Cabozantinib has shown antitumor activity in patients with advanced bone cancer including Ewing sarcoma and osteosarcoma. This could mean a possibly new therapeutic option for patients with bone cancer. The findings were reported in The Lancet Oncology on Monday.
Though Ewing sarcoma and osteosarcoma are rarer forms of cancer, the average overall survival after diagnosis is just 12 months. This means after a diagnosis with this type of bone cancer, on average a person is more likely to be dead within a year.
The study was funded by Institut Bergonié, French National Cancer Institute, and Association pour la Recherche sur le Cancer. The study’s objective was to examine the effects and efficacy of cabozantinib in patients with advanced bone cancer.
Efficacy in pharmaceutical terms is the capacity of the drug to produce a sufficient therapeutic effect in patients in clinical settings. It can also refer to the maximum response achievable from a drug in research settings.
The participants included patients with advanced Ewing sarcoma and osteosarcoma recruited from 10 centres of French Sarcoma Group. All the participants included had to fulfil the criteria of being 12 years and older, having a documented disease progression, and an Eastern Cooperative Oncology Group performance status of 0–1. No patients were excluded based on number of previous treatments.
This multi-center, single-arm, two-stage, phase 2 trial had 90 patients (45 of each cancer type). The study showed that the cabozantinib was indeed effective in producing a favorable result in patients with bone cancer. However, of all the patients, 68 percent showed at least one adverse effect. An adverse effect is just an undesired harmful side effect of the drug. These side effects include diarrhea, low calcium, increased liver enzymes, mouth sores, weight loss, nausea, fatigue, oral pain, low platelets and high blood pressure. No deaths were reported from drug related toxic effect.
These results are in line with the previous studies published on the subject. Previously, it has been seen that Cabozantinib helps inhibit the bone cancer growth by directly affecting tumor cells and modifications in the bone microenvironment. Cabozantinib is an oral receptor tyrosine kinase inhibitor and works as a blocker in MET signaling pathways. Currently, cabozantinib is approved for use in metastatic medullary thyroid cancer (MTC), advanced renal cell carcinoma, and hepatocellular cancer (HCC).
Ewing sarcoma, named after Dr. James Ewing, was first described in 1921. Ewing tumors are most common among white people. Most of these sarcomas develop in bones but can also develop in tissues and organs. The most common sites for this cancer are pelvis, chest wall and long bones of arms and legs. Osteosarcoma, on the other hand, is the most common primary bone cancer and is more often diagnosed in men than women. These tumors also develop in legs, arms and pelvis.
American Cancer Society estimates that 3,600 new cases of bone and joints cancer will be diagnosed this year with estimated deaths of 1,720 people. In adults, nearly 8 percent of bone cancers are Ewing tumors and 28 percent of bone cancers are osteosarcomas. Both cancers occur more frequently in children and teens as compared to adults.