Study of How Safe and Effective Tarlatamab is in Brain Cancers

This study is testing a drug called tarlatamab in people with certain types of brain tumors — specifically IDH-mutant gliomas (a type of slow-growing brain cancer with a specific genetic mutation). Tarlatamab is an immunotherapy drug that targets cancer cells. The study includes people who may or may not be candidates for further surgery. **You may be eligible if...** - You are 18 years or older and weigh more than 40 kg - You have an IDH-mutant diffuse astrocytic or oligodendroglial brain tumor (confirmed by biopsy using WHO 2016 classification) - You have had up to 2 previous rounds of treatment after your tumor came back - Your organs and blood counts are functioning well - You are in good general health (ECOG performance status assessed by your doctor) **You may NOT be eligible if...** - Your tumor does not have the IDH mutation - You have had more than 2 lines of treatment after relapse - Your organ function does not meet the required levels Talk to your doctor to see if this trial is right for you.