You apparently use the word trial differently than it is used in pharma. Pfizer had one large trial that involved many sites. Three of those sites run by Venta

You apparently use the word trial differently than it is used in pharma. Pfizer had one large trial that involved many sites. Three of those sites run by Ventavia had problems. That's why the headline says “in trial”. But even if you didn't know that it is explained in BMJ article “... Ventavia had enrolled more than 1000 participants at three sites. The full trial (registered under NCT04368728) enrolled around 44 000 participants across 153 sites that included numerous commercial companies and academic centres.”