A Phase IA/IB Trial of Leflunomide in Patients With PTEN-Altered Advanced Solid Malignancies and HER2 Negative Breast Cancer

Inclusion Criteria: * Age ≥ 18 * A) Advanced or metastatic solid tumor with lack of PTEN expression as determined by immunohistochemistry. Lack of PTEN expression is defined as the absence of staining in the tumor (\<5%), with strong positive staining of adjacent normal endometrium or stromal cells, using the monoclonal DAKO antibody 6H2.1.9 OR * B) Advanced or metastatic solid tumor with a deleterious somatic mutation in PTEN as determined by tissue or ctDNA testing in a CLIA laboratory and classified as deleterious in the ClinVar or COSMIC databases OR * C) Advanced or metastatic HER2 negat…