ACAD Stock Up as CHMP Backs Daybu for EU Approval in Rett Syndrome

Acadia Pharmaceuticals ACAD shares climbed 6.8% on Friday after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion following a re-examination procedure, recommending the approval of Daybu (trofinetide) for the treatment of neurobeha…

Acadia Pharmaceuticals ACAD shares climbed 6.8% on Friday after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion following a re-examination procedure, recommending the approval of Daybu (trofinetide) for the treatment of neurobehavioral symptoms of Rett syndrome in adults and pediatric patients aged five years and older. The recommendation marks a major regulatory turnaround for the therapy, which could become the first approved treatment for this indication in the EU.

The positive CHMP recommendation represents an important milestone for Acadia as it seeks to expand Daybu's commercial footprint. Rett syndrome is a rare neurodevelopmental disorder with no therapies currently approved in the EU specifically for its neurobehavioral symptoms, leaving patients with limited treatment options. An approval would allow Acadia to address a significant unmet medical need while strengthening the long-term growth prospects of its rare disease franchise.

The CHMP's favorable opinion was primarily supported by data from the pivotal phase III LAVENDER study, which demonstrated statistically significant and clinically meaningful improvements in key measures of Rett syndrome. The study met its co-primary endpoints, showing benefits on the Rett Syndrome Behavior Questionnaire and the Clinical Global Impression-Improvement scale, indicating that Daybu can improve some of the core neurobehavioral manifestations of the disease that substantially affect patients' daily functioning and caregiver burden.

Following the CHMP recommendation, the European Commission (EC) will review the agency's opinion before issuing a final regulatory decision, which is expected in the coming months. If approved, Daybu's centralized marketing authorization would be valid across all 27 EU member states as well as Iceland, Liechtenstein and Norway, significantly expanding access to the therapy across Europe.

The FDA approved trofinetide as the first and only treatment for 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. Daybue is also marketed (and available) in Canada and Israel for the same indication.

Year to date, Acadia shares have lost 5.2% against the industry’s 5.2% growth.

Earlier CHMP Refusal Delayed EU Expansion of ACAD’s Daybu

The latest recommendation follows a significant regulatory setback earlier this year, when the CHMP formally adopted a negative opinion recommending against the approval of trofinetide for the treatment of Rett syndrome in patients aged two years and older in the EU. The decision came after the committee had previously notified Acadia of a negative trend vote on the marketing application in early February, prompting the company to seek a formal re-examination of the application.

Although the pivotal LAVENDER study had achieved its co-primary and key secondary endpoints, the CHMP had previously concluded that several aspects of the evidence package limited its ability to support approval. The committee viewed the treatment benefit observed after 12 weeks as modest, questioned whether the study adequately captured all core symptoms of Rett syndrome and expressed concerns that patient discontinuations may have affected the interpretation of longer-term outcomes.

Following the initial refusal, Acadia reviewed the CHMP's objections in detail and proceeded with the re-examination process, ultimately securing the positive recommendation now under consideration by the EC. The favorable outcome substantially improves the therapy's regulatory outlook in Europe and revives the company's efforts to bring Daybu to patients across the region.

ACAD's Marketed Drugs Expected to Aid Growth

Acadia’s long-term growth is 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 $1 billion for Nuplazid and $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 quarter of 2026, Nuplazid recorded $167 million in sales, up 5% year over year, driven primarily by volume growth.

Since its launch in 2023, Daybue has witnessed encouraging sales uptake. In the first quarter of 2026, Daybue recorded $101 million in sales, up 20% year over year, driven by growth in the drug’s unit sales as Acadia shipped it to more unique patients. A potential EU approval could further boost sales.

In late 2025, the FDA 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.

Per Acadia, the full U.S. launch of Daybue STIX is underway, with nearly 30% of patients using STIX either new to treatment or resuming therapy after previously discontinuing the liquid formulation. The company will continue to offer both formulations in the United States, strengthening its positioning in the Rett syndrome treatment market.

ACADIA Pharmaceuticals Inc. Price and Consensus

ACADIA Pharmaceuticals Inc. price-consensus-chart | ACADIA Pharmaceuticals Inc. Quote

ACAD's Zacks Rank & Stocks to Consider

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

Some better-ranked stocks in the biotech sector are Liquidia Corporation LQDA, Indivior Pharmaceuticals INDV 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 Liquidia Corporation’s 2026 EPS have increased from $1.50 to $2.97. Over the same period, EPS estimates for 2027 have also increased from $2.91 to $4.81. LQDA shares have rallied 126.7% year to date.

Liquidia Corporation’searnings beat estimates in three of the trailing four quarters and missed in the remaining one, with the average surprise being 54.40%.

Over the past 60 days, estimates for Indivior Pharmaceuticals’ 2026 earnings per share have increased from $3.34 to $4.05. Over the same period, EPS estimates for 2027 have risen to $4.27 from $3.56. INDV shares have gained 16.6% year to date.

Indivior Pharmaceuticals’ earnings beat estimates in each of the trailing four quarters, with the average surprise being 65.44%.

The estimate for Immunocore’s 2026 EPS is currently pegged at 6 cents. In the past 60 days, the estimates for its 2027 EPS have increased from 24 cents to 87 cents. IMCR shares have lost 11% year to date.

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 46.66%.

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