Dosing, Safety, and Tolerability of Extended-Release Tacrolimus in Pediatric and Young Adult Solid Organ Transplant Recipients.

BACKGROUND

Complicated immunosuppression regimens can contribute to non-adherence in pediatric solid organ transplant (SOT) recipients. Once-daily tacrolimus formulations, such as LCP-tacrolimus (LCPT), may help simplify dosing, but pediatric data on dosing, safety, and early tolerability are limited.

METHODS

We conducted a single center retrospective cohort study of SOT recipients prescribed LCPT from December 2016 to July 2024 at our institution. LCPT:IR-Tac daily dosing ratios were calculated. The frequency of laboratory-associated adverse events (AE) and of new patient-reported adverse events in the first 90 days were collected and compared across pediatric- and adult-aged SOT recipients.

RESULTS

Ninety-one SOT recipients were prescribed LCPT at a median age of 16.8 years (range 8.4-24.1) and 75 months after transplant (range 0.25-217). Among 53 patients who were therapeutic on both IR-Tac and LCPT, the median daily dosing ratio of LCPT:IR-Tac was 0.75 (range 0.33-1.5) for pediatric patients and 0.75 (IQR: 0.46-1.33) for adults. Eleven (5 patient-reported and 6 laboratory) AEs were identified, none of which resulted in cessation of LCPT therapy. There were no significant differences in the frequency of AEs between children and adults.

CONCLUSIONS

LCPT was well tolerated and typically required about a 25% dose reduction compared with IR-tacrolimus, though conversion ratios varied widely. These findings offer practical guidance for LCPT dosing in pediatric transplant care and highlight the need for individualized titration and monitoring.