Epizyme announced that the FDA has accepted for filing the company’s New Drug Application (NDA) for accelerated approval of tazemetostat for the treatment of patients with metastatic or locally advanced epithelioid sarcoma not eligible for curative surgery. The FDA granted Priority Review for the NDA and has set a Prescription Drug User Fee Act (PDUFA) target action date of January 23, 2020. Priority Review is granted to investigational therapies that, if approved, may offer significant improvements in the treatment, prevention or diagnosis of a serious condition.
Epizyme’s NDA submission is based primarily on data from the 62 patient epithelioid sarcoma cohort of its ongoing Phase 2 study of tazemetostat. This data was reported at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting by Silvia Stacchiotti, M.D., Fondazione IRCCS Istituto Nazionale Tumori, Milan. The data is from a cohort that includes 24 treatment-naive patients and 38 relapsed and/or refractory patients for a total of 62 adult and pediatric epithelioid sarcoma patients (at least 16 years of age). Patients enrolled were administered 800 mg of tazemetostat orally twice daily. The primary endpoint of the study is objective response rate (ORR), comprised of complete and partial responses as measured by RECIST 1.1. As of the September 17, 2018 cutoff date, treatment with tazemetostat resulted in a 15% ORR and a 26% disease control rate (DCR). The median duration of response (DOR) has not yet been reached. Tazemetostat was generally well-tolerated with favorable safety.
To support full approval of tazemetostat for epithelioid sarcoma, Epizyme is planning a global confirmatory trial. The randomized, controlled clinical trial in the front-line treatment setting will compare tazemetostat in combination with doxorubicin versus placebo plus doxorubicin in approximately 150 patients. The primary efficacy endpoint will be progression-free survival, and secondary efficacy endpoints will include overall survival, disease control rate, overall response rate and duration of response. The confirmatory study is expected to begin in the second half of 2019.
About Epithelioid Sarcoma
Epithelioid Sarcoma is rare cancer that most often occurs in the soft tissue of the fingers, hands, and forearms of young adults. It may also be found in the legs, trunk, head or neck regions. It is rare in young children and adults, and it occurs more frequently in men. Epithelioid sarcoma begins as a painless, firm growth or bumps that may be accompanied by an open wound (ulceration) in the skin covering the growth. It is considered aggressive cancer because it has a high chance of regrowth after treatment, or spreading to surrounding tissues or more distant parts of the body (a metastasis).
Tazemetostat is an orally administered, first-in-class small molecule EZH2 inhibitor. EZH2, which belongs to the class of histone methyltransferases, is overexpressed or mutated in a variety of cancer cells and plays a key role in tumor cell proliferation.