Wednesday, February 23, 2011

Chance of FDA Approval

Long ago, one of my first blog postings described the "research funnel".  How a drug went from animal tests through three phases of clinical trials and was eventually approved (and how drugs could fail at each step in the process).  If you haven't read that posting, it contains a lot of useful background information on how drugs get approved in the USA:

I used the best data I could find for that post, but I'm very happy to say that Biotechnology Industry Organization (an industry trade group) and BioMedTracker (a company which collects data on drugs in development) have published some much better data on success rates for US FDA approvals.  Their data set is much larger than what I had back then.  And it is interesting! At least to me :-)

The study was conducted from 2004 through 2010 reviewed more than 4,000 drugs from companies large and small and both publicly traded and private.  But NOT university or non-profit research.

Major findings about the process right now:
  • The overall success rate (all the way through successful FDA approval) for drugs moving from early stage Phase I clinical trials is about 9%.  For phase-II it is 15%, for phase-III it is 44%.
  • 63% of drugs in Phase I testing advanced to Phase II
  • 33% of Phase II drugs made it to Phase III
  • 55% of the drugs that made it to Phase III testing filed for approval applications.
  • 80% of the drugs that filed for approval gained eventual approval (only about half were approved on their initial FDA review)
  • Biologics had a 15% chance of going from Phase I through to FDA approval, compared with a 7% success rate for traditional small molecule chemical drugs. A biologic is more complex than a simple drug.  It is generally something derived from a living organism.  For example, a purified microorganism or specially treated or processed blood or tissue would be a biologic.  BCG, cord blood, and ATG are biologics that are being tested on type-1 diabetics.  
  • The highest overall success rate from Phase 1 through likelihood of approval was for infectious diseases, such as hepatitis and HIV drugs, at 12%.  Next was endocrine system drugs, featuring [type-2] diabetes treatments, at 10.4%.  And then autoimmune diseases, such as rheumatoid arthritis, at 9.4%.
  • Overall success rates from Phase I to FDA approval is nearly 9%. This number is comprised of lead and secondary indications. When separated, lead indications have close to a one in seven rate of approval and secondary indications have a rate of one in 30.  This was seen in all phases of clinical development as well as in all disease areas. 
  • The study also shows that large molecule drugs are twice as successful in gaining approval than small molecule drugs.
Major findings about changes in the process:
  • Overall success rate for drugs moving from early stage Phase I clinical trials to FDA approval is about 9%, down from one in five to one in six seen in reports involving earlier years.
  • The 80% approval rate (for drugs that submitted applications), is down from 93% seen in early studies.

Here are some very rough calculations:
There are currently about 15 phase-I trials with a 9% chance of eventual approval   (1.35 total)
There are currently about 10 phase-II trials with a 15% chance of eventual approval (1.50 total)
There are currently about 3 phase-III trials with a 44% chance of eventual approval (1.35 total)
So, a reasonable estimate is that out of the current crop,  4 drugs will eventually be approved.  It will be very interesting to see how this plays out over the next few years.

But with two serious limitations:

First, The study above only included commercial company's drugs.  it did not include drugs being researched at universities.  I would assume that university research is far less likely to eventually be approved than commercial research. (There are at least two reasons for this: first, universities should be more experimental and less worried about practicle applications, and second, they don't have the resources to push treatments and commercial companies do.)  Since several of the current clinical trials are university research, they are less likely to end up being approved.

Second, most of the current crop of treatments in clinical trials are not cures.  Indeed, only one (Burt) has kept people free of external insulin for 4 years.  That is a phase-I trial, so I think it is reasonable that we are going to need about 10 more treatments in phase-I that actually cure people (or get close) before such a cure will become generally available.

I know that many people want to spend a lot of time and resources investigating drugs that are already approved, for some other purpose, in the hopes that they will cure type-1.  This study shows the dangers of such a focus, since those are the secondary indications that have the much lower success rate.  It turns out that most treatments only work on one thing, so if you try to use them for something else, you chance of success goes way down.  (Even if it is cheaper and quicker.)

Also, it is interesting to me that more complex treatments have higher chances of eventual approval.  Biologics are more complex than drugs, but have a greater chance of approval.  More complex molecules are more likely to be approved than simple ones.  My guess is that because these are more expensive to develop, companies only push the very best of them.  Or maybe all the simple cures have already been productized, and only the more complex ones remain.

If you work in the pharma industry, or if it is important to you, I strongly suggest that you look at this PDF file.  It is thick with information:
News reports:;_ylt=AgsEciuYx.Hb5aUFo.oOX0gPLBIF;_ylu=X3oDMTJ2OGI2aGpzBGFzc2V0A25tLzIwMTEwMjE0L3VzX3BoYXJtYWNldXRpY2Fsc19zdWNjZXNzBHBvcwM4BHNlYwN5bl9hcnRpY2xlX3N1bW1hcnlfbGlzdARzbGsDc3VjY2Vzc3JhdGVz

Joshua Levy
All the views expressed here are those of Joshua Levy, and nothing here is official JDRF or JDCA news, views, policies or opinions. 
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