Testing LOXO-101 as Potentially Targeted Treatment in Cancers With NTRK Genetic Changes (MATCH - Subprotocol Z1E)

This phase II MATCH treatment trial tests how well larotrectinib (LOXO-101) works in treating patients with cancer that has certain genetic changes. Larotrectinib (LOXO-101) is used in patients whose cancer has a mutated (changed) form of a gene called NTRK. It is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.

Inclusion Criteria: * Patients must have met applicable eligibility criteria in the Master MATCH Protocol EAY131/ NCI-2015-00054 prior to registration to treatment subprotocol * Patients must fulfill all eligibility criteria of MATCH Master Protocol at the time of registration to treatment step (Step 1, 3, 5, 7) * Patients must have a malignancy harboring an NTRK1, NTRK2 or NTRK3 gene fusion, as determined by the MATCH screening assessment * Patients must have an electrocardiogram (ECG) within 8 weeks prior to treatment assignment and must have no clinically important abnormalities in rhythm, conduction or morphology of resting ECG (e.g. complete left bundle branch block, third degree heart block) * Patients must not have known hypersensitivity to larotrectinib (LOXO-101) or compounds of similar chemical or biologic composition * Patients with inability to discontinue treatment with a strong CYP3A4 inhibitor or inducer prior to start of treatment are excluded * Patients who have previously received treatment with a TRKA, TRKB, or TRKC inhibitor are excluded. Such inhibitors include larotrectinib (LOXO-101), entrectinib (RXDX-101), TSR-011, DS6051, altiratinib (DCC-2701), MGCD516, dovitinib (TKI258, CHIR528), AZD7451, PLX7486, and BIBF1120