Following Failed COVID-19 Treatment, NRx Prioritizes Bipolar Depression Candidate, NRX-101
Pennsylvania-based NRx Pharmaceuticals has refocused its priorities around its psychiatry franchise and lead asset, NRX-101, a treatment for severe bipolar depression with acute suicidal ideation and behavior (ASIB).
This shift in focus, announced in its quarterly financial report, follows the failure of its trial assessing Zyesami (aviptadil) for the treatment of COVID-19 patients. Monday morning, the company said during the second quarter, it reactivated the development of NRX-101 and intends to initiate a Phase IIb/III study for ASIB by the end of this year or early 2023.
The U.S. Food and Drug Administration awarded NRX-101 Breakthrough Therapy designation and a special protocol agreement for this indication, according to Stephen Willard, NRx Chief Executive Officer, who assumed the leadership role last month. He takes over from Robert Besthof, head of operations and chief commercial officer, who served as interim CEO following Jonathan Javitt's decision to step down from that role and shift into the position of chief scientific officer earlier this year.
While the company awaits the beginning of the ASIB study, NRx has already initiated a Phase II trial of NRX-101 in patients with bipolar depression and sub-acute suicidal ideation & behavior (SSIB). Willard said the purpose of the study is to expand the potential indication for NRX-101, as SSIB contains a significantly larger patient population than ASIB. A readout of this study is expected by the end of 2022 or in early 2023.
"It is estimated that 50% of individuals with bipolar disorder attempt suicide over their lifetime. We believe NRX-101 is a potentially life-saving medicine that could change the treatment paradigm for individuals with bipolar depression that are also experiencing suicidality," Willard said during a call with investors.
The development of NRX-101 had been placed on the backburner during the COVID-19 pandemic due to the difficulty of enrolling patients. Instead, the company focused on developing Zyesami as a potential therapeutic for patients infected with the SARS-CoV-2 virus.
In the early days of research, Zyesami had seen real-world use through the federal Right to Try programs. Company data showed that 17 of 19 COVID-19 patients treated with the medication under the Right to Try program recovered from their illness. However, in May, a clinical study of Zyesami in COVID-19 managed by the National Institutes of Health was halted for futility.
This morning, Willard said the company is awaiting the data from the NIH study so it can conduct its independent review. Once that is completed, NRx will determine future development plans for the drug.
With the development of Zyesami halted, for now, NRX-101 has become the primary focus of NRx and has become the basis for its psychiatric franchise. Willard said the experimental drug, a fixed-dose combination product of D-cycloserine and lurasidone, has enormous application for depression patients, particularly those who have suicidal tendencies. There are multiple drugs on the market for bipolar depression patients but many of them contain warnings for increased risks of suicide.
"To our knowledge, NRX-101 is the only oral antidepressant in the bipolar segment that targets patients with active suicidality," Willard said.
Beyond bipolar depression, other forms of depression include risks of suicidality, including among the nine million U.S. patients with post-traumatic stress disorder. Of those millions, a significant number of patients are at risk of suicide, and the company believes that NRX-101 will be an effective treatment for them.
In the company's previously conducted Phase II STABIL-B trial, NRX-101 demonstrated a significant reduction in both depression and suicidality compared to standard therapy in acutely suicidal patients who were first stabilized with ketamine.
"Unlike ketamine, the components in NRX-101 have not shown the potential for addiction and are not neurotoxic," Willard added. "It achieves the same effect but has the advantage of not being addictive. We believe we are in a unique position to deliver a highly differentiated product to help patients."