Acetyl-DL-leucine case series

13 evidence topics · 2 sources

Objective

Hypothesis

“As cerebellar symptoms of storage diseases were improved by acetyl-DL-leucine (ADLL), the authors hypothesized a symptomatic and disease-modifying effect in AT upon supplementation with ADLL.” (opens the source at this quote in a new tab)

Location and study date

Study design

Uncontrolled case series with assessments before and during treatment

“Six patients were treated with ADLL 3 g/day for 1 week followed by 5g/day for 3 weeks to 1 year.” (opens the source at this quote in a new tab)
“Measurements took place at baseline, at 1 month of therapy in 5 patients, and after 6 and 12 months in 1 patient.” (opens the source at this quote in a new tab)

Eligibility criteria

Treatment

Acetyl-DL-leucine dose and duration

“Six patients were treated with ADLL 3 g/day for 1 week followed by 5g/day for 3 weeks to 1 year.” (opens the source at this quote in a new tab)

Study outcomes

Rationale for using SARA total score as an efficacy outcome

Ataxia scales and video-oculography

“Cerebellar ataxia was evaluated by validated scales.” (opens the source at this quote in a new tab)
“Gaze-holding, saccades and smooth pursuit were examined by video-oculography.” (opens the source at this quote in a new tab)

Statistical analysis description

Number of participants (Planned and analyzed)

Participants treated and assessed

Population	Participants
Treated with acetyl-DL-leucine	“Six patients”
Assessed at 1 month of therapy	“5 patients”
Assessed after 6 and 12 months	“1 patient”

Description of analysis sets

Results

Participant disposition

Follow-up assessments

“Measurements took place at baseline, at 1 month of therapy in 5 patients, and after 6 and 12 months in 1 patient.” (opens the source at this quote in a new tab)

Baseline characteristics

Baseline SARA score and oculomotor findings

Characteristic	Value
SARA at baseline, mean (SD, minimum to maximum)	“22.1 (5.88, 11-28.5)”
Slow-phase velocity of downbeat nystagmus at baseline	“5.57°/s (1.8, 3.53-6.99)”

“All patients demonstrated gaze-holding deficits; 3 patients had central-position downbeat-nystagmus.” (opens the source at this quote in a new tab)

Efficacy results

SARA total score after 1 month

“The Scale for Assessment and Rating of Ataxia changed from the baseline, mean, (SD, min-max) of 22.1 (5.88, 11-28.5) to 18 points (5.39, 8.5-23.5) after 1 month on medication (P = .0028).” (opens the source at this quote in a new tab)

Downbeat nystagmus after 1 month

“Mean slow-phase velocity of this nystagmus with the gaze straight-ahead changed from 5.57°/s (1.8, 3.53-6.99) to 4.7°/s (0.79, 3.97-5.56) after 1 month on treatment (1.35, -2.56-4.17) (P = .046).” (opens the source at this quote in a new tab)

Authors' interpretation

“ADLL may improve ataxia and ocular stability in AT patients, while the molecular basis still remains to be elucidated.” (opens the source at this quote in a new tab)

Health-related quality of life and patient-reported outcomes

Safety results

Study limitations

Summary

The series included six participants treated open label with the racemate acetyl-DL-leucine and had no control group. Follow-up measurements were made at 1 month in 5 participants and at 6 and 12 months in 1 participant. The abstract reports no adverse event or quality-of-life results. A 2026 systematic review rated the quality of the study as low on the National Institutes of Health tool for studies without a control group and listed limited duration and incomplete assessment in some cases as its limitations. The evidence quoted here comes from the article's abstract.

Quality assessment in a systematic review

Item	Assessment
Quality	“Low”
Limitations	“Limited duration and incomplete assessment in some cases”

“Common methodological limitations included small sample sizes, absence of control groups, lack of blinding, and short follow‐up duration.” (opens the source at this quote in a new tab)

Authors' reference to a subsequent trial

“A multicentric, rater-blinded, phase II trial currently investigates the effects of acetyl-L-leucine in AT (NCT03759678).” (opens the source at this quote in a new tab)