Biosimilars
Biosimilar epoetins: how similar are they?
As the patent expiry dates of the original erythropoietins drew near, much concern was expressed in 2004 about possible biosimilar competitors. Product quality, safety and efficacy of biopharmaceuticals are highly dependent on the processes of production, purification and formulation. How have these genuine concerns been answered by the EMA in granting marketing approval, and have any other problems come to light?
Cipla invests in biosimilars
India-based generics’ manufacturer Cipla is increasing its presence in the biosimilars’ market with major investments planned for the near future, according to a report in the Indian newspaper Business Standard.
Highs and lows for biosimilars during 2009/2010
A lot has happened in the biosimilars’ industry during 2009/2010.
Dr Reddy’s launches biosimilar Aranesp
Dr Reddy’s Laboratories increases its stake in the biosimilars’ market with the latest launch in India from its biosimilars’ programme. Cresp is the first generic darbepoetin alfa in the world, and the only darbepoetin alfa in India. Darbepoetin alfa is used for the treatment of anaemia due to chronic kidney disease and chemotherapy.
Good news for biosimilar enoxaparin sodium
French pharma giant sanofi-aventis (sanofi) has been denied a request to block sales of a generic version of its Lovenox blood thinner by a US district court.
How far does similarity go?
How much similarity does a biosimilar monoclonal antibody (mAb) have to show to its reference mAb? The European overarching biosimilar guideline states that a biosimilar needs to be ‘similar, in molecular and biological terms, to the active substance of the reference medicinal product.’ The guideline gives an example to highlight this, stating that an interferon alfa-2b would not be acceptable as a reference product to a biosimilar interferon alfa-2a1. Because interferon alfa-2a and alfa-2b differ in only one amino acid, the guideline thus indicates that the entire amino acid sequence of the two molecules should be identical.
What clinical trials will be required for biosimilar mAbs?
The relevant European guideline states that if the reference medicinal product has more than one indication, the efficacy and safety of a biosimilar has to be justified, if necessary by demonstrating it separately for each indication claimed. The guideline brings up the possibility of ‘extrapolating’ efficacy (granting several clinical indications that are licensed for the reference product, although only one of the indications has been studied in the clinical development programme of the biosimilar). This would not be done without serious consideration. The mechanism of action of monoclonal antibodies (mAbs) is usually complex and in many cases only partially understood.
Technical challenges in defining mAbs
Monoclonal antibodies (mAbs) are highly complex molecules with secondary and tertiary structures. The drug substance (the molecule itself) and drug product (the pharmaceutically formulated final product) are heterogeneous, i.e. a mixture of several slightly different structures. Although the molecular characterisation of a mAb molecule itself might have reached a high level of precision, reliability, quality and reproducibility, various possibilities for mAb heterogeneity exist. Variations to the mAb protein include alternative disulfide pairings/disulfide shuffling, deamidation, (methionine) oxidation, cyclisation of N-terminal glutamine residues and partial enzymatic cleavage during manufacturing. Variations of post-translational modifications such as glycosylation patterns include differential addition of sugars, alternative branching of sugar chains and others. Physicochemical characterisation of these characteristics currently remains cumbersome.
Phase I trial of a biosimilar erythropoietin
A Phase I clinical trial of Hospira’s biosimilar erythropoietin (EPO) in patients with anaemia associated with chronic renal failure and chemotherapy has started in the US.
FDA approves first biosimilar enoxaparin sodium
On 23 July 2010, Momenta Pharmaceuticals and Sandoz announced that they had received approval from the FDA for their biosimilar version of sanofi-aventis’s (sanofi-aventis’s ) blockbuster blood thinning drug, Lovenox (enoxaparin sodium).
