The EU's medicines regulator said Thursday it has started a review of US drug maker Eli Lilly's mix of two synthetic antibodies to treat high-risk Covid-19 patients. The company says trials have shown that bamlanivimab and etesemivab reduce hospitalisations and deaths in coronavirus patients. The European Medicines Agency (EMA) said it had started a "rolling review" of the two antibodies used in combination, and of bamlanivimab used alone. The start of the rolling review is a precursor to accelerated authorisation for use within the 27-nation European Union. "The decision to start the rolling review is based on preliminary results from two studies," the Amsterdam-based regulator said. The EMA has started evaluating the first batch of data, which come from animal studies, it said. Bamlanivimab and etesemivab are monoclonal antibodies, which are lab-made versions of the body's natural infection-fighting defences. Giving people ready-made antibodies can help those who are at high risk of severe disease because of weak immunity or underlying conditions. Many scientists have welcomed their Covid fighting potential, and both Lilly and biotech firm Regeneron have received emergency use authorisations in the United States for their treatments. But their uptake has been limited by factors including a lack of patient interest, and not enough staffing and places inside hospitals to administer them. The two antibodies have been designed to attach to the spike protein of the coronavirus at two different sites, stopping it from entering the body's cells, the EMA said. Eli Lilly said on Wednesday that the combination of bamlanivimab and etesemivab reduced hospitalisations and deaths in high-risk patients recently diagnosed with Covid-19 by 87 percent in trials. The new results added to previous data reported by the company in January which used different dosing levels for the two antibodies and also showed a drastic risk reduction. jhe/dk/spm