Exelixis, Inc.'s Cabozantinib Demonstrates Evidence of Anti-Tumor Effects in Heavily Pretreated Patients with Hepatocellular Carcinoma

Exelixis, Inc. reported positive updated interim data from the cohort of hepatocellular carcinoma (HCC) patients participating in the ongoing phase 2 randomized discontinuation trial (RDT) of cabozantinib. The results comprise data from 41 patients with advanced hepatocellular carcinoma with measurable disease at baseline and documented progressive disease per RECIST criteria. Patients in the open label 12-week Lead-In Stage of the trial received a daily dose of 100 mg cabozantinib. Eligible patients had Child-Pugh Score A. 8% had received 1-2 prior lines of systemic therapy: 56% had prior tyrosine kinase inhibitor (TKI) therapy, including 51% previously treated with sorafenib. At baseline, extrahepatic spread of disease (which is associated with a poorer prognosis) was present in 73% of subjects, 39% had hemoglobin (Hb) < 11 g/dL, 34% had thrombocytopenia, and median alpha-fetoprotein (AFP) level was 368 ng/ml. Tumor assessments per original RECIST 1.0 were conducted using conventional CT/MRI at baseline and every 6 weeks thereafter. The week 12 disease control rate (partial response [PR] and stable disease [SD] at week 12) was 66%. Evidence of objective tumor regression was observed in 78% of patients, including those with or without prior sorafenib therapy. The best radiologic response per RECIST in the Lead-In stage of the study for 36 patients with at least one post-baseline measurement was PR in 2 patients (5%) and SD in 32 patients (78%).