Safety, Tolerability, and Outcomes of Tafamidis for the Treatment of Acquired Amyloid Neuropathy in Domino Liver Transplant Recipients

Introduction: Acquired amyloid neuropathy is an iatrogenic disease that appears years after a domino liver transplant. The objectives of our study are to analyze the efficacy and tolerability of tafamidis for the treatment of acquired amyloid neuropathy in domino liver transplant recipients. This post-authorization, prospective, longitudinal study included seven domino liver transplant recipients with acquired amyloid neuropathy who received treatment with tafamidis for 18 months.

Methods: The primary endpoints were the response rate, defined as those patients with an increase of < 2 points on the Neurological Impairment Score (NIS) from baseline, and the change in the NIS score from baseline. Secondary endpoints included the Quantitative Sensory Test, 10-m walk test, quality of life (Norfolk), and disability (Rasch-built Overall Disability Scale). As safety parameters, the evidence of graft rejection, changes in immunosuppressive trough levels and changes in antiviral and allogeneic cellular immunity before and 12 months after tafamidis treatment were also assessed.

Results: Six patients (85.7%) had responded at 18-months. Compared to baseline, we observed non-statistically significant improvement in mean NIS score at 6 months (- 2.54 points, CI - 5.92 to 0.84), 12 months (- 3.25 points; CI - 6.63 to 0.13), and 18 months (- 2.35 points; CI - 5.74 to 1.02). Changes in the Quantitative Sensory Test, 10-m walk tests and the quality of life and disability questionnaires were not statistically significant. The use of tafamidis did not induce relevant side effects or drug interactions. Also, no acute rejections events nor changes in functional adaptive immunity were observed.

Conclusion: Our study supports the safety and tolerability of tafamidis for the treatment of acquired amyloid neuropathy in domino liver transplant recipients. Tafamidis shows promise as a useful treatment in the clinical management of these patients. Future randomized placebo-controlled clinical trials with longer follow-up durations are needed.