About DAYBUE

Maddy, age 20, living with Rett syndrome, with her family

Maddy, age 21,
living with Rett
syndrome, with
her family

An opportunity to add more of their sparkle to the world around us

By sparking meaningful improvements in the signs and symptoms of Rett syndrome, DAYBUE^® can help illuminate more of the loved one you’ve always known was inside. See the results from the clinical study below.

DAYBUE is the first and only FDA-approved treatment for Rett syndrome in adults and children 2 years of age and older. It is not known if DAYBUE is safe and effective in children under 2 years of age. Over 1700 people living with Rett syndrome have started DAYBUE—including people with a variety of Rett symptoms, girls, boys, and adults.

DAYBUE is not a cure for Rett syndrome.

How was DAYBUE studied?

Caregivers and doctors evaluated changes in the signs and symptoms of Rett syndrome in the LAVENDER™ study

Because caregivers possess such a deep knowledge of their loved one, they contributed directly to the evaluation of the overall effectiveness of DAYBUE. Doctors evaluated if patients improved or got worse, while caregivers looked for changes in the signs and symptoms of Rett syndrome.

Icon of two hands being held in the shape of a heart

Caregivers used the Rett Syndrome Behaviour Questionnaire (RSBQ) to evaluate changes in the signs and symptoms of Rett syndrome.

Doctors used the Clinical Global Impression-Improvement (CGI-I) scale to evaluate if Rett symptoms had improved or worsened.

Expand to see study design

The effectiveness and safety of DAYBUE were evaluated in the 12-week LAVENDER clinical study of 187 female patients aged 5 to 20 with Rett syndrome

Breathing

Hand movements or stereotypies

Repetitive behaviors

Nighttime behaviors

Vocalizations

Facial expressions

Eye gaze

Mood

Understanding RSBQ

Caregivers evaluated 45 items on the RSBQ. Each item was scored as not true (0), somewhat or sometimes true (1), or very true or often true (2)
The scores were added up to determine the RSBQ total score across symptoms
Researchers looked at the change in average RSBQ total score from the start of the study to measure how DAYBUE impacted the signs and symptoms of Rett at Week 12 when compared to patients receiving placebo

At 12 weeks, caregivers observed:

At 12 weeks, the group of patients receiving DAYBUE (n=76) saw a decrease of 4.9 in average RSBQ total score from the start of the study when compared with a decrease of 1.7 in the placebo group (n=85), meaning an improvement in Rett symptoms
The difference between the two groups was -3.2. A lower score meant signs and symptoms of Rett syndrome were less severe
Before starting treatment, the average RSBQ total score for the DAYBUE group was 43.7. For the placebo group, the average RSBQ total score before treatment was 44.5
Results varied between patients in the clinical study. The effect of DAYBUE on individual symptoms measured by RSBQ has not been shown. Individual results may vary with DAYBUE

Symptom areas (RSBQ)	Quinn6 years old Taking DAYBUE since 2021	Clare9 years old Taking DAYBUE since 2021	Kate9 years old Taking DAYBUE since 2021	Ellie16 years old Taking DAYBUE since 2020	Maddy21 years old Taking DAYBUE since 2020

Hand movements or stereotypies	More control of hands. Can hold objects longer. Not grasping her body and face as much	Hands are more fluid and open, can hold a fork or cup, taps on fridge when hungry	More purposeful hand use. Able to use a spoon and point at and touch her tablet	Quiet, calmer hands. Can hold a cup, fork and grasp and reach for things	Less aggressive hand movements. More control of hands
Repetitive behaviors	Teeth grinding much improved				Hardly grinds her teeth anymore
Breathing	Less frequent breath holding and less hyperventilating				Fewer “blue spells” (breath holding)
Nighttime behaviors		Less frequent night terrors allow her to sleep better			Fewer night terrors and laughing spells - now family gets more sleep
Vocalizations		Increased nonverbal vocalizations, able to let people know when she wants something		She makes a lot of chatty sounds. Says “fun, funny, and food“	No words, but makes more sounds to respond
Facial expressions					Doesn't stick her tongue out as often
Eye gaze	Can hold her gaze to participate and engage, especially in the classroom	Uses eye gaze more to convey feelings, needs, and wishes. Allows her to show family what she wants for a snack	Able to use her eye-gaze device better to convey wishes	Uses her eyes to say yes or no and to make choices	Makes choices more quickly with her eyes. More of an interest in using her eye-gaze device
Mood	Her moods are more predictable and cries a lot less	Less screaming and tantrums. Able to take an interest in the things around her	More peaceful at home, in school, and in groups	She's able to regulate her emotions a little better. She's happier than she used to be	Mood is better, happier, much less crying for no apparent reason

Important Notes:

In the clinical study, individual response varied. Some patients had minimal to no improvements with DAYBUE
These patients were also receiving other types of therapy, like physical, occupational, or speech therapy
Some of these patients experienced side effects, including diarrhea, behavioral issues, or gas. See the full stories to learn more about their DAYBUE experiences
Always speak with a healthcare provider to learn what to expect when starting DAYBUE, including side effects
The families featured here were compensated for sharing their stories and participating in photo shoots. These stories were created in 2024

Clare, age 8, living with Rett syndrome, with her mom

Learn from caregivers and their individual loved one’s experience with DAYBUE

View DAYBUE stories

Clare, age 9, living with Rett syndrome, with her mom

At 12 weeks, doctors observed:

Significant improvements in the signs and symptoms of Rett syndrome in patients taking DAYBUE vs placebo

The CGI-I (Clinical Global Impression-Improvement) scale was used by doctors to evaluate improvement or worsening of Rett symptoms.

38% of patients (n=77) had improvement in symptoms with DAYBUE vs 15% of patients (n=86) on placebo
- Much improved (13% vs 5% for placebo), minimally improved (25% vs 10%)
61% of patients had no improvements in symptoms with DAYBUE vs 81% of patients taking placebo

Important Note: Because each individual with Rett syndrome is unique—with a unique set of symptoms—improvements with DAYBUE may be different for everyone.

Do you have questions about treatment with DAYBUE?

While treatment with DAYBUE is a decision you and your loved one’s doctor can make, Family Support Educators can help answer your questions about Rett syndrome, comprehensive care, and connecting with other caregivers.

Get connected with a Family Support Educator

Lara, Family Support Educator

Diarrhea:

Diarrhea is a common side effect of DAYBUE that can sometimes be severe. Diarrhea may cause your child to lose too much water from their body (dehydration). Before starting treatment with DAYBUE, stop taking laxatives. Tell your doctor if your child has diarrhea while taking DAYBUE. Your doctor may ask you to increase the amount your child drinks or give antidiarrheal medicine as needed.

Vomiting:

Vomiting is a common side effect of DAYBUE. Sometimes vomit can get into your child's lungs (aspiration), which could cause an infection (aspiration pneumonia). Tell your doctor if they have severe vomiting or if vomiting happens often.

Weight loss:

DAYBUE can cause weight loss. Tell your doctor if you notice your child is losing weight at any time during treatment with DAYBUE.

Common side effects in the 12-week LAVENDER trial

Learn how to help manage possible side effects

Management guidance

The DAYBUE Overview Brochure provides information about DAYBUE clinical trial results and safety info

The DAYBUE Overview Brochure provides information about DAYBUE clinical study results, safety facts, caregiver experiences, and helpful treatment tips.

Download now

The DAYBUE Starting Treatment Discussion Guide for caregivers, a tool you can use to talk to your child’s doctor about DAYBUE

The DAYBUE Treatment Discussion Guide is a tool you can use to talk to your loved one’s doctor about DAYBUE.

Download now

Support by your side

Acadia Connect is a patient and family support program that connects you and your family with educational support and resources throughout the DAYBUE treatment journey.

Call Acadia Connect at 1-844-737-2223, Monday to Friday, 8AM to 8PM ET, to learn more about our individualized support program designed to help meet the needs of your loved one taking DAYBUE.

Learn how we can help

Important Safety Information and Indication

What are the possible side effects of DAYBUE?

Diarrhea: Diarrhea is a common side effect of DAYBUE that can sometimes be severe. Diarrhea may cause you to lose too much water from your body (dehydration). Before starting treatment with DAYBUE, stop taking laxatives. Tell your healthcare provider if you have diarrhea while taking DAYBUE. Your healthcare provider may ask you to increase the amount you drink or take antidiarrheal medicine as needed.
Vomiting: Vomiting is a common side effect of DAYBUE. Sometimes vomit can get into your lungs (aspiration), which could cause an infection (aspiration pneumonia). Tell your healthcare provider if you have severe vomiting or if vomiting happens often.
Weight loss: DAYBUE can cause weight loss. Tell your healthcare provider if you notice you are losing weight at any time during treatment with DAYBUE.
The most common side effects of DAYBUE were diarrhea and vomiting. Other side effects include fever, seizure, anxiety, decreased appetite, tiredness, and the common cold. These are not all the possible side effects of DAYBUE. Tell your healthcare provider if you have any side effects that bother you or do not go away.

What should I tell my healthcare provider before taking DAYBUE?

Before taking DAYBUE, tell your healthcare provider about all of your medical conditions, including if you:

have kidney problems.
are pregnant or plan to become pregnant. It is not known if DAYBUE will harm your unborn baby.
are breastfeeding or plan to breastfeed. It is not known if DAYBUE passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby while taking DAYBUE.

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking DAYBUE with certain medicines may affect how the other medicines work and can cause serious side effects.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088. You can also call Acadia Pharmaceuticals Inc. at 1-844-4ACADIA (1-844-422-2342).

What is DAYBUE?

DAYBUE is a prescription medicine used to treat Rett syndrome in adults and children 2 years of age and older. It is not known if DAYBUE is safe and effective in children under 2 years of age.

DAYBUE is available as an oral solution (200 mg/mL).

The risk information provided here is not comprehensive. To learn more, talk with your healthcare provider and read the fullPrescribing Information,Patient Information, also available at DAYBUE.com.