisition of Macugen was a tremendous dud.
  • I am encouraged by the progress since my last analysis in 2006 – an average of two new approvals each year, with most new products addressing new targets or diseases, in contrast to the incremental “me too-ism” in other pharma areas like ED or cholesterol drugs.
A few sweeping generalizations:
  • FDA approval and sales success seem to be connected to corporate resources. Small to mid-cap biotechs have been chasing targeted therapies for ~15 years without much output. (I’m talking about companies such as Exelixis, Vertex (pre-HepC), Ariad, etc., though I don’t mean to pick on specific companies.) With three exceptions (Onyx’s Nexavar, OSI’s Tarceva, and the former ImClone’s Erbitux), the targeted therapies have largely been developed in-house by “old” companies with multi-billion dollar market caps and the resources to match. (You could make the case that Amgen’s Vectibix came from a small targeted effort at Abgenix, but I suspect that it was Amgen’s resources that got Vectibix through FDA approval. Similarly, Sutent started at Sugen, but Pharmacia and Pfizer seemed to have provided the big push.)
  • A gross generalization: the small to mid-caps tend to lack broad biological or disease-specific expertise, instead investing in target-specific expertise, or platform-specific expertise, thinking that broad expertise (ancillary to their target or disease of interest) is expensive overhead. I wonder if the results to date argue for the big pharma discovery model, or just reinforces the need for a broad portfolio to be successful in drug discovery and development.
  • With rare exception (as in Pfizer’s Xalkori and Novartis’ Gleevec), the path to FDA approval has been arduous for these drugs. There are a number of targeted drug developers who hold out hope that their P2 or P3 results will be so clear and strong that their clinical trials will be stopped early and approved quickly. That’s definitely the exception, unfortunately, and even in the positive trials for targeted drugs, the data has tended to be good, not great. I suspect that is a function of the requirements of clinical trial design and comparison to first-line chemotherapies. As a result the “new” drugs are posting smallish survival benefits when compared to the “old” therapies, with no accounting for how certain patient segments have had dramatic benefits. (Thus starting the vicious circular argument that targeted therapies ought to have stratified patient populations in clinical trials, but stratifying patients shrinks the market potential for such drugs, bring the business viability of the targeted therapy into question.) It seems that the FDA could take the Xalkori experience and develop a novel process for rapid approval based on patient stratification without derailing or obviating more broad approval for the drug.
The $27B in revenue in this segment (likely to grow past $50B in 2014) has hopefully served to further de-risk pharma R&D in molecularly targeted therapeutics. Coupled with advancements in medicinal chemistry, we will hopefully see more and better targeted therapies in the future. 

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