Acadia Expects Negative CHMP Opinion for Rett Syndrome Drug in EU

Acadia Pharmaceuticals ACAD announced that it expects to receive a negative opinion from the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) for the marketing application for trofinetide to treat Rett syndrome, following a recent oral explanation.

Acadia was informed by the CHMP of a negative trend vote on its marketing application for trofinetide to treat Rett syndrome. Pending the outcome of the CHMP vote this month, Acadia plans to seek a re-examination of the CHMP opinion once it is formally adopted.

With the CHMP likely to reject the marketing application for trofinetide in Rett syndrome, a potential approval in the European Union is likely to be delayed.

Rett syndrome is a rare neurodevelopmental disorder affecting about one in 10,000-15,000 female births worldwide. After a period of apparently normal early development, symptoms typically emerge between six and 18 months, followed by loss of acquired skills. While some stabilization may occur, patients often experience ongoing motor deterioration over time.

The FDA approved trofinetide for the treatment of Rett syndrome in adults and pediatric patients aged two years and older in 2023. The drug is marketed under the brand name Daybue in the United States.

ACAD’s Price Performance

In the past six months, shares of Acadia have increased 8.6% compared with the industry’s rally of 18.8%.

ACAD's Marketed Drugs Expected to Aid Growth

Despite the latest hurdle, Acadia remains positioned for long-term growth, supported by its lead product, Nuplazid, and Daybue in the United States. The company expects to generate around $1.7 billion in combined net sales by 2028, including around $1 billion for Nuplazid and around $700 million for Daybue.

Nuplazid is the first and only FDA-approved treatment for hallucinations and delusions associated with Parkinson’s disease psychosis in the United States. The drug enjoys patent protection in the United States until 2038, which gives it a long runway for revenue generation by protecting against generic erosion. In the first nine months of 2025, Nuplazid recorded $505.7 million in sales, up 13% year over year, driven primarily by volume growth.

Since its launch in 2023, Daybue has been witnessing encouraging sales uptake in the United States. In the first nine months of 2025, Daybue recorded $281.8 million in sales, up 12% year over year, driven by growth in the drug’s unit sales as the company shipped it to more unique patients.

The FDA recently approved Daybue Stix (trofinetide) for oral solution, a dye- and preservative-free powder formulation for the treatment of Rett syndrome in adults and pediatric patients aged two years and older. The new product expands the Daybue franchise, which remains the only FDA-approved treatment option for this indication.

Acadia plans a limited launch of Daybue Stix during the first quarter of 2026, followed by broader availability in the second quarter. The company will continue to offer the current oral solution alongside the new formulation, strengthening its positioning in the Rett syndrome treatment market.

ACAD's Zacks Rank & Stocks to Consider

Acadia currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks in the biotech sector are Alkermes ALKS, Castle Biosciences CSTL and Immunocore IMCR, each sporting a Zacks Rank #1 (Strong Buy) at present. You can see the complete list of today’s Zacks #1 Rank stocks here

Over the past 60 days, estimates for Alkermes’ 2026 earnings per share (EPS) have increased from $1.54 to $1.91. Shares of ALKS have gained 30.6% over the past six months.

Alkermes’ earnings beat estimates in three of the trailing four quarters, while missing the same on the remaining occasion, with the average surprise being 4.58%.

Over the past 60 days, Castle Biosciences’ loss per share estimates for 2026 have decreased from $1.06 to 50 cents. Shares of CSTL have surged 157.8% over the past six months.

Castle Biosciences’ earnings beat estimates in three of the trailing four quarters, while missing the same on the remaining occasion, with the average surprise being 66.11%.

Over the past 60 days, Immunocore’s loss per share estimates for 2026 have decreased from 97 cents to 90 cents. Shares of IMCR have risen 1.6% over the past six months.

Immunocore’s earnings beat estimates in three of the trailing four quarters, while missing the same on the remaining occasion, with the average surprise being 53.96%.

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This article originally published on Zacks Investment Research (zacks.com).

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