Patent expiries have been hitting the books of the big players across the industry, but careful management of the lifecycle of a drug, for example by developing improved formulations, can limit the impact. The recent US approval of Janssen Pharmaceutica's Risperdal Consta (risperidone) for schizophrenia is a prime example of the value in this approach.
Risperdal Consta is a two-week, intra-muscular injectable version of Risperdal (risperidone), first launched in the US in 1997 and due for patent expiry in 2007. Risperdal is Janssen's most important product, bringing in sales of over $2.5 billion in 2002. Patent expiry in December 2007 will lead to a $1 billion-plus loss in revenues in 2008, due to generic sales erosion, according to analysts at market research firm Datamonitor.
Despite the increasing competition from product reformulations and generics, Risperdal Consta should ensure that Risperdal remains a blockbuster until 2011, said Datamonitor.
The new version is the first long-acting drug in the atypical antipsychotic class to be launched in the US, although it has been rolling out in other countries since making its debut in Germany last year. It is based on the Medisorb drug-delivery technology, developed by drug delivery specialist Alkermes, and provides a continual release of the drug over the two-week period.
It is estimated that more than 2 million Americans suffer from schizophrenia and there is a huge problem with treatment compliance among patients. However, non-compliance should be reduced in patients prescribed Risperdal Consta, as the drug is administered by healthcare workers every two weeks.
The US launch of Risperdal Consta extends the existing range of formulations, which include a once-daily tablet, an orally disintegrating tablet, and an oral solution.
At present, the antipsychotic pipeline for new treatments is relatively weak with no drugs anticipated to enter the market until 2006. Consequently, competition is derived primarily from product reformulations, exemplified by Eli Lilly's market leading Zyprexa (olanzapine), which is expected to gain US Food and Drug Administration (FDA) approval in early 2004 as a short-term injectable formulation.
However, the US patent expiry of Pfizer's Geodon (ziprasidone), also in 2007, will provide further generic competition to atypical antipsychotics.