Preventing viral relapse with prophylactic tenofovir in hepatitis B carriers receiving chemotherapy: a phase IV randomized study in Taiwan

This study aimed to compare the efficacy of shorter vs. longer tenofovir disoproxil fumarate (TDF) prophylaxis in preventing hepatitis B virus (HBV) relapse in cancer patients with chronic hepatitis B (CHB) undergoing chemotherapy. This phase IV, prospective randomized trial enrolled cancer patients with CHB from 2014 to 2019 in Taiwan. Included patients were randomized to receive either 24- (Arm A) or 48-week (Arm B) post-chemotherapy TDF and compared for cumulative incidence of virological and clinical relapse. Logistic regressions were conducted to determine the factors associated with HBV relapse. One hundred patients were randomized, and 41 patients in Arm A and 46 in Arm B completed the TDF treatment. No significant difference was found in cumulative incidence of virological relapse (Arm A: 94.4%, Arm B: 93.1%, p = 0.110) or clinical relapse among patients with baseline HBV DNA > 2000 IU/mL (Arm A: 38.9%, Arm B: 26.7%, p = 0.420) between the two arms. High baseline HBV DNA ≥ 10,000 IU/mL (OR = 51.22) and HBsAg ≥ 1000 IU/mL (OR = 8.64) were independently associated with an increased virological relapse. Alanine aminotransferase (ALT), serum phosphorus, vitamin D, and estimated glomerular filtration rate (eGFR) remained stable throughout the study. The 24-week preventative TDF has comparable efficacy to the 48-week treatment in virologic and clinical relapse. High baseline HBsAg or HBV DNA is associated with a higher risk of HBV relapse. These findings imply a 24-week duration of TDF treatment with a close monitor for patients with a high baseline viral load. Hepatitis B virus infection is a prominent cause of liver cancer and chronic liver disease and affected millions of people worldwide. When HBV-infected people are exposed to immunosuppressive medication or chemotherapy for cancer, the chance of HBV reactivation rises considerably. This trial showed 24-week tenofovir disoproxil fumarate (TDF) may be sufficient for preventing HBV relapse in cancer patients receiving chemotherapy. NCT02081469.