Efficacy, Tolerance, and Plasma Levels of Abiraterone and Its Main Metabolites in a Patient With Metastatic Castration-resistant Prostate Cancer With a Hepatic Transplant

Clinical Practice Points

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Abiraterone acetate, which is metabolized in the liver, is a well-established treatment option for patients with metastatic castration-resistant prostate cancer. The impact of hepatic impairment on exposure to abiraterone was well-studied during registration studies, and abiraterone acetate is contraindicated for patients with severe hepatic impairment. Patients with a liver transplant are prone to impaired liver functions and use medication that may affect drug metabolism. However, no efficacy, tolerance, and pharmacokinetic data have been published on abiraterone treatment in patients who have undergone liver transplants.

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In this case report, we established plasma concentrations of abiraterone and its major metabolites, Δ(4)-abiraterone, abiraterone N-oxide sulfate, and abiraterone sulfate, in a patient with metastatic castration-resistant prostate cancer with a hepatic transplant who was treated with abiraterone in a reduced dose of 500 mg daily.

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Treatment was effective and well-tolerated, and plasma concentrations were above the suggested trough concentration threshold of 8.4 ng/mL. Moreover, the exposure to immunosuppressive drugs was within expected therapeutic ranges.

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From this case, we conclude that abiraterone actetate seems to be a feasible and safe treatment strategy for patients with a hepatic transplant. However, further clinical studies should be performed in order to confirm these findings.