Azithromycin Plus Hydroxychloroquine for COVID-19 Infection

This is a randomized, double-blinded, Phase 3, multi-center trial of the clinical and microbiologic response of patients with a respiratory tract infection (RTI) due to coronavirus treated with a combination of azithromycin and hydroxychloroquine. Approximately 200 patients with symptoms of an RTI who test positive for SARS-CoV-2 by polymerase chain reaction (PCR) will receive a combination of azithromycin 500 mg and hydroxychloroquine 600 mg or matching placebos for six consecutive days. There will be two treatment regimens into which patients are randomized so that all patients will receive some active therapy.

As of March 22, 2020, a total of 311,988 people worldwide have been diagnosed with a respiratory infection caused by SARS-CoV-2 of whom 13,407 have died. In the United States 26,747 patients have tested positive of whom 340 have died. There is at present no established therapy for this infection. After the SARS epidemic in 2002, investigations identified chloroquine as a possible inhibitor of replication of this coronavirus. When the SARS-CoV-2 epidemic started in December of 2019, clinicians began to use chloroquine in an attempt to control the infection in newly diagnosed patients. Investigators from China reported chloroquine phosphate has apparent efficacy in treatment of pneumonia due to SARS-CoV-2. Following this report, investigators in France initiated an open label study of hydroxychloroquine, with the addition of azithromycin, in a small number of subjects with SARS-CoV-2 infection. Relative to no treatment the investigators identified a significant reduction in viral isolation by PCR in the nasal swabs of treated patients, with an additional effect seen when patients were also given azithromycin. Azithromycin, like chloroquine, is a weak base that concentrates in endosomes and lysosomes and raises the pH in those vesicles. It is possible that azithromycin and chloroquine's effect on endosomal processing reduces the inflammatory response by affecting TLR4 signaling through the endosomes.