Press Release

Modis Therapeutics Announces that MT1621 Receives Breakthrough Therapy Designation from FDA for the Treatment of TK2 Deficiency

Designation Based on Compelling Data from Initial Clinical Studies and High Unmet Need in Thymidine Kinase 2 Deficiency

Oakland, Calif., February 19, 2019 – Modis Therapeutics announced today that the FDA has granted Breakthrough Therapy designation to MT1621, Modis’ investigational treatment for patients with thymidine kinase 2 deficiency (TK2d).

Breakthrough Therapy designation is a process designed to expedite the development and review of drugs that are intended to treat a serious or life-threatening condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s). A drug that receives Breakthrough Therapy designation is eligible for intensive guidance on an efficient drug development program, organizational commitment involving senior managers from the FDA, and all Fast Track designation features, including eligibility for Accelerated Approval and Priority Review, if relevant criteria are met.

Modis’ application was supported by data from initial clinical studies in TK2d patients, some of which was presented by Dr. Michio Hirano at the International World Muscle Society (WMS) Congress in October 2018. MT1621 has also been granted PRIME designation by the EMA and Orphan Drug designation by both the FDA and EMA.

“We are very pleased that – by granting MT1621 Breakthrough Therapy and PRIME designations – now both FDA and EMA have recognized the urgent need in TK2d patients and encouraging preliminary data that Modis and its collaborators have collected,” said Joshua Grass, Chief Executive Officer of Modis Therapeutics. “We are looking forward to coordinating with FDA and EMA on the registration plan for MT1621 for TK2d patients.”

About TK2 Deficiency

Thymidine kinase 2 deficiency (TK2d) is a genetic disorder that results in mitochondrial dysfunction, leading to inadequate energy production in cells. TK2d may present at all ages and causes progressive and severe muscle weakness, respiratory insufficiency, and is often fatal. There are currently no approved therapies for this disease. To learn more, please visit

About MT1621

MT1621 is an investigational deoxynucleoside combination therapy that targets the underlying pathophysiology of TK2 deficiency. Deoxynucleoside combination therapy has been shown to improve cell function and prolong life in preclinical models of TK2d. Data from initial clinical studies suggest that this therapy may meaningfully alter the course of disease in patients with TK2d. Modis is planning to conduct additional clinical studies with the goal of obtaining regulatory approval to make MT1621 available to patients globally.

About Modis Therapeutics

Modis Therapeutics, Inc. is a biopharmaceutical company focused on developing disease-modifying therapies for rare genetic diseases with high unmet medical need. It was formed in 2016 through a collaboration with academic experts in mitochondrial biology. The company's lead program (MT1621) is in clinical development for thymidine kinase 2 deficiency (TK2d), an inherited mitochondrial disease. Modis Therapeutics is headquartered in Oakland, CA, with offices in New York City.  For more information please visit


Aaron Mishel
VP Finance & Administration
Modis Therapeutics, Inc.
(510) 806-8564