Gileidomide is an antiretroviral drug.

Its main drug, the Sovaldi, has become the blockbuster drug of its time, but its makers are already paying a price.

Gileadex, the UK-based maker of Sovaldi and a major US-based competitor, reported a third-quarter loss of $4.2bn, or 2.3%.

The company has not released a full statement since it filed the financials.

Analysts were sceptical about the results. 

Gilead’s annual profit fell to $1.9bn from $2.6bn a year ago, due to the drug’s steep price increases.

“Gileadexes main product has been priced up in the past few years to a large extent due to increased costs,” said Peter Gannon, chief executive of medical consulting firm McKinsey & Smith.

“The key drivers are an increase in the cost of development, the need to continue to invest in R&H and to continue building a pipeline of R&amps products.”

Gileady shares are down more than 9% in after-hours trading, but the stock is expected to rise in coming days.

Giliad said the results were “very good”, but declined to comment on the share price, saying the company had a range of plans for the financial year.

“We believe that we are well positioned to deliver an operating profit for the current financial year and the year to come,” it said in a statement. 

It said it would use the funds to focus on R≈H, a “strategic” investment strategy, which involves research, manufacturing and sales.

Giles investment in R &amp ;H includes R&am, its drug development arm, which is also based in Britain.

Gilderoy’s drug, Rituximab, also has a clinical trial that has been given approval.

GILDEROY shares fell 1.3% in afternoon trading to $2,818.99. 

The drugmaker also reported a fourth-quarter profit of $2m.

“This was due to lower costs, higher production volumes and the launch of a new product line,” it added.

“Our outlook for the remainder of the year remains positive, as we continue to focus our investments on R ≈h and R&Am and expect further growth in our growth plans over the next year.” 

Gilderoys share price has dropped from $7,500 last year to $4,814.99 this year.