Summary

This phase III trial studies the effect of tenofovir alafenamide in preventing liver complications in patients with current or past hepatitis B virus (HBV) who are receiving anti-cancer therapy for solid tumors. People with chronic or past HBV who are undergoing therapy for cancer are at an increased risk for changes in the liver which could be minor or severe. Tenofovir alafenamide is a drug that acts against infections caused by HBV and may help reduce the chance that HBV gets worse or comes back in patients receiving anti-cancer therapy for solid tumors.

Objectives

PRIMARY OBJECTIVES:
I. To compare the effect of prophylactic anti-HBV therapy versus upon indication anti-HBV therapy on time-to-adverse liver outcomes of liver failure or liver-related death in patients with chronic HBV infection (hepatitis B surface antigen positive [HBsAg+] and antibody to hepatitis B core antigen positive [anti-HBc+]) receiving anti-cancer therapy for solid tumors.
II. To compare the effect of upon indication anti-HBV therapy versus usual care on time-to-adverse liver outcomes of liver failure or liver-related death in patients with past HBV infection (hepatitis B surface antigen negative [HBsAg-] and anti-HBc+) receiving anti-cancer therapy for solid tumors.

SECONDARY OBJECTIVES:
I. Using time-to-event analysis, to compare the effect of anti-HBV therapy versus upon indication anti-HBV therapy on HBV reactivation, on the combined endpoint of adverse liver outcomes (liver failure or liver-related death) and HBV reactivation, and on HBV flare by arm in patients with chronic HBV infection receiving anti-cancer therapy for solid tumors.
II. Using time-to-event analysis, to compare the effect of upon indication anti-HBV therapy versus usual care on HBV reactivation, on the combined endpoint of adverse liver outcomes (liver failure or liver-related death) and HBV reactivation, and on HBV flare by arm in patients with past HBV infection receiving anti-cancer therapy for solid tumors.

TRANSLATIONAL OBJECTIVES:
I. To compare baseline and changes in overall immune status and HBV-specific immune response in patients with solid tumors and chronic or past HBV infection receiving anti-cancer therapy, and to compare the differences in these immune responses by HBV reactivation status.
II. To identify demographic and clinical predictors and correlative immunologic biomarkers of HBV reactivation after receipt of anti-cancer therapy in patients with solid tumors and chronic or past HBV infection.

OUTLINE: Patients are randomized to 1 of 3 groups.

GROUP A (Cohorts 1a & 2a): Patients receive tenofovir alafenamide (TAF) orally (PO) once daily (QD) or tenofovir disoproxil fumarate (TDF) PO QD or entecavir PO QD immediately or within 42 days after initial dose of chemotherapy. Treatment continues for up to 6 months after the last dose of chemotherapy or a maximum of 24 months in the absence of disease progression or unacceptable toxicity.

GROUP B (Cohorts 1b & 2b): Patients receive TAF PO QD or TDF PO QD or entecavir PO QD after HBV reactivation during chemotherapy. Treatment continues for up to 6 months after the last dose of chemotherapy or a maximum of 24 months in the absence of disease progression or unacceptable toxicity.

GROUP C (Cohort 3): Patients receive TAF PO QD or TDF PO QD or entecavir PO QD at the discretion of the physician during usual care. Treatment continues for up to 6 months after discontinuation of usual care or a maximum of 24 months in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up every 4 weeks for up to 24 months.