Hydroxychloroquine and lopinavir/r arms stopped in the WHO SOLIDARITY study

Simon Collins, HIV i-Base

On 4 July, the WHO announced that two experimental arms of the international SOLIDARITY study – using hydroxychloroquine and lopinavir/r – were now stopped based on results from an interim analysis. [1]

The decision was also based on results from other studies that was presented at the WHO Summit on COVID-19 research and innovation from 1-2 July 2020. This would have included similar results that were recently announced from the UK RECOVERY study.

The press release is not very clear on other aspects of the study and provides no further details of the results, other than that these will be published later. 

As of 1 July 2020, nearly 5500 patients have been recruited in SOLIDARITY from 21 of the 39 countries that have approval to begin recruiting. [2]

The remaining two arms in SOLIDARITY are remdesivir and a dual combination of lopinavir/r plus interferon beta-1a. It is unclear whether lopinavir/r will also be discontinued in this second arm.


It is important that ongoing studies promptly respond to new evidence that becomes available on both the investigational interventions and the management of COVID-19 in general.

These negative results should also prompt closer review of studies where DSMB access to unblinded data is not showing any clear signal of efficacy.


  1. WHO. WHO discontinues hydroxychloroquine and lopinavir/ritonavir treatment arms for COVID-19. (4 July 2020).

This report was first published on 5 July 2020.

Links to other websites are current at date of posting but not maintained.