The clarification came at a recent parliamentary question-and-answer session on biosimilars. "This is the first time the government has been asked about this from a reimbursement perspective, so this is the first time we have given clarification," a health ministry spokesperson said.

Under the Dutch preference policy system, insurers can choose to reimburse only a certain selected generic medicine, unless the doctor specifies on the prescription that the patient might have an adverse reaction to that particular product. In the same way, insurers can select a biosimilar for reimbursement, Health Minister Ab Klink confirmed.

The minister's comments came in response to a question on whether insurers could cut spending on growth hormones by Euros 10 million by extending their preference policies to include "the most cost-efficient variant of growth hormones".

"From a legal point of view, there is no distinction between generic medicines and biosimilars with regard to preference pricing," said Mr Klink during the Q&A session. "The use of preference policies to increase the prescribing of more cost-efficient biosimilars is therefore a distinct possibility with respect to new patients," he added.

However, only a doctor can decide whether or not to transfer an existing patient onto a biosimilar. "Biosimilars are not the same as a generic. For new patients it doesn't really make a difference, but switching patients to biosimilars is not so clear-cut," said the health ministry spokesperson. He added that transferring patients to other biosimilars or the reference products was more complicated at an individual level. Intervention from a physician was therefore necessary owing to the possible differences between the medicines.

However, Sandoz, a pioneer in the field, said that biosimilars should be viewed as interchangeable because they were "approved across the EU on the basis that they have demonstrated comparable quality, safety and efficacy to the reference product". Nevertheless, the firm conceded that decisions on substituting medicines should be made at a national level, he added.

Meanwhile, the research-based industry seems to be viewing the move with some caution. Biosimilars could be appropriate for new patients, says Nefarma, the Dutch pharmaceutical industry association. But it was keen to emphasise that biosimilars were not common generic medicines. "The way that they work differs so much from ordinary drugs that they need a special approach, therefore we are against a policy to switch medication for patients already using biological medicines. Our slogan is: 'Don't change medication if the treatment of the patient is going well'," said a spokesperson.

The Dutch health ministry is fully behind biosimilars, which it says are as good as the originators but less expensive. Added to this, generic medicines represent just under 60% of the unprotected market in The Netherlands, says IMS Health. This is a strong indicator that biosimilars will gain widespread acceptance there, especially in comparison with markets where generic penetration is still low, such as Greece, Ireland and Spain.

Sandoz, which has arguably pioneered biosimilars, said that it was too early to say what the impact of the ministry's decision might be on the uptake of biosimilars in Europe. But it added that the move seemed "in line with the growing Europe-wide tendency towards greater acceptance of biosimilars".

Sandoz, the only company with more than one biosimilar on the European market, developed Omnitrope (somatropin), the first ever biosimilar to be approved. The EU gave this the green light in 2006, followed by Canada and Japan earlier this year. Sandoz also won EU approval for the first complex biosimilar Binocrit (epoetin alfa) in 2007, and Zarzio (filgrastim) in February 2009. It said that it was looking forward to developing monoclonal antibodies, which would offer "many of the major upcoming opportunities".