Date of report 23 Dec 2020

Reported case interaction between
Darunavir and Enzalutamide

A 58-year-old male, HIV positive since in 1988 with a history of multiple ART regimens and high level resistance to all NRTIs, all first-generation NNRTIs and PIs (except DRV), was diagnosed with protaste cancer with bone metastases. The patient required a treatment with enzalutamide, a potent CYP3A4 inducer and moderate inducer. At the time of the oncological diagnosis, the patient was treated with TDF (300 mg QD), emtricitabine (200 mg QD), darunavir/r (600/100 mg BID), raltegravir (400 mg QD), etravirine (200 mg QD). The drug interaction with enzalutamide was successfully managed by increasing ritonavir and etravirine doses and by replacing raltegravir with dolutegravir. The antiretoviral regimen in presence of enzalutamide was darunavir/r (600/200 mg BID), dolutegravir (50 mg BID), etravirine (200 mg BID), TDF (300 mg QD), emtricitabine (200 mg QD). TDM showed that ARV drug levels after adjustment were comparable to those in absence of enzalutamide. After 7 months of concomitant therapy with enzalutamide, prostate-specific antigen improved from 1.1 to 0.1 ng/mL. At more than 2.5 years follow-up, the patient remains virologically suppressed on the same medications. This case was published by Nhean S et al. AIDS 2018.