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HCQ study #52 of 231
6/5 Late treatment study
RECOVERY Collaborative Group, NEJM, doi:10.1056/NEJMoa2022926 (press release 6/5) (Preprint)
Effect of Hydroxychloroquine in Hospitalized Patients with COVID-19: Preliminary results from a multi-centre, randomized, controlled trial
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RECOVERY trial finds no significant benefit for very late stage very sick patients. Results may be due to the unusually high dosage used (9.2g total over 10 days) [1, 2].
The overall dosage used is only 23% less than the high dosage that Borba et al. show greatly increases risk (OR 2.8) [3].
Authors do not report results based on weight, BMI, or related conditions such as diabetes, which may provide additional evidence of toxic dosages. Authors do not adjust dosage based on patient weight, so toxicity may be higher in patients of lower weight.
KM curves show a spike in HCQ mortality days 5-8, corresponding to ~85% of the total excess seen at day 28 (a similar spike is seen in the SOLIDARITY trial).
Authors will not release the data until Jan 8, 2021.
Authors note: "we did not observe excess mortality in the first 2 days of treatment ... when early effects of dose-dependent toxicity might be expected", but they are ignoring the very long half-life of HCQ and the dosing regimen - much higher levels of HCQ will be reached later. Increased mortality in Borba et al. occurred after 2 days.
Patients were extremely sick (median 9 days post symptoms, 60% requiring oxygen and an additional 17% requiring ventilation/ECMO), and an unusually high death rate was seen in both arms. 1,561 HCQ patients, 3,155 SOC.
A secondary analysis has found several inconsistencies in the data: [4]. Hypoxia may inhibit HCQ entering cells [5], making it less effective for late stage use.

RECOVERY et al., 6/5/2020, Randomized Controlled Trial, United Kingdom, Europe, preprint, 29 authors.
risk of death, 9.0% higher, RR 1.09, p = 0.15, treatment 421 of 1561 (27.0%), control 790 of 3155 (25.0%).
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