Patients randomized to the experimental arm will receive ursodeoxycholic acid (UDCA) as initial treatment for hepatitis. After evaluation of the primary endpoint at Day 21, UDCA treatment will be continued for a total duration of 6 months. In case of lack of response to UDCA, patients will continue UDCA and will additionally receive corticosteroids which represent the reference treatment.

Patients randomized to the control arm will receive the reference treatment, corticosteroids. Corticosteroids will be given at a dose of 0.5-1 mg/kg/day for 21 days, followed by tapering in weekly steps of 10 mg until treatment discontinuation. At Day 21, in case of lack of treatment response, defined as no decrease of alkaline phosphatase and/or gamma-glutamyl transferase levels of at least 25% compared with baseline, corticosteroid tapering will continue, and ursodeoxycholic acid (UDCA) will be added at a dose of 13-15 mg/kg/day.

Ursodeoxycholic acid (UDCA) will be administered orally at an initial dose of 13-15 mg/kg/day, divided into two daily doses. After assessment of the primary endpoint at Day 21, UDCA will be continued for a total treatment duration of 6 months. In case of absence of treatment response, defined as no decrease of alkaline phosphatase and/or gamma-glutamyl transferase levels of at least 25% compared with baseline, corticosteroids which represent the reference treatment, will be added at a dose of 0.5-1 mg/kg.

The rate of patients showing an improvement of at least 25% in liver function tests (alkaline phosphatase and/or gamma-GT) on Day 21 after randomization.

Rate of patients with resolution of hepatitis, defined as hepatitis grade ≤ 1 according to the current National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), at 6 months after randomization.