Study to see how safe is TNG908 at different doses in patients with solid tumors that have a gene called MTAP missing

Prior treatment

• Not have received prior treatment with a PRMT5 inhibitor.

• "_Age: ≥18 years-of-age at the time of signature of the main study ICF _Performance status: a)Patients with solid tumors other than R/R GBM: ECOG performance status score of 0 to 1 b) Patients with R/R GBM: Karnofsky performance status score ≥70 _For solid tumors other than R/R GBM, have confirmed histologic or cytologic diagnosis of a locally advanced, metastatic, and/or unresectable solid tumor or for GBM, have R/R GBM _Prior standard therapy, as available _Documented bi-allelic (homozygous) deletion of MTAP in a tumor detected by a validated NGS test, or absence of MTAP protein in a tumor detected by a validated IHC test. _Adequate organ function/reserve per local labs _Adequate liver function per local labs _Adequate renal function per local labs _Negative serum pregnancy test result at screening _Patient must be able to swallow tablets _Written informed consent must be obtained according to local guidelines"