Multiple Doses and Regimens of Cabozantinib in Subjects With Grade IV Astrocytic Tumors in First or Second Relapse

The goal of this clinical trial is to learn if the drug cabozantinib works for people with astrocytic tumors. It also was designed to learn about the safety of cabozantinib. The main questions are: 1. Does cabozantinib work and how well do patients tolerate the drug for over 12 weeks. 2. Was the drug safe and how well could patients tolerate treatment for the entire treatment period. Participants were assigned to one of the four treatment groups: Arm 1. Take cabozantinib at a dose of 25 mg once every day (po QD) continuously until progression. Arm 2. Take cabozantinib at a dose of 75 mg once every day continuously until progression. Arm 3. Take cabozantinib at a dose of 125 mg once every day for 2 weeks, followed by 50 mg every day (po QD) for the remainder of the treatment period; Arm 4. Take cabozantinib at a dose of 125 mg once every day for 2 weeks, followed by 1 week off. For the remainder of the treatment period, patients received cabozantinib at a dose of 125 mg once every day for three weeks followed by one week of rest.