CAMBRIDGE, Mass.—Epizmyme, Inc., a clinical stage biopharmaceutical company creating novel epigenetic therapeutics for cancer patients, has announced that the United States Food and Drug Administration (FDA) has granted Orphan Drug status to the company's first-in-class EZH2 inhibitor, tazemetostat, for the treatment of malignant rhabdoid tumors (MRTs). In December 2015, the company initiated a Phase 2 study in adults and a Phase 1 study in children with genetically defined tumors, including MRTs. Tazemetostat is also being investigated in an ongoing five-arm Phase 2 study in patients with non-Hodgkin lymphoma.
"Malignant rhabdoid tumors are rare and aggressive cancers with poor outcomes. There have not yet been any targeted drugs developed specifically to treat these patients," said Peter Ho, M.D., Ph.D., chief medical officer, Epizyme. "In an ongoing Phase 1 study, tazemetostat has demonstrated encouraging clinical activity and an acceptable safety profile in patients with these severe types of cancer. We believe tazemetostat has the potential to become an important targeted therapy for patients with MRT and we are working aggressively to execute our clinical development program."
Orphan drug designation provides the sponsor of the drug with eligibility for various development incentives, including tax credits for qualified clinical testing and marketing exclusivity for a period of seven years. Therapies with orphan drug status are also not subject to a prescription drug user fee for the orphan indication.
Currently, treatment of MRT consists of surgery, chemotherapy and radiation therapy, which are associated with limited efficacy and significant treatment-related morbidity. MRT is a tumor defined by loss of INI1 protein as measured by immunohistochemistry. Other rhabdoid tumors, such as MRT of ovary, are characterized by loss of the protein SMARCA4 and have shown sensitivity to tazemetostat in preclinical models and in a Phase 1 study. The orphan drug designation applies to both INI1-negative MRT as well as SMARCA4-negative MRT of ovary.
The ongoing Phase 2 adult and Phase 1 pediatric studies in patients with genetically defined solid tumors include patients with rhabdoid tumors, other INI1-negative tumors, and synovial sarcoma. Interim data from Epizyme's registration-supporting phase 2 clinical study of tazemetostat in adult patients with genetically defined solid tumors, including MRT, other INI1-negative tumors and synovial sarcoma, are anticipated to be presented at a medical conference in late 2016.
EZH2 is a histone methyltransferase (HMT) that is increasingly understood to play a potentially oncogenic role in a number of cancers. These include non-Hodgkin lymphoma, INI1-negative cancers such as malignant rhabdoid tumors and epithelioid sarcomas, certain SMARCA4-negative solid tumors, synovial sarcoma, and a range of other solid tumors.
Epizyme is developing tazemetostat for the treatment of patients with non-Hodgkin lymphoma and for patients with INI1-negative solid tumors, certain SMARCA4-negative solid tumors and synovial sarcoma. Tazemetostat is a first-in-class small molecule inhibitor of EZH2 created by Epizyme using its proprietary product platform. In some human cancers, aberrant EZH2 enzyme activity results in dysregulation of genes that control cell proliferation resulting in the rapid and unconstrained growth of tumor cells. Tazemetostat is the WHO International Non-Proprietary Name (INN) for compound EPZ-6438.
Epizyme, Inc. is a clinical-stage biopharmaceutical company creating novel epigenetic therapeutics for cancer patients. Epizyme has built a proprietary product platform that the company uses to create small molecule inhibitors of chromatin modifying proteins (CMPs), such as histone methyltransferases or HMTs. CMPs are part of the system of gene regulation, referred to as epigenetics, that controls gene expression. Genetic alterations can result in changes to the activity of CMPs, making them oncogenic. By focusing on the genetic drivers of cancers, Epizyme's targeted science seeks to match the right medicines with the right patients.