“It doesn’t make sense to require multiple trials [for extrapolation],” Dr. Cohen says. “Most of the work has been done with assays that determine this is a highly similar molecule, with no impact on efficacy or safety.” Although this may involve some griping from certain specialists—say, gastroenterologists who may not have data available from specific studies of the biosimilar conducted in patients with ulcerative colitis or Crohn’s disease—Dr. Cohen points out that trials within rheumatoid arthritis (RA) and psoriasis have established outcome measures that are considered more sensitive to detect a difference in the biosimilar and the reference molecule than inflammatory bowel disease, which is why sponsors have chosen to test their biosimilars in RA and psoriasis.
The ACR states that it “does not support automatic extrapolation. We do believe that extrapolation should be rigorously studied and fully utilized to help reduce the cost of these drugs. Throughout the biosimilar approval process, care must be taken to ensure that a drug pursuing interchangeability has successfully demonstrated extrapolation for all indications for which the originator is approved.”
Extrapolation of indications is supported by 10 years of safety and efficacy experience in Europe, Dr. Worthing says.
Naturally, pricing of biosimilars is an issue of concern for insurers, manufacturers, physicians and patients. Dr. Gravallese believes that pricing is an important topic to address in any U.S. analysis of the role of biosimilars, including the upcoming ACR white paper.
“I would like to see biosimilars be used, because this will potentially lead to a lower medication cost. That’s something many of us would like to see happen,” Dr. Gravallese says.
One advantage of biosimilars so far is their cost, typically 15% lower than their reference product; however, Dr. Kay has seen examples of reference products that have been discounted to below the price of their biosimilars. “If that happened all the time, it might drive biosimilars out of the market. The survival of biosimilars is necessary to maintain a competitive marketplace and keep down the cost of effective therapies so that they are affordable for our patients,” he says.
In June, the U.S. Supreme Court overturned a lower court’s ruling that prevented Novartis from selling the biosimilar Neuopogen for six months after the U.S. FDA approval. That ruling is expected to help acceleration the entry of more biosimilars into the U.S. market, many predict.
ACR White Paper
To help address the issues mentioned above in the U.S. market, the ACR decided to produce a white paper on the topic of biosimilars. The rheumatologists quoted in this article are involved in the production of the white paper, as are a handful of others. Although there was originally talk about writing a review article on biosimilars, a paper that focuses on concerns specific to the use of biosimilars in the U.S. would likely be more beneficial, Dr. Gravallese points out.