CML is generally well treated with kinase inhibitors and, as far as I know, there are no planned trials for menin inhibitors. Menin inhibitors work for NPM1 and MLL rearrangement leukemias because they both drive the cancer by overexpression of pro-growth/survival genes, such as HOX family genes. Both mutations work by epigenetically deregulating the regions around these genes, such as the HOXA locus. The inhibition of menin, a protein cofactor needed for this epigenetic deregulatory process, counteracts the abnormal expression of these genes by preventing the epigenetic changes from occurring. While there is some evidence (I found with a brief search) that HOX genes are aberrantly expressed in CML, it doesn't appear to be crucial for the leukemia to survive. So it is unlikely that a menin inhibitor would be effective, but without preclinical testing, we don't know that for sure.