Exelixis's cabozantinib has demonstrated positive effects in treating hepatocellular carcinoma (HCC) cohort patients during the ongoing Phase 2 randomized discontinuation trial (RDT).
Cabozantinib, which is a potent, dual inhibitor of MET and VEGFR2, provides coordinated inhibition of metastasis and angiogenesis to destroy tumor cells while blocking their escape pathways.
The study, which involved 41 patients, showed tumor regression in 78% of patients, including those with or without prior sorafenib therapy, and 68% disease control rate (PR and SD) at week 12.
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 confirmed partial response (cPR) in two patients and stable disease (SD) in 32 patients.
The study also showed a >50% reduction in the tumor marker alpha-fetoprotein (AFP) serum level in ten (38%) of 26 patients with AFP levels of = 20 ng/mL at baseline and at least one post baseline measurement.
The study also reported a median progression-free survival (PFS) of 4.2 months, which was similar for sorafenib-pretreated and sorafenib-naïve patients.
Exelixis president and CEO Michael M. Morrissey said they are very encouraged by the disease control rates observed in this population of patients with hepatocellular carcinoma.
"Importantly, the similar PFS data in patients with and without prior sorafenib therapy is noteworthy, given the widespread use of this treatment as first-line therapy for HCC," Morrissey added.
"These data warrant further study and we hope to investigate cabozantinib further in HCC as part of our recently announced cooperative research and development agreement (CRADA) with the National Cancer Institute's Cancer Therapy and Evaluation Program."
The Rocky Mountain Cancer Center Medical Director of Research Allan Lee Cohn said the compelling results highlight cabozantinib's potential clinical utility in HCC.
"In particular, the anti-tumor activity in patients with and without prior sorafenib therapy suggests we may see additional benefit for pretreated and treatment-naïve patients through simultaneous inhibition of MET and VEGF signaling, rather than VEGF alone," Cohn added.