The following key considerations for interchangeabilty should be addressed before any biosimilar is designated as interchangeable, according to Dr Brad Jordan, Director of Global Regulatory and R & D Policy at Amgen :
- Policies should address medically-guided and pharmacy mediated scenarios
- Decisions should be based on product-specific evidence
- Patients and prescribers should have options and input
- Policies and practices should support product-specific pharmacovigilance
Dr Jordan outlined five principles that address these key considerations, the first of which, that biosimilarity is not the same as interchangeability, is covered in this article.
Issues associated with the fact that biosimilarity is not interchangeability include:
- Biosimilarity is necessary, but not sufficient
- Equivalent outcomes at the population level do not prove equivalent response at the patient level
- Historical experience should not be extrapolated to other products
In fact, according to the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA), ‘risk assessments based on switching studies involving one class of biotherapeutics should not be generalized to other classes’. The association adds that ‘there is also no robust evidence as to whether switching may be harmful or not to patients based on the historical experience with medically supervised switching for certain classes of biotherapeutics’ .
1. In a survey of switching studies for somatropins, epoetins and filgrastims, Ebbers et al. stated: ‘does historical switching between filgrastims say anything about risks for anti-TNF therapies for inflammatory conditions?’. They found that ‘data on the frequency of switching in clinical practice is scarce’. However, they also concluded that they ‘found no evidence from clinical trial data or post-marketing surveillance data that switching to and from different biopharmaceuticals leads to safety concerns’ .
2. Australia’s Pharmaceutical Benefits Advisory Committee (PBAC) permitted substitution (‘a-flagging’) of biosimilars of infliximab and etanercept  but not biosimilar follitropin.
The PBAC has said that the absence of significant differences in safety and efficacy, along with data in treatment-naïve patients and data to support switching would support ‘a’ flagging of a biosimilar .
Dr Jordan believes that the following need to be taken into account when designating a biosimilar as interchangeable:
- A competent authority should make a case-by-case determination about biosimilar interchangeability
- Otherwise, prescribers should be involved in decisions to transition patients to biosimilars
The IFPMA has recommended that the prescribing physicians retain the right to designate which biological should be dispensed on the basis of clinical judgement .
Interchangeability of biosimilars in the US
Biosimilarity does not mean extrapolation of all indications
1. Jordan B. Regulatory implications for implementing biosimilar interchangeability: addressing policy and practical concerns. SMi 3rd Annual Biosimilars USA Conference; 16-17 November 2016; Iselin, New Jersey, USA.
2. IFPMA Policy Position. Pharmacy-mediated interchangeability for Similar Biotherapeutic Products (SBPs); [cited 2017 Apr 21]. Available from: www.ifpma.org/wp-content/uploads/2016/05/IFPMA-Policy-Position-PM-Interchangeability-of-SBPs-April-2016-vFINAL.pdf
3. Ebbers HC, Muenzberg M, Schellekens H. The safety of switching between therapeutic proteins. Expert Opin Biol Ther. 2012 Nov;12(11):1473-85. doi:10.1517/14712598.2012.711308. Epub 2012 Jul 31.
4. GaBI Online - Generics and Biosimilars Initiative. Australia says etanercept biosimilar can be substituted [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2017 Apr 21]. Available from: www.gabionline.net/Biosimilars/News/Australia-says-etanercept-biosimilar-can-be-substituted
5. GaBI Online - Generics and Biosimilars Initiative. Australia’s PBAC recommends substitution of biosimilars [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2017 Apr 21]. Available from: www.gabionline.net/Biosimilars/General/Australia-s-PBAC-recommends-substitution-of-biosimilars
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