Acadia’s external provider R & D costs for trofinetide, as...

Acadia’s external provider R & D costs for trofinetide, as recorded in the company’s SEC filings, currently total US$195m (A$288m). This includes R & D costs incurred since 2018 until the end of Q3 2023. It doesn’t include internal R & D costs, any upfront or milestone payments or any commercialisation costs for the drug.

This figure is obviously well above the figure suggested by Dame Margaret Brimble. I suspect that her belief that the Phase 3 cost was $54m was likely informed by the US$55m figure provided by Neuren as an estimate of the cost of the Rett Phase 3 trial at the time of announcement of the licensing agreement with Acadia in August 2018.

As we have learned from the development of trofinetide by Acadia, post-Phase 2 development can entail much more than a single pivotal trial.

Not only was there the 187 patient Lavender pivotal trial in women and girls, there was the Lilac-1 extension study of 40 weeks, followed by the Lilac-2 open label extension study of a further 32 weeks. Then there was the Daffodil study in 2-5 yr olds. Acadia also completed studies examining the influence of timing of food intake on the action of the drug, the effect of concomitant epilepsy medication and how to manage diarrhoea. As required by the FDA, a Phase 4 study (LOTUS) has already been launched to monitor post-approval use of the drug in the Real World Setting.

Clinical trial costs in the United States are the highest in the world and will have risen substantially during the past few years due to Covid and post-Covid inflationary pressures.

I note that Karuna Therapeutics incurred R &D costs of ~US$225m, last year, with R & D costs rising to ~US$100m per quarter this year.