Name: Aqneursa (levacetylleucine) in Ataxia-telangiectasia: Heterogeneity of treatment effect
Published: 2026-10-02T18:22:10-04:00

Predefined subgroup analyses of the primary endpoint in IB1001-303

“For the primary and each secondary endpoint, there were separate evaluations within key subgroups predefined in the statistical analysis plan (the trial was not powered for conclusions in these subgroups).” (opens the source at this quote in a new tab)
“Figure 3B displays results for the primary SARA endpoint in the predefined subgroups showing 95% CIs. There is no evidence of heterogeneity in treatment effect across subgroups that would suggest a differential treatment effect across the population. Instead, across all subgroups, there were consistent improvements with levacetylleucine versus placebo.” (opens the source at this quote in a new tab)
“Subgroup analysis showed consistent benefit across all demographics of patients, irrespective of age (paediatric vs adult), age at disease onset, or gender.” (opens the source at this quote in a new tab)
“Subgroup analyses showed that the improvement in neurological status was observed across all demographics of patients (age of neurological disease onset, disease severity, and gender, etc), indicating that the treatment might be applicable for all patients with ataxia-telangiectasia.” (opens the source at this quote in a new tab)

Size of the age, age-at-diagnosis, and dose subgroups in IB1001-303

Subgroup	Participants (n=73)
Paediatric (<18 years)	“47 (64%)”
Adult (≥18 years)	“26 (36%)”
Age at diagnosis: early-infantile (<2 years)	“51 (70%)”
Age at diagnosis: late-infantile (2 to <6 years)	“16 (22%)”
Age at diagnosis: juvenile (6 to <15 years)	“3 (4%)”
Age at diagnosis: adolescent or adult (≥15 years)	“3 (4%)”
Weight 15 to <25 kg (2 g per day)	“18 (25%)”
Weight 25 to <35 kg (3 g per day)	“17 (23%)”
Weight ≥35 kg (4 g per day)	“38 (52%)”

Randomization without stratification by age

“As the trial was a crossover design, in which each patient received levacetylleucine and placebo and therefore served as their own control, no stratification by age was done.” (opens the source at this quote in a new tab)

Company statements on subgroup consistency

“Subgroup analysis of the primary and secondary endpoints demonstrated consistent clinical effects across all demographics (age, gender, disease severity, age of symptom onset, etc.).” (opens the source at this quote in a new tab)

“Improvement was consistent across secondary endpoints and prespecified subgroups, including pediatric and adult patients, with no evidence of heterogeneity in treatment effect across the population.” (opens the source at this quote in a new tab)

Classic versus variant ataxia-telangiectasia

No evidence found.

Pediatric, low body weight, and geriatric populations in the label

“The safety and effectiveness of AQNEURSA for the treatment of ataxia in patients with A-T have been established in 47 pediatric patients weighing ≥ 15 kg in Trial 2” (opens the prescribing information at this quote)
“The safety and effectiveness of AQNEURSA have not been established in pediatric patients weighing <15 kg.” (opens the prescribing information at this quote)
“Clinical studies of AQNEURSA did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently from younger adult patients.” (opens the prescribing information at this quote)

Exposure and response

“A relationship was not observed between increasing levacetylleucine exposure and clinical efficacy.” (opens the prescribing information at this quote)

Race and ethnicity of the trial population

“Fourth, most patients in this trial were White and of North American or European descent, and data on patients of other ethnicities were scarce or absent.” (opens the source at this quote in a new tab)