The European Medicines Agency (EMA) has adopted a guideline on Similar Biological Medicinal Products Containing Monoclonal Antibodies (MAbs), which will be released shortly for public consultation.

The guideline was approved late last week by the EMA’s Committee for Medicinal Products for Human Use (CHMP), and is expected to be published on the Agency’s website within the next few weeks. The consultation period will be for five months.

A statement from the EMA noted only that the guideline “lays down the nonclinical and clinical requirements for [MAb]-containing medicines claiming to be similar to another one already marketed.” However, many observers are forecasting that the Agency will take a cautious approach to approval of biosimilar antibodies, as the US Food and Drug Administration (FDA) was urged to do earlier this month during a public meeting held to examine how it should establish an approval pathway for biosimilars – also known as follow-on biologics (FOB) - overall, as it is required to do by the Biologics Price Competition and Innovation Act (BPCIA), which was included in the healthcare reform package signed into law by President Barack Obama in March.

The EMA framework for approving biosimilars, in place since 2004, was praised by Marie Vodicka, associate vice president of scientific and regulatory affairs at the Pharmaceutical Research and Manufacturers of America (PhRMA), who told the meeting: “we urge FDA to look to the EMA processes that enabled safe and effective biosimilars to reach European patients.”

Meantime, MAbs accounted for worldwide sales of more than $36 billion last year, and a new report forecasts that the sector will record a near double-digit growth rate over 2009-15, providing the highest and fastest growth across the prescription drug industry. However, it adds, there will be few opportunities for biosimilar MAbs.   

Only a very small number of MAbs are expected to lose patent protection over the coming six years, says the report, from Datamonitor. Moreover, it adds: “the major MAb brands that are set to see their primary patent expire over the coming six years have other competitive forces impacting their projected sales performances, namely competition from second-generation MAb products, and competition from small-molecule targeted therapies.”

The report’s authors believe that a regulatory framework for the approval of a biosimilar MAb will be approved by regulatory bodies and put in place “in the very near future,” but they “do not expect the introduction of a biosimilar MAb to erode sales of target branded prescription MAbs to the same extent that the entry of a generic small-molecule drug erodes sales of its target branded prescription drug.”

- The first biosimilar MAb to come to market in Europe is widely expected to be a copy of Roche/Biogen Idec’s rheumatoid arthritis and cancer drugMabThera (rituximab), whose European patent is due to expire in 2014. A number of companies are developing biosimilar versions, including Israel’s Teva and Dr Reddy’s of India.