Last week, Health Canada approved Celltrion and Teva’s biosimilar rituximab, Truxima, for the treatment of adults with non-Hodgkin lymphoma, chronic lymphocytic leukemia, and rheumatoid arthritis.

"Biosimilars are a new chapter in the therapeutic oncology setting in Canada and represent a growing focus for Teva since they will allow us to increase access to important therapeutic options," said Christine Poulin, senior vice president and general manager of Teva Canada, in a statement announcing the approval. "Moreover, Teva's biosimilars will have the potential to reduce costs by providing lower-cost treatment options for patients."

The Canadian regulator based its assessment of the biosimilar on a data package including analytical characterization, nonclinical data, pharmacology, immunogenicity, efficacy, and safety data.

The same biosimilar rituximab product was approved in the United States, also under the name Truxima, in November 2018. However, unlike Health Canada, the FDA only approved the product for use in oncology indications. In the European Union, the biosimilar is also approved to treat granulomatosis with polyangiitis and microscopic polyangiitis. Celltrion representatives explained during an FDA advisory committee meeting that it was seeking only indications for malignant diseases due to the patent landscape in the United States.

In a recent interview with The Center for Biosimilars®, Kashyap Patel, MD, medical oncologist, Carolina Blood and Cancer Care, said that he anticipated that US physicians would likely be willing to use the biosimilar in indications for which it was not approved by the FDA because of the patent protection issues.

Patel said that he not be surprised to see physicians adopt the biosimilar for other indications on the basis of extrapolation. He noted that, in oncology, approximately one-third of product use is based on either extrapolation or a compendium listing, so it would not be unlikely that, with growing concerns about cost and growing acceptance of biosimilars, CT-P10 could find its way to patients who need treatment with rituximab for indications outside of those for which the product gained its FDA approval.

However, Ali McBride, PharmD, MS, BCPS, clinical coordinator of hematology/oncology, the University of Arizona Cancer Center, also in an interview with The Center for Biosimilars®, explained that he had open questions related to whether payers would be amenable to reimbursing the biosimilar product for unapproved indications.

According McBride, payer decisions about the biosimilar will be pivotal, and discussions with payers about this product will be “very different” from discussions related to those concerning off-label indications, and that fact could lead to logistical problems.

“We're really looking for some guidance in this area with payers. I think payers need to actually voice some of this discussion early on so we can kind of guide ourselves [on] what to do, because if we don't, we may need to actually have a brand-name drug therapy out there and also a biosimilar drug out there on the same shelf because payers may have different understandings of what that off label discussion will be from implementation of biosimilar rituximab,” said McBride.

No launch dates for Truxima have been announced for the biosimilar in either the US or Canadian markets.