GW shaky on latest setback

GW Pharmaceuticals will hope that yesterday’s failure of its second-most advanced cannabinoid project, GWP42006, is not a bad omen for the main event this year: approval of its lead compound, Epidiolex.

Epidiolex will face an FDA advisory committee in April, and analysts seem convinced that this will be a mere formality ahead of the project’s PDUFA date of June 27. With questions remaining over Epidiolex’s abuse potential and whether GW can launch the product alone, the company could do with things going to plan.

This was not the case yesterday, when a phase IIa trial of GWP42006 in adults with focal seizures flopped; GW’s stock was down as much as 6% this morning. The company blamed a high placebo response, and said it had not given up on GWP42006 in epilepsy.

GW is also evaluating GWP42006 in autism spectrum disorder and the rare neurodevelopmental disorder Rett syndrome, with various trials slated to start this year.

GWP42006 development
Indication Trial Details
Focal seizures Phase II trial; NCT02365610 Failed
Autism spectrum disorder 10-patient investigator-led expanded access programme Under way
  100-patient investigator-led placebo-controlled trial To start Q2 2018
Rett syndrome Open-label study To start Q2 2018
  Phase II placebo-controlled trial To start Q3 2018

The sellside tried to shrug off the setback, with Leerink analysts noting that their valuation of GW was driven by Epidiolex and cash, with no contribution from GWP42006. Still, the analysts had highlighted promising preclinical data with GWP42006 and said in January that they were cautiously optimistic on the project. Surely GWP42006’s chances in other indications have now taken a nosedive too.

Hopes are much higher for Epidiolex, with EvaluatePharma sellside consensus forecasting 2022 sales of $1.1bn. The project is filed for approval in Lennox-Gastaut and Dravet’s syndromes, two rare childhood epilepsy types, while pivotal data in tuberous sclerosis are due towards the end of the year.  

The highly encouraging results in Dravet and Lennox-Gastaut syndromes have raised hopes for approval. The Leerink analysts believe that the FDA’s mandating of an adcom, set for April 19, has less to do with the clinical data and more with the nature of the project; there could be concerns about the use of cannabinoids in children.

A related point is how Epidiolex’s abuse potential might be classified by the US Drug Enforcement Administration. DEA scheduling should happen within 90 days of approval, after which GW can launch, so Epidiolex could debut in September.

GW will no doubt hope for a relatively benign classification, perhaps in line with its first cannabinoid project, Sativex, which is approved outside the US and has been designated schedule IV in the UK, indicating low abuse potential.

Perhaps a more crucial question is whether GW, long rumoured as an acquisition target, will be able to meet Epidiolex’s hefty sales expectations alone. The group has been busy building its commercial team and will be targeting 4,000-5,000 doctors in the US, a big undertaking for a small company.

And GW has a potential competitor in Zogenix. The latter’s Fintepla is further behind in development, but available data suggest that Fintepla could be more effective than Epidiolex, at least in Dravet syndrome (Dravet hit makes Zogenix another September biotech winner, September 29, 2017). Zogenix started a phase III trial in Lennox-Gastaut syndrome in November.

GW always needed Epidiolex to deliver. GWP42006’s failure has ratcheted up the pressure another notch.

To contact the writer of this story email Madeleine Armstrong in London at madeleinea@epvantage.com or follow @ByMadeleineA on Twitter

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