The ADIUVO study is a prospective, randomized, open-label, controlled, international, phase III trial for patients with ACC after radical resection.
In a parallel group design, patients will be randomized 1:1 to receive adjuvant therapy with mitotane or observational follow-up only. The overall study duration is 4 years from initial recruitment. Key inclusion criteria are: histologically confirmed diagnosis of ACC according to Weiss system; patient age ≥18 years; low/intermediate risk of recurrence defined as ENS@T stage I-III ACC, no evidence of microscopically residual disease and Ki-67 (MIB1) labeling index ≤ 10%. Key exclusion criteria are: history of prior malignancy; previous or current treatment with mitotane or other antineoplastic drugs; time between primary surgery and randomization >3 months, and repeated surgery for ACC recurrence. In the treatment arm, mitotane will be administered orally and adjusted according to target plasma levels (> 14 μg/l) and tolerability. Mitotane will be administered until ACC recurrence, intolerable toxicity, and consent withdrawal or until a treatment period of 2 years has been reached.
In the control arm, patients will receive no adjuvant treatment but will be monitored closely for recurrence with the same procedures as for treated patients.