The Food and Drug Administration (FDA) has accepted for review the New Drug Application for Kyzatrex® (testosterone undecanoate; Marius Pharmaceuticals) for the treatment of primary and secondary hypogonadism in adult males. 

Kyzatrex is an investigational, oral testosterone undecanoate softgel that utilizes lymphatic absorption and phytosterols to increase bioavailability and provide a favorable pharmacokinetic profile. 

The NDA is supported by data from the 12-month, multicenter phase 3 ReTUne study ( NCT04467697), which assessed the efficacy and safety of Kyzatrex for primary and secondary hypogonadism in 295 males aged 18 to 65 years with a total testosterone less than or equal to 281ng/dL. Results showed that greater than 96% of patients who completed 90 days of treatment achieved average testosterone levels in the normal range. Hypertension was reported as the most common treatment-emergent adverse event.

A Prescription Drug User Fee Act (PDUFA) target date of October 31, 2021 has been set for the application. If approved, the Company plans to launch Kyzatrex immediately. The FDA has conditionally accepted Kyzatrex as the trade name for this investigational drug.


  1. Marius Pharmaceuticals receives PDUFA date for Kyzatrex® NDA for treatment of hypogonadism. [press release]. Raleigh, NC: Marius Pharmaceuticals; March 11, 2021. 
  2. Marius Pharmaceuticals submits New Drug Application to U.S. FDA for next-generation oral testosterone replacement therapy in male patients with hypogonadism. [press release]. Raleigh, NC: Marius Pharmaceuticals; January 5, 2021.