iologic drugs account for a large proportion of Canadian drug spending. As in many other countries, the development of a robust biosimilars market is looked at by Canadian drug payers as one way to support healthcare budget sustainability. However, a recent study reports that uptake of biosimilars in Canada is relatively low compared to other countries in the Organization for Economic Cooperation and Development (OECD).

From the regulatory perspective, biosimilars are reviewed by Health Canada as new drug submissions (300-day review target), with requirements that are aligned with those of other major regulatory jurisdictions. The basic requirements for a biosimilar submission:

• A suitable reference biologic drug exists that (a) was originally authorized for sale based on a full quality, non-clinical and clinical data package; and (b) has been used in the post-market setting such that the demonstration of similarity will bring into relevance a substantial body of reliable data on safety, efficacy, and effectiveness.
• The biosimilar and reference biologic drug can be well-characterized by a set of modern analytical methods.
• The biosimilar, through extensive characterization and analysis, can be judged similar to the reference biologic drug by meeting an appropriate set of pre-determined criteria.

Extensive manufacturing data including comparative studies are required to establish similarity with the reference product. In vivo non-clinical data may not be required, provided good evidence of similarity and a scientific rationale. Clinical studies should include PK/PD data and, in most cases, a comparative clinical efficacy study, preferably an equivalence study, rather than a non-inferiority trial.

Sponsors of a biosimilar may apply for the same indication(s) as the reference product, but the indications granted will depend on the evidence provided to demonstrate similarity and a detailed scientific rationale for each indication. Risk management plans are also required. A recent decision on biologic naming has been published; biologic drugs, including biosimilars, will be identified by their unique brand name and non-proprietary (common) name. Product-specific identifiers such as the brand name or drug identification number (which is a unique number granted by Health Canada) should be used throughout the medication use process and in adverse reaction reporting to support best practices in product tracking.

Similar Is Not Equivalent

Although the authorization of a biosimilar means that the product has been determined to be similar, the biosimilar product is not determined by the regulator to be pharmaceutically-equivalent, bio-equivalent, or clinically-equivalent. With regard to interchangeability (often defined as the ability for a patient to be changed from one drug to another equivalent drug by a pharmacist without the intervention of the prescriber), the authority to declare a biosimilar and its reference biologic drug to be interchangeable rests with each province and territory according to its own rules and regulations.

In addition to the regulatory review, additional players in the Canadian healthcare system are adapting to biosimilars and working to support uptake. With respect to health technology assessment, the Canadian Agency for Drugs and Technologies in Health has introduced a streamlined review process, which has reduced requirements and implemented a shortened review time. Biosimilars are also eligible for inclusion in the aligned review process, which allows Health Canada and the health technology assessment bodies to share information.

The pan-Canadian Pharmaceutical Alliance, which collectively negotiates prices for provincial and federal drug plans, has issued general guidelines for how they will approach negotiations for biologic drugs. These include considering biologic drugs on an individual basis in their market context, but beginning negotiation for biosimilars while the health technology assessment review is ongoing, and explicitly stating that the switching of patients from a reference biologic to a biosimilar may be implemented.

Most of the early biosimilars authorized in Canada were in the rheumatology space. Now, however, as innovator patents expire and additional biosimilars are launched, new products for oncology are expected to grow. In order to support adoption of biosimilars, the pan-Canadian Oncology Biosimilars Initiative has set out an action plan which proposes the following:

• Stakeholder education and engagement
• Dissemination of best practices for implementation, considering such aspects as storage, labelling, prescribing, and dispensing
• Supporting reimbursement strategies that promote implementation of oncology biosimilars
• Developing clinical guidance on initiating and switching
• Developing an evaluation and monitoring plan that relies on real world evidence
• Re-investing any savings back into the cancer care system

As more biosimilars enter the market, the impact of such strategies on adoption will be interesting to follow.

Additional References