Monday, July 28, 2014

In case you missed it…. Why we fill out prior authorization forms for colchicine….

by Kirsten Bibbins-Domingo, MD, PhD

I recently finished several weeks of outpatient attending and spent a good bit of time filling out prior authorization forms for medications not covered under the formulary of our insurers.  Many of these “prior auths” were for colchicine – or more correctly for the new brand name drug Colcrys.

In case you were busy caring for patients, teaching, studying, or conducting research and thus missed the specifics of why we can no longer get colchicine  - a drug that’s been used for the treatment of gout since the 19th century -  I thought I’d share the highlights of this outrageous story, detailed nicely in this 2010 perspective piece in the NEJM and a piece in Slate magazine in 2011.

Here are the key points:
  •  The FDA believes it important to study safety and efficacy of drugs in current practice that have not previously been subject to rigorous RCTs, generally older drugs like colchicine.  In order to incentivize companies to conduct such trials, the FDA grants them marketing exclusivity.  In this case a company applied to conduct such a trial of colchicine and subsequently was granted 3 years of marketing exclusivity in 2009.  This company markets colchicine as Colcrys
  • Marketing exclusivity means the cost of this medication went from $0.09 per tablet to $4.85 per tablet.  Additionally, as a result of a lawsuit, all generic versions of colchicine had to be pulled from the market.
  •  The maker of Colcrys was granted an additional 7 years because of a separate trial of colchicine for treatment of Mediterranean Fever (more time granted because this disease is covered under the Orphan Drug Act).
  •  State Medicaid programs filled about 100,000 prescriptions of colchicine in 2007 and paid approximately $1 million for the drug.  In the NEJM perspectives piece the new Colcrys was estimated to increase these costs to $50 million annually.

So this leaves me wondering….
  •  Did we learn something important from these new trials of colchicine?  Much of the information on harms of medication comes not from the trials themselves, but from the subsequent planned or ad hoc surveillance of reported adverse reactions to medications.  Given the decades of experience with colchicine, did we really learn something that we didn’t already know about harms?
  •  If the purpose of the trials were to learn more about efficacy, were the trials conducted in a way to give us information that might actually help us clinically, usually information about minimally effective dosing, duration, interaction with other medications?  I can’t find the trial results, but since these questions require more complicated study design, I suspect not.  From the Colcrys website, the recommended prescribing information for prophylaxis of gout flares is 0.6 mg once or twice daily in adults.  Seems surprisingly similar to the way we used to prescribe colchicine.
  •  Even if there was beneficial information generated from these trials, was it really worth the resulting costs?  Fifty-fold rise in Medicaid expenditures, potential medication errors (allopurinol is the routinely recommended lower cost alternative to Colcrys, which substitutes in some, but certainly not all clinical scenarios), lack of access to colchicine for other indicated treatments such as acute pericarditis (my cardiology colleagues say Colcrys was either not approved or not approved within a period compatible with treating this acute condition), and the hassle factor for both patients and providers of this switch are just a few.
  • And even if there is a societal good for determining the safety and efficacy of older medications, would it not make more sense for the FDA to partner with another government agency to pay for this societal good?  Couldn’t these trials have been conducted by the NIH, AHRQ, PCORI, or Medicare at much lower costs, particularly the considerable downstream costs to patients and society?

Frankly this seems outrageous to me.
By the way, the company that makes Colcrys has marketing exclusivity until 2029.

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