Brussels says it has secured enough of COVID-19 drug remdesivir to treat 30,000 people with the disease.
The drug, manufactured by US pharmaceutical company Gilead, is to be made available from early August to the EU's 27 member states and the UK.
Remdesivir is one of just two drugs proven to treat COVID-19.
The announcement comes four weeks after the US revealed that it had bought more than 500,000 treatment courses — nearly the world's entire supply of the anti-viral drug — through to the end of September.
Remdesivir — now known as Veklury — became the first drug to be authorised by the European Medicines Agency (EMA) to treat patients suffering from the novel coronavirus earlier this month. It was also approved by the US and Japan.
"In recent weeks, the Commission has been working tirelessly with Gilead to reach an agreement to ensure that stocks of the first treatment authorised against COVID-19 are delivered to the EU," Stella Kyriakides, the Commissioner for Health and Food Safety, said in a statement.
The €63 million contract was signed on Tuesday, Kyriakides also said, adding that "yesterday's agreement is another important step forward in our fight to overcome the disease".
The approximately 30,000 treatment courses will be distributed over the next few months "based on an allocation key", the statement continued.
This allocation key will be based on the number of cases and hospital admissions reported in the previous 14 days.
"The Commission is now preparing a joint procurement for further supplies of the medicine, expected to cover additional needs and supplies as from October onwards," it went on.
Remdesivir has been found to reduce recovery time for hospitalised COVID-19 patients — those with the most severe infections — from 15 to 11 days. The effect was not observed in patients with mild and moderate disease.
According to the US Department of Health and Human Services (HHS), a treatment course with remdesivir requires an average of 6.25 vials of the drug and costs approximately $3,200 (€2,850).
The other drug to have been found to have an effect on COVID-19 patients is dexamethasone, a low-cost, widely-available steroid. Authorised for use in the UK, it reduces the number of deaths in the most severely-impacted patients by up to a third, according to British researchers.
The EMA launched its review of the British study into dexamethasone earlier this week.
Europe is the world's second hardest-hit region after the Americas, according to data from the World Health Organisation (WHO), with more than 210,800 fatalities and 3.2 million infections recorded since the beginning of the outbreak.