Study of Immunomodulation Using Naltrexone and Ketamine for COVID-19

There is an urgent need to develop new treatments for Novel Coronavirus-19 (COVID-19) infection using easily available and affordable medications. We need to develop a treatment protocol which prevents progression of the disease and a treatment protocol to rescue those with advanced disease. In addition to anti-viral therapeutics currently under investigation in other trials, the addition of immunomodulators to the treatment regimen appears have to potential to act as agents which can reduce the pathogenicity of this disease by reducing the dysregulation of autoimmunity which is destructive of normal tissue and when unchecked rapidly leads to mortality.

COVID-19 infection has three stages and 80% of infected people stay in stage 1 or stage 2A (viral response and early pulmonary effects), however 20% of patients progress to stage 2B (late pulmonary effects), and of those about 20% progress to stage 3 (hyper-inflammation). An ideal treatment for COVID-19 would have a two-pronged strategy: a treatment that would slow or interrupt the progression of the disease from mild/moderate (stage 1-2A) to severe (stage 2B-3), and a treatment to rescue patients who have become severe. Promising data using tocilizumab, an monoclonal antibody targeting the cytokine Interleukin-6 (IL-6), suggests that interrupting IL-6 is one of the potential pathways to accomplish this.

Low-dose naltrexone has been used off-label for treatment of pain and inflammation in multiple sclerosis, Crohn's disease, fibromyalgia and other pain conditions. Lower than standard doses of naltrexone inhibit cellular proliferation of T- and B- cells and block Toll-like receptor 4 (TLR4), providing pain relief and anti-inflammatory benefit. Naltrexone at doses below the normal therapeutic dose appears to reduce production of multiple cytokines including IL-6 in a steady pace and is available as an oral preparation. As such it is ideal to use to attempt to modify progression to stage 2B as it can easily be given to both hospitalized patients and patients in the community.

Ketamine at low doses, below the normal anesthetic dose, appears to rapidly reduce the production of pro-inflammatory cytokines, especially IL-6 and tumor necrosis factor alpha (TNFα), for hours after an event which would induce the inflammatory response. This drug is given intravenously (IV), either by drip or push, and is easily given in a hospital environment. This could not easily be used in the community but could act as a rescue drug with lower cost and easier availability than tocilizumab, a monoclonal antibody targeting IL-6. Ketamine has been extensively studied in a variety of settings and indications with a well-established side-effect and dosing profile. Ketamine is generally well tolerated and remains inexpensive and widely available on the U.S. market and available for immediate use.

The trial will measure the ability of low dose naltrexone to reduce the progression of participants with COVID-19. In this study, naltrexone or placebo will be given to participants in early stages of COVID-19 infection in a randomized, double blinded manner, whereas the use of ketamine will be unblinded and given as a rescue agent should a participant progress. Additionally, should a participant be ineligible for the randomized portion of the study due to already being in a more advanced stage of the disease, they will be given the opportunity to enter the trial to receive ketamine without being randomized to naltrexone vs placebo.