Name: Aqneursa (levacetylleucine) in Ataxia-telangiectasia: Effects of levacetylleucine on other drugs
Published: 2026-10-02T18:22:10-04:00

Product information and disease description Product description Product information Drug/Drug, drug/disease interactions

Effects of levacetylleucine on other drugs

5 evidence topics · 4 sources

P-glycoprotein transporter substrates

“Monitor more frequently for P-gp substrate related adverse reactions when used concomitantly with AQNEURSA.” (opens the prescribing information at this quote)
“Levacetylleucine inhibits P-gp” (opens the prescribing information at this quote)
“However, the clinical significance of this finding has not been fully characterized.” (opens the prescribing information at this quote)

“Patients receiving P-glycoprotein (P-gp) substrates should be monitored more frequently for related adverse reactions when used with Aqneursa.” (opens the source at this quote in a new tab)

In vitro enzyme and transporter studies: prescribing information

Study	Prescribing information
Cytochrome P450 inhibition and induction	“Levacetylleucine does not inhibit CYP 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4 and does not induce CYP 1A2, 2B6, or 3A4.”
Transporter inhibition	“Levacetylleucine inhibits P-gp, BCRP, bile salt export pump (BSEP), OAT1 and OAT3, but does not inhibit organic anion transporting polypeptide (OATP)1B1 and OATP1B3.”

Substrates of P-gp, BCRP, BSEP, and MATE transporters: European Union labeling

“Levacetylleucine may be an inhibitor of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) or bile salt export pump (BSEP) (see section 5.2). The relevance to humans is uncertain.” (opens the source at this quote in a new tab)
“A potential interaction of levacetylleucine with other medicinal products that are substrates of P-gp (e.g. digoxin, dabigatran, loperamide, irinotecan, doxorubicin, vinblastine, paclitaxel, fexofenadine, seliciclib, quinidine, talinolol), BCRP (e.g. sulfasalazine, rosuvastatin) or BSEP cannot be excluded.” (opens the source at this quote in a new tab)
“Caution should be exercised when levacetylleucine is co-administered with BSEP substrates.” (opens the source at this quote in a new tab)
“The potential inhibitory effect of levacetylleucine on multidrug and toxin extrusion proteins (MATE) transporters is unknown; therefore, caution is advised when co-administering levacetylleucine with substrates of MATE transporters.” (opens the source at this quote in a new tab)
“Levacetylleucine is a substrate and an in vitro inhibitor of organic anion transporter (OAT)1 and OAT3. The likelihood of clinically meaningful drug interactions is considered low.” (opens the source at this quote in a new tab)

Inhibitory concentrations and the planned clinical interaction study

“Inhibition towards efflux transporters MDR1, BCRP and BSEP by levacetylleucine was observed and IC50 values were 227 (MDR1), 491 (BCRP) and 408 (BSEP) μg/mL equal to 1.31 (MDR1), 2.83 (BCRP) and 2.36 (BSEP) mM.” (opens the source at this quote in a new tab)
“Therefore, a clinical DDI study involving P-gp and BCRP substrates is warranted to evaluate the extent of levacetylleucine's inhibitory effect on these transporters.” (opens the source at this quote in a new tab)
“The Applicant committed to conduct a DDI study to evaluate P-gp and BCRP inhibition.” (opens the source at this quote in a new tab)

Cytochrome P450 substrates: European assessment

“These finding suggest that the DDI potential between levacetylleucine and the tested CYPs substrates could be ruled out at both systemic and intestinal level.” (opens the source at this quote in a new tab)
“From a clinical perspective, these findings suggest that there is no risk of CYP enzyme induction-related DDI.” (opens the source at this quote in a new tab)