ETCTN A Phase II Basket Trial of Glutaminase Inhibitor (BeGIN) CB-839 HCl in Patients with NF1 Aberrations, NF1 Mutant Malignant Peripheral Nerve Sheath Tumors (MPNST), KEAP1/NRF2 and LKB1 Aberrant Tumors Adult CIRB - Early Phase Emphasis Active Available to Open