Background and AimThis study aimed to investigate whether telephone follow-up by clinical pharmacists for unresectable hepatocellular carcinoma (HCC) patients treated with lenvatinib (LEN) contributes to improved adherence and treatment duration for LEN. MethodsThis retrospective study enrolled 132 patients with HCC who were treated with LEN. The patients were classified into non-telephone follow-up (n = 32) or telephone follow-up groups (n = 100) [the latter group was further classified into family-pharmacist (FP) telephone follow-up (n = 18), or hospital family-pharmacist (HFP) telephone follow-up (n = 82) groups]. ResultsThe progression-free survival (PFS) in the telephone follow-up group was significantly higher than that in the non-telephone follow-up group (PFS 6.1 months vs 3.7 months, P = 0.001, respectively). Although treatment duration was significantly longer in the telephone follow-up group than in the non-telephone follow-up group [median treatment duration: 10.4 months vs 4.1 months, P = 0.001, respectively.], no significant differences were noted between the HFP telephone follow-up group and FP telephone follow-up groups (10.3 months vs 13.3 months, P = 0.543). Self-interruption and adverse-event discontinuation in the HFP-telephone follow-up group were significantly lower than those in the FP-telephone and non-telephone groups (0% vs 11.1% vs 18.8%; P < 0.001, 25.6% vs 33.3% vs 53.1%; P = 0.022, respectively). ConclusionsTelephone follow-up contributes to prolonged treatment duration for LEN in patients with HCC treated. Moreover, telephone follow-up with an HFP may further improve treatment adherence.