Canada’s regulatory agency, Health Canada, is asking drugmakers seeking approval of similar drugs containing low molecular weight heparins (LMWHs) to use the approval pathway for subsequent entry biologics (SEBs), as they are called in Canada.

Health Canada’s Biologics and Genetic Therapies Directorate (BGTD) issued a policy statement on 16 August 2013 describing the agency’s approach to regulating LMWHs containing medicinal products claiming to be similar to another heparin which is already marketed.

The announcement clarifies Health Canada’s position regarding LMWHs as biological and not chemical entities. This has been discussed in the past, due to the fact that Sandoz’s version of enoxaparin, for example, is not a therapeutic protein produced from a living system, such as a cell culture and was approved in the US using an abbreviated new drug application (ANDA). However, the treatment of enoxaparin as a non-biological drug has been questioned, as the blood-thinning medicine consists of a highly complex mixture of polysaccharide molecules of variable chain lengths and molecular weights.

The BGTD states in its announcement that LMWHs ‘are a complex mixture of polysaccharide polymers, whose components are not fully characterized’ and ‘given the complex and heterogeneous nature of LMWH, it is the position of BGTD that it is not currently possible to demonstrate that two LMWH products contain identical amounts of the identical medicinal ingredients. As such, the [abbreviated new drug submission] ANDS regulatory pathway [of Health Canada], which relies on this demonstration, is inappropriate for LMWH[s].’

The BGTD’s position is in line with that of European Medicines Agency, which also regards similar drugs containing LMWHs as biosimilars and not as generics.

Related articles

Health Canada announces plans to tackle drug shortages

Canadian guidelines for biosimilars

Source: www.gabionline.net