Daybue is a prescription medicine used to treat a rare, genetic neurological disorder called Rett syndrome.

Daybue contains trofinetide, a synthetic version of a naturally occurring molecule known as the tripeptide glycine-proline-glutamate (GPE). The exact way by which Daybue works to treat Rett syndrome is not known, but it is thought to reduce inflammation and support synaptic function in the central nervous system.

What is Daybue used to treat?

Daybue is used to treat Rett syndrome in adults and children 2 years of age and older.

Rett syndrome is a rare, neurological disorder caused by mutations on the X chromosome on a gene called MECP2. It occurs primarily in females with symptoms usually presenting between six to 18 months of age.

Rett syndrome causes problems in brain function. Children with Rett syndrome experience loss of fine motor skills, impaired gross motor skills, and loss of communication skills (including eye contact). Symptoms may also include seizures, disorganized breathing patterns, scoliosis, and sleep disturbances.

It is not known if this medicine is safe and effective in children under 2 years of age.

Daybue is usually taken twice daily, morning and evening, with or without food. Take the medicine exactly as your healthcare provider tells you to take it.

If you take laxatives, stop taking them before starting treatment.

Your healthcare provider may change your dose or stop treatment if needed.

Your pharmacist should provide an oral syringe or dosing cup that is needed to measure your prescribed dose. Do not use a household measuring cup.

Daybue oral solution may be taken by mouth or given through a gastrostomy (G) tube. If the oral solution is given through a gastrojujenal (GJ) tube, the G-port must be used.

Throw away any unused oral solution after 14 days of first opening the bottle.

If you vomit after taking a dose, do not take another dose to make up for that dose. Wait and take the next dose at your usual time.

If you miss a dose, skip that dose and take your next dose at your usual time. Do not take 2 doses to make up the missed dose.

Usual Adult and Pediatric Dose for Rett Syndrome:

Daybue is supplied as a pink to red, strawberry flavored oral solution containing 200 mg per mL.

Comments:
- can be given orally or via gastrostomy (G) tube; doses administered via gastrojejunal (GJ) tubes must be administered through the G-port.

Use:
- treatment of Rett syndrome in adults and pediatric patients 2 years of age and older.

Before you start treatment, tell your healthcare provider about all of your medical conditions, including if you:

• have kidney problems.

Pregnancy

Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known if Daybue will harm your unborn baby.

Breastfeeding

Tell your healthcare provider if you 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 during treatment.

Daybue may cause side effects, including:

• Diarrhea. Diarrhea is a common side effect and it can sometimes be severe. Diarrhea may cause you to lose too much water from your body (dehydration). Tell your healthcare provider if you have diarrhea. Your healthcare provider may ask you to increase the amount you drink or take anti-diarrheal medicine as needed.
• Weight loss. Daybue can cause weight loss. Tell your healthcare provider if you notice you are losing weight at any time during treatment.

The most common side effects include diarrhea and vomiting.

These are not all the possible side effects.Tell your healthcare provider if you have any side effects that bother you or do not go away. For more information, ask your healthcare provider or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

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 the way other medicines work and can cause serious side effects.

Especially tell your doctor if you take laxatives. Daybue can cause diarrhea, so you should stop taking laxatives before you start treatment.

Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.