Farmas USA

Regeneron Antibody Cocktail Lowers Virus in Covid-19 Patients

• As hypothesized, patients in the study consisted of two different populations: those who had already mounted an effective immune response, and those whose immune response was not yet adequate. These populations could be identified serologically by the presence (seropositive) or absence (seronegative) of SARS-CoV-2 antibodies, and/or by high viral loads at baseline.
• Serological status highly correlated with baseline viral load (p<0.0001). Seropositive patients had much lower levels of virus at baseline, and rapidly achieved viral loads approaching lowest levels quantifiable (LLQ), even without treatment. In contrast, seronegative patients had substantially higher viral levels at baseline, and cleared virus more slowly in the absence of treatment.
• Serological status at baseline also predicted how rapidly patients had alleviation of their COVID-19 clinical symptoms. In the untreated (placebo) patients, seropositive patients had a median time to alleviation of symptoms of 7 days, compared to seronegative patients who had a median time to alleviation of symptoms of 13 days.
• REGN-COV2 rapidly reduced viral load through Day 7 in seronegative patients (key virologic endpoint). The mean time-weighted-average change from baseline nasopharyngeal (NP) viral load through Day 7 in the seronegative group was a 0.60 log10 copies/mL greater reduction (p=0.03) in patients treated with high dose, and a 0.51 log10 copies/mL greater reduction (p=0.06) in patients treated with low dose, compared to placebo. In the overall population, there was a 0.51 log10 copies/mL greater reduction (p=0.0049) in patients treated with high dose, and a 0.23 log10 copies/mL greater reduction (p= 0.20) in patients treated with low dose, compared to placebo.
• Patients with increasingly higher baseline viral levels had correspondingly greater reductions in viral load at Day 7 with REGN-COV2 treatment. The mean log10 copies/mL reduction in viral load compared to placebo were as follows:
  -  Viral load higher than 105 copies/mL: high dose (-0.93); low dose (-0.86) (p=0.03 for both); approximately 50-60% reduction compared to placebo
  -  Viral load higher than 106 copies/mL: high dose (-1.55); low dose (-1.65) (p<0.002 for both); approximately 95% reduction compared to placebo
  -  Viral load higher than 107 copies/mL: high dose (-1.79); low dose (-2.00) (p<0.0015 for both); approximately 99% reduction compared to placebo
• Patients who were seronegative and/or had higher baseline viral levels also had greater benefits in terms of symptom alleviation. Among seronegative patients, median time to symptom alleviation (defined as symptoms becoming mild or absent) was 13 days in placebo, 8 days in high dose (p=0.22), and 6 days in low dose (p=0.09). Patients with increasing viral loads at baseline had correspondingly increasing benefit in time to symptom alleviation.
• There were a small number of medically-attended visits given that most non-hospitalized patients recover well at home. Patients in the seronegative group were at higher risk of medically-attended visits: 10 of the 12 medically-attended visits (defined as hospitalizations, or emergency room, urgent care or telemedicine visits for COVID-19) occurred in patients who were seronegative at baseline. In the seronegative group, 15.2% of placebo-treated patients, 7.7% of patients treated with high dose and 4.9% of patients treated with low dose required additional medical visits.
• Both doses were well-tolerated. Infusion reactions were seen in 4 patients (2 on placebo and 2 on REGN-COV2). Serious adverse events occurred in 2 placebo patients, 1 low dose patient and no high dose patients. There were no deaths in the trial.