- Recent clinical results are strengthening the case that Pfizer and Celltrion's biosimilar Inflectra (infliximab-dyyb) will meet recently minted interchangeability guidelines.
- Top-line results from a Phase 3 trial testing the drug against its reference product, Johnson & Johnson's Remicade infliximab), in patients with moderate-to-severe Crohn's disease showed both treatments had similar effectiveness and safety profiles.
- The study is also evaluating how patients respond to switching from Inflectra to Remicade treatments and vice versa. Should that data show little difference between the two drugs, it would support an interchangeability classification, which would allow pharmacy's to dole out the copycat drug instead of Remicade without a doctor specifically prescribing the biosimilar.
The Food and Drug Administration released draft guidance back in January concerning interchangeability requirements, which none of the biosimilars approved in the U.S. have met so far. Switching studies like the one Pfizer and Celltrion are running for Inflectra are one such requirement, but the companies still have to prove that their drug yields "the same clinical result as the reference product in any given patient," according to the FDA.
Though it's too early to say, the already released results are a boost of confidence that interchangeability is achievable for Inflectra. Pfizer and Celltrion expect to release a more thorough readout of the study later this year.
Inflectra's can't celebrate just yet, however. Johnson & Johnson's subsidiary Janssen is fighting with Celltrion over patent protections related to Remicade, and has appealed a district court decision that ruled in favor of the South Korean pharma.
For Johnson & Johnson, the fight is well worth it. Remicade sales totaled $6.97 billion in 2016, up from $6.56 billion in the year-prior. While the drug is older and already facing biosimilar threats, as well as competition from a swath of other drugs in the space, J&J has been able to maintain its market. Yet, that is soon to change, and that competition could erode about 10% to 15% of Remicade's market share, J&J's CFO Dominic Caruso said during a Jan. 24 earnings call.
The newest Inflectra clinical results aren't likely to alleviate those competitive concerns either.
The randomized, double-blind, parallel-group study tested 214 patients with Crohn's over a 54-week period, and met its primary endpoint — demonstrating that Inflectra efficacy and safety were not statistically significantly different from that of Remicade — by the end of the sixth week. Response rates for treatment with Inflectra or Remicade were 71.4% and 75.2%, respectively, as measured by the number of patients who had at least 70-point reductions on the Crohn’s Disease Activity Index.