In this research study, the investigators are trying to determine whether lorlatinib is effective in controlling the growth of cancer cells after they have spread to the CNS. Another purpose of this study is to determine why the cancer cells that have spread to the participant CNS have continued to grow despite treatment with other drugs. For this reason, blood samples will be collected as part of this study to assess the DNA released by the participants cancer cells into their blood when the cells travel to other sites in their body.