Lawyers for four of six men who almost died after medical trials went wrong have criticised the US research company for awarding its boss £920,000.
The trials took place in laboratories at Northwick Park
Gene Matthews said the cash and share bonus package awarded to Parexel chief executive Josef von Rickenbach had "incensed and outraged" his clients.
Reports suggest the men risk developing cancer and auto-immune diseases after having reactions to the drug TGN1412.
Mr Matthews said: "The timing of this really couldn't have been worse."
According to accounts released by Parexel, Mr von Rickenbach - who founded the clinical research organisation and is also its chairman - got a cash bonus of $286,157 and share options worth $1,469,490 this year.
This makes a total of around $1.76m dollars (£920,000). His basic salary was $465,750, which means his overall package was $2,221,397 (£1.16 million).
The six previously healthy men volunteered to test the medication, designed to treat rheumatoid arthritis, leukaemia and multiple sclerosis.
But shortly after they were injected with it their heads and bodies rapidly swelled up. One had all his toes and parts of his fingers amputated.
The trials were carried out at Parexel's laboratory at Northwick Park Hospital in north-west London in March on behalf of TeGenero, a German pharmaceutical company.
Mr Matthews said his clients were "bitterly disappointed" at the payment made to Mr von Rickenbach.
He said: "This payout comes at a time that's very close to what happened to these men, in the same year.
"They haven't received any compensation apart from the £10,000 payment for immediate medical expenses.
"They are struggling with their finances and their health and that's made even more difficult when executives are getting bonuses of that size.
"It's very much insensitive."
Mr Matthews said the group were still considering taking legal action against Parexel.
"We are hoping to avoid going to court, but the longer time goes on without a solution being reached then the more that becomes an option."
Along with Mr Matthews, the group of men are represented by Martyn Day, who said the payout was an "insult".
He said: "It is astonishing that they are prepared to pay the chief executive this sort of money, at a time when they are refusing to sit round the table with the guys who have been injured."
The men have only received £10,000 each so far as "interim payments" from the insurance company for TeGenero.
A report by the Medicines and Healthcare products Regulatory Agency, the Government's drug watchdog, said Parexel had failed to follow several procedures.
A spokeswoman for Parexel said it did not wish to comment.