LONDON, March 18: Four men, seriously ill after taking part in a clinical drug trial in Britain, have regained consciousness and spoken to their families, doctors said on Saturday.

Of the six men who took part in testing a drug designed to treat chronic inflammatory conditions and leukaemia, two have been taken off organ support after responding to treatment.

Medical staff said two other men were receiving less organ support as their condition improves, but that the condition of the two remaining drug test volunteers remains critical.

“In response to the treatment they have had, two patients have improved sufficiently to stop receiving organ support. They do still need high dependency care and remain under the supervision of the critical care team,” the statement from Northwick Park Hospital in north London said.

“Two of the other men remain in a serious condition but are gradually receiving less organ support.”

All six men continue to be given anti-inflammatory drugs to treat their conditions. They suffered multiple organ failure within hours of testing a new antibody therapy known as TGN 1412.

Relatives and friends of the two men most badly affected have said the volunteers’ features became severely swollen.

Doctors have said the six men could make a full recovery.

The trial was being run by US drug research company Parexel International Corp. on behalf of German pharmaceutical company TeGenero AG.—Reuters