Generating impressive results and rushing your product to market as rapidly as possible is a time honoured tradition in the biopharmaceutical world, though Acadia Pharmaceuticals announced plans to go another way this week – not because it lacks confidence in pimavanserin's clinical profile, quite the opposite in fact.
Last June, Acadia introduced pimavanserin in the US where the inverse 5-HT2A serotonin receptor agonist is sold as Nuplazid for the treatment of Parkinson's disease psychosis (PDP). Adoption of the drug has been brisk in the months since, with 3Q16 sales of $5.3 million easily outpacing the consensus estimate of $3 million, suggesting a strong demand for Nuplazid despite it being saddled with a label containing a black box warning about an increased risk of death in elderly patients (see ViewPoints: Acadia’s Nuplazid launch will require an outside-the-box approach).
From a long-term perspective, one of the most crucial questions facing Acadia is whether it would be successful in expanding pimavanserin's label to include an array of related indications in patients with Alzheimer's disease (AD) and schizophrenia, which could drastically expand the drug's market potential.
Acadia announced top-line results from a Phase II trial in December in one of the first the line-extension indications that showed the compound met the primary endpoint by significantly reducing Neuropsychiatric Inventory-Nursing Home (NPI-NH) Psychosis score at week 6 in patients with AD psychosis (see ViewPoints: Pimavanserin’s success in Alzheimer’s psychosis could be unexpected upside – but extenuating circumstances abound).
At the time, Acadia said it was sufficiently encouraged by the activity seen to move pimavanserin ahead into Phase III testing for AD psychosis, but CEO Stephen Davis went a step further at the JP Morgan Healthcare Conference this week by announcing that the company has become confident enough in the drug's profile that it has decided to delay plans to seek approval in the EU.
The decision may sound counterintuitive at first blush but according to Davis makes sense given the peculiar manner in the way marketing exclusivity is awarded in the region, where a 10-year clock starts after an initial approval is granted. As a result, it could behove a company to hold off on the initial approval if results from another – potentially even larger – indication may be just around the corner.
"We were ready to push the button," on the MAA submission this fall, noted Davis, "but then got the AD psychosis results that moved the needle in favour of waiting. It is a trade-off between potentially launching sooner, but with less time with additional indications versus frame-shifting and having more time with new indications," but having to wait longer before starting to sell the product in Europe.
In the meantime, Davis said the company has already embarked on an expansion of its sales force in the US to improve penetration within long-term care facilities, while more studies in additional line-extension indications remain ongoing.
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