Cabozantinib is correlated with progression-free survival among patients with metastatic renal cell carcinoma, according to a new study.
The research, presented on Oct. 10 at the annual congress of the European Society for Medical Oncology in Copenhagen, explains the process of inhibiting the actions of MET and AXL in the body, along with the vascular endothelial growth factor receptors, or VEGFR.
The study compares cabozantinib, which Exelixis markets as Cabometyx, to sunitinib, branded as Sutent from Pfizer. While the latter targets the VEGFR, cabozantinib manages to target MET and AXL as well. A total of 157 patients with untreated clear-cell metastatic renal cell carcinoma with poor and intermediate risk were subjected to an A/B test. Some were given 60 mg of cabozantinib every day, and some were given 50 mg of sunitinib every day. The trial was conducted for four weeks on and two weeks off.
The research did not involve patients with higher risks, but principal investigator Dr. Toni Choueiri, director of the Lank Center for Genitourinary Oncology in Boston, believes there was no clinical reason to believe that the trial with cabozantinib treatment would be less efficient for that segment of patients, as well.
The patients treated with cabozantinib experienced a 31 percent decrease in the median rate of progression or death compared to the ones treated with sunitinib. Along with this positive outcome, the response rate was also decidedly increased in the experimental treatment compared to the old one.
"Both MET and AXL seem to be associated with tumor progression but more importantly, animal models showed that the development of resistance to VEGFR inhibitors like sunitinib can be mediated through AXL and MET," said Choueiri.
During the trial, the researchers noticed similar rates of adverse events with the incidence starting from grade 3 - 70.5 percent in the cabozantinib and 72.2 in the sunitinib treatments. The most prevailing adverse reactions to any of the two treatment methods are diarrhea, fatigue, hypertension and palmar-plantar erythrodysesthesia. No less than 16 patients in each test decided to give up the treatments because of the toxicity levels.
The chairman of the renal cancer unit at Institut Gustave-Roussy in France, Dr. Bernard Escudier, explained that sunitinib, the most widely used standard of care for this type of affectation in patients with cancer, has recently failed being effective, which cabozantinib managed to overcome.
Although the study is under no circumstance exhaustive, what remains to be tested is whether the cabozantinib-based treatment should be a first-line treatment.