Nasal route could save cold drug
for approval by the US Food and Drug Administration last year could
find a new lease of life in an oral formulation, according to its
developer. If this is correct, the drug could become the first drug
ever approved as a treatment for colds.
Pleconaril will be developed in an intranasal formulation by its developer ViroPharma in collaboration with Schering-Plough. The two companies have signed an agreement in which S-P has paid $3 million for an option to license the new formulation, designed to overcome the primary obstacle to approval of the older oral form, in the US and Canada.
The FDA issued a 'not approvable' notice to ViroPharma last year for the oral form of pleconaril - developed in tandem with Aventis under the Picovir brand name - after concluding that there was not enough data on its safety to warrant its use in what is generally a low-risk, self-limiting infection. However, the agency agreed that there seemed to be some evidence of efficacy, with pleconaril shortening the duration of cold symptoms.
Aventis bailed out of the agreement at this point, but ViroPharma persisted, reasoning that a localised route of administration that reduced systemic absorption of the drug may overcome the safety objection.
The funding from S-P will allow ViroPharma to conduct some proof-of-principle clinical trials of the intranasal formulation. These will assess whether giving pleconaril via this route will be safe and retain its antiviral activity, as well as checking whether the formulation is robust enough to become a commercial product.
"We hope to demonstrate that this formulation can deliver significantly more drug to the site of active common cold infection than the oral formulation, while limiting its systemic exposure and, thereby, minimising the risk of drug interactions," said Mark McKinlay, ViroPharma's vice president of R&D.
The results of the trials should be available in the middle of next year and, if S-P opts to take a full license to the product, ViroPharma stands to receive an additional $10 million, as well as an undisclosed fee for the bulk purchase of all its supplies of bulk pleconaril.
Under the terms of the agreement, ViroPharma would also be eligible for additional milestone payments, well as royalties on S-P's sales of the drug.
