FDA

Daybue Stix

Approved 11 Dec 2025OralSolution

The FDA lists this product in 5 strengths and forms.

Indications

DAYBUE and DAYBUE STIX are indicated for the treatment of Rett syndrome in adults and pediatric patients 2 years of age and older. DAYBUE and DAYBUE STIX are indicated for the treatment of Rett syndrome in adults and pediatric patients 2 years of age and older. ( 1 )

Contraindications

None. None. ( 4 )

Warnings and precautions

Diarrhea: Most patients experience diarrhea during treatment with DAYBUE. Advise patients to stop laxatives before starting DAYBUE or DAYBUE STIX. If diarrhea occurs, patients should start antidiarrheal treatment, increase oral fluids, and notify their healthcare provider. Interrupt, reduce dose, or discontinue DAYBUE or DAYBUE STIX if severe diarrhea occurs or if dehydration is suspected. ( 2.4 , 5.1 ) Weight Loss: Weight loss may occur in patients treated with DAYBUE or DAYBUE STIX.

Monitor weight and interrupt, reduce dose, or discontinue DAYBUE or DAYBUE STIX if significant weight loss occurs. ( 2.4 , 5.2 ) Vomiting: Aspiration and aspiration pneumonia have occurred after vomiting in patients treated with DAYBUE. Interrupt, reduce dose, or discontinue DAYBUE or DAYBUE STIX if vomiting is severe or occurs despite medical management. ( 2.5 , 5.3 )

5.1Diarrhea In Study

1 [see Clinical Studies (14) ] and in long-term studies, 85% of patients treated with DAYBUE experienced diarrhea. In those treated with DAYBUE, 49% either had persistent diarrhea or recurrence after resolution despite dose interruptions, reductions, or concomitant antidiarrheal therapy. Diarrhea severity was of mild or moderate severity in 96% of cases. In Study 1, antidiarrheal medication was used in 51% of patients treated with DAYBUE.

Advise patients to stop laxatives before starting DAYBUE or DAYBUE STIX. If diarrhea occurs, patients should notify their healthcare provider, consider starting antidiarrheal treatment, and monitor hydration status and increase oral fluids, if needed. Interrupt, reduce dose, or discontinue DAYBUE or DAYBUE STIX if severe diarrhea occurs or if dehydration is suspected [see Dosage and Administration (2.4) ] .

5.2Weight Loss In Study 1, 12%

of patients treated with DAYBUE experienced weight loss of greater than 7% from baseline, compared to 4% of patients who received placebo. In long-term studies, 2.2% of patients discontinued treatment with DAYBUE due to weight loss. Monitor weight and interrupt, reduce dose, or discontinue DAYBUE or DAYBUE STIX if significant weight loss occurs [see Dosage and Administration (2.4) ] .

At a glance

Brand name: Daybue Stix
Active substance: trofinetide
Route: Oral
Dosage form: Solution
Applicant: Acadia Pharms Inc
Status: Prescription
FDA approval: 11 Dec 2025
Application: NDA219884-004

Warnings and precautions

5.1Diarrhea In Study

5.2Weight Loss In Study 1, 12%

Adverse reactions

The following clinically significant adverse reactions are described elsewhere in labeling: Diarrhea [see Warnings and Precautions (5.1) ] Weight Loss [see Warnings and Precautions (5.2) ] Vomiting [see Warnings and Precautions (5.3) ] The most common adverse reactions (that occurred in at least 10% of DAYBUE-treated patients and at least 2% greater than in placebo) were diarrhea and vomiting. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Acadia Pharmaceuticals Inc. at 1-844-422-2342 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In controlled and uncontrolled trials in patients with Rett syndrome, 260 patients ages 2 to 40 years were treated with DAYBUE, including 112 patients treated for more than 6 months, 92 patients treated for more than 1 year, and 44 patients treated for more than 2 years.

The safety of DAYBUE STIX has been established from an adequate, well-controlled study, and open-label studies of DAYBUE [see Clinical Studies (14) ] . Below is a display of the adverse reactions of DAYBUE in these studies. Adult and Pediatric Patients with Rett Syndrome 5 Years of Age and Older The safety of DAYBUE was evaluated in a randomized, double-blind, placebo-controlled, 12-week study of patients with Rett syndrome (Study 1) [see Clinical Studies (14) ] .

In Study 1, 93 patients received DAYBUE and 94 patients received placebo. All patients were female, 92% were White, and the mean age was 11 years (range 5 to 20 years). Adverse Reactions Leading to Discontinuation of Treatment Eighteen patients (19%) receiving DAYBUE had adverse reactions that led to withdrawal from the study. The most common adverse reaction leading to discontinuation of treatment with DAYBUE was diarrhea (15%).

Common Adverse Reactions Adverse reactions that occurred in Study 1 in at least 5% of patients treated with DAYBUE and were at least 2% more frequent than in patients on placebo are presented in Table 5 . Table 5 Adverse Reactions in at Least 5% of Patients Treated with DAYBUE and at Least 2% Greater than Placebo in Study 1 Adverse Reaction DAYBUE (N=93) % Placebo (N=94) % Diarrhea 82 20 Vomiting 29 12 Fever 9 4 Seizure 9 6 Anxiety 8 1 Decreased appetite 8 2 Fatigue 8 2 Nasopharyngitis 5 1 Pediatric Patients with Rett Syndrome 2 to 4 Years of Age In an open-label study in pediatric patients 2 to 4 years of age with Rett syndrome (N=15), a total of 13 patients received DAYBUE for at least 12 weeks and 10 patients received DAYBUE for at least 12 months.

Adverse reactions in pediatric patients 2 to 4 years of age treated with DAYBUE were similar to those reported in adult and pediatric patients 5 years of age and older with Rett syndrome in Study 1.

6.2Postmarketing Experience

The following adverse reactions have been identified during postapproval use of DAYBUE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Aspiration and aspiration pneumonia secondary to vomiting [see Warnings and Precautions (5.3) ] .

Daybue Stix

Indications

Contraindications

Warnings and precautions

5.1Diarrhea In Study

5.2Weight Loss In Study 1, 12%

At a glance

Two medicines in one question?

Daybue Stix

Indications

Contraindications

Warnings and precautions

5.1Diarrhea In Study

5.2Weight Loss In Study 1, 12%

At a glance

Two medicines in one question?

5.3Vomiting In Study

Interactions

7.1Effect of

Pregnancy and breastfeeding

8.1Pregnancy Risk Summary

Adverse reactions

6.1Clinical Trials Experience

6.2Postmarketing Experience

Composition

Strengths and forms

Official product information