* FDA gives glimpse of biosimilar approval process
* No "one size fits all" approach, FDA says
* Must evaluate "totality of evidence" for biotech copies
* FDA to release final guidance on biosimilars this year
WASHINGTON, Aug 3 (Reuters) - Evaluating generic versions of complex biotechnology medicines will require a new, more rigorous review process, U.S. drug regulators said, in the first glimpse of their thinking on the subject.
Drugmakers, investors and others have been clamoring for more insight into the approval process for cheaper versions of biotech drugs, known as "biosimilars" -- a potentially multibillion dollar market.
In an article in this week's New England Journal of Medicine made public on Wednesday, officials from the U.S. Food and Drug Administration said the approval for biosimilars "will require a new paradigm of sponsor-FDA interactions," involving analysis of much more data than traditional generics.
Unlike conventional chemical-based drug compounds, biotech drugs are derived from living organisms, such as proteins, and often produced using recombinant DNA technologies.
Tiny differences in manufacturing mean biological drugs are impossible to replicate exactly, leaving regulators with the task of deciding just "how similar is similar enough," when looking at copycat versions of already-approved medicines.
"Given the complex nature of biologics, it's unlikely that a 'one size fits all' systematic assessment of biosimilarity can be developed," FDA officials, including the head of its drugs center, Janet Woodcock, said in the article.
Approval guidelines are likely to be product-specific and all-encompassing, examining the "totality of evidence" available about a particular class of biotech drugs.
Speaking directly to the medical community, the FDA said it may have to review everything from the specific populations targeted by drugs and the process by which they are made.
Only then will the FDA suggest what clinical trials companies should conduct to verify any remaining doubts about safety or efficacy.
"The FDA is currently considering how such interactions (with companies) might be structured and how they will affect the user-fee program that Congress has mandated for biosimilars," the FDA said, referring to industry fees that drugmakers pay to help cover the costs of drug reviews.
FINDING THE FINGERPRINT
Many drugmakers await the market for biosimilars, including traditional generic manufacturers such as Israel's Teva Pharmaceuticals TEVA.O, makers of branded biotech drugs like Amgen (AMGN.O) and Roche (ROG.VX), and other big pharma companies, including Pfizer (PFE.N) and Novartis (NOVN.VX).
The market will range from relatively simple molecules like insulin to far more complex anti-cancer antibody medicines, growing to $3.7 billion by 2015 from just $243 million in 2010, according to a report from market analysis firm Datamonitor.
In 2009, Congress asked the FDA to develop a faster pathway for approving biosimilars to reduce the cost of biotech drugs. The agency plans to issue guidance this year. [ID:nN09164934]
Regulatory oversight of generic versions of traditional pills and capsules has been in place for decades. They are relatively easy to replicate and prove equivalence to branded medicines.
Agreement on a pathway for producing cheaper versions of biotech drugs -- which treat diseases like cancer, arthritis and multiple sclerosis -- has been far more difficult because of their complex manufacturing process.
Making biotech copies is also more costly, as manufacturers must conduct extra clinical trials to show the new version is as good as the old one.
However, new technologies that can more accurately describe the unique "fingerprint" of a biotech medicine can help more easily compare it to a copycat version, FDA officials said.
While this "fingerprint" technology is in its early stages, extra animal and clinical trials will still be required "for the foreseeable future," the officials wrote.
Some biosimilars are already available in Europe, including versions of Amgen Inc's anemia drug Epogen, and companies are launching partnerships. [ID:nL6E7HL0HB]
The European Medicines Agency (EMA) published guidelines for biosimilars in 2005, and approved the first such drug in 2006. FDA officials said they are studying European regulations, and will likely follow the EMA's approach of product-specific requirements for different biosimilars.
Despite the FDA's efforts to develop guidelines, other U.S. regulations may discourage some biosimilar makers by giving more protection to branded biotech therapies.
Under the U.S. healthcare law passed last year, brand-name biologic drugs -- which can carry annual price tags in the tens of thousands of dollars -- were granted a 12-year period of market exclusivity before generic versions can be sold.
Some potential biosimilar producers may prefer to alter an existing molecule to improve efficacy or safety, turning it into a new drug in the eyes of the FDA and securing an additional 12-year exclusivity. (Editing by Michele Gershberg, Phil Berlowitz)