Clinical experience using trofinetide in Rett syndrome and related MECP2 diagnosis at the children's hospital of Philadelphia post approval.

Prange EO, Fleysh D, Reddy K, Dubbs H, Marsh ED

Frontiers in neurology23 Apr 2026

PMID42111068PMCIDPMC13149144DOI10.3389/fneur.2026.1776146PepBankPUB-42111068

Summary

IntroductionRett syndrome (RTT) is a rare neurodevelopmental disorder primarily caused by pathogenic variants in the MECP2 gene. Trofinetide (Daybue) became the first FDA-approved medication for RTT in March 2023. This study evaluates the real-world effectiveness and side effect profile of Trofinetide in 55 individuals (50 females, 5 males) with RTT or MECP2-related neurodevelopmental disorders over a 12-month period.MethodsData was collected through clinic assessments and caregiver reports.ResultsResults demonstrated that 75.9% of individuals experienced some improvement in RTT symptoms by caregiver report, particularly in engagement, communication, and motor skills. The side effect profile was better than the phase 3 trials with only 48.1% reporting diarrhea and 16.7% experiencing vomiting.DiscussionOverall, the findings support the effectiveness of trofinetide in the RTT population and suggests potential effectiveness in the broader MECP2 population including males and those with atypical presentations. The data highlights the need for further work to determine long-term benefits in the full spectrum of MECP2 related disorders. Finally, the study highlights the importance of titration, individualized dosing and side effect management to improve retention and outcomes.

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study3

3 results from studies that gave the peptide. 3 results from people.

01HumanObservational studyEfficacy outcome
In individuals with RTT or MECP2-related disorders receiving trofinetide, caregivers reported some symptom improvement in 75.9%.
In plain wordsCaregivers reported symptom improvement in 75.9% of individuals with RTT or MECP2-related disorders receiving trofinetide.
Peptide
Trofinetide
Outcome
Not applicableCaregiver-reported symptom improvement
Study
n = 55
Outcome group
RTT symptoms · Nervous system and cognition
Studied dose
Dose not stated
Measurements
Symptom improvement
75.9%
caregiver report
Source sentences
Summary
Results demonstrated that 75.9% of individuals experienced some improvement in RTT symptoms by caregiver report, particularly in engagement, communication, and motor skills.
2 context sentences(design, population, supporting numbers)
Summary · context
This study evaluates the real-world effectiveness and side effect profile of Trofinetide in 55 individuals (50 females, 5 males) with RTT or MECP2-related neurodevelopmental disorders over a 12-month period.
Summary · context
Data was collected through clinic assessments and caregiver reports.
Show in the study text Report a problemFND-4211106801
02HumanObservational studySafety outcome
In individuals with RTT or MECP2-related disorders receiving trofinetide, 48.1% reported diarrhea.
In plain wordsAmong individuals with RTT or MECP2-related disorders receiving trofinetide, 48.1% reported diarrhea.
Peptide
Trofinetide
Outcome
Not applicableDiarrhea
Study
n = 55
Outcome group
Gastrointestinal adverse events · Gastrointestinal
Studied dose
Dose not stated
Measurements
Diarrhea
48.1%
reported result
Source sentences
Summary
The side effect profile was better than the phase 3 trials with only 48.1% reporting diarrhea and 16.7% experiencing vomiting.
2 context sentences(design, population, supporting numbers)
Summary · context
This study evaluates the real-world effectiveness and side effect profile of Trofinetide in 55 individuals (50 females, 5 males) with RTT or MECP2-related neurodevelopmental disorders over a 12-month period.
Summary · context
Data was collected through clinic assessments and caregiver reports.
Show in the study text Report a problemFND-4211106802
03HumanObservational studySafety outcome
In individuals with RTT or MECP2-related disorders receiving trofinetide, 16.7% experienced vomiting.
In plain wordsAmong individuals with RTT or MECP2-related disorders receiving trofinetide, 16.7% experienced vomiting.
Peptide
Trofinetide
Outcome
Not applicableVomiting
Study
n = 55
Outcome group
Gastrointestinal adverse events · Gastrointestinal
Studied dose
Dose not stated
Measurements
Vomiting
16.7%
reported result
Source sentences
Summary
The side effect profile was better than the phase 3 trials with only 48.1% reporting diarrhea and 16.7% experiencing vomiting.
2 context sentences(design, population, supporting numbers)
Summary · context
This study evaluates the real-world effectiveness and side effect profile of Trofinetide in 55 individuals (50 females, 5 males) with RTT or MECP2-related neurodevelopmental disorders over a 12-month period.
Summary · context
Data was collected through clinic assessments and caregiver reports.
Show in the study text Report a problemFND-4211106803

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Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
28 Oct 2026, 02:03 UTC
Study results updated
Version 1
27 Oct 2026, 16:37 UTC
First added · source update from Europe PMC

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