A California class-action lawsuit has accused pharmaceutical giant Gilead Sciences of intentionally inflating prices for its life-saving HIV drugs. The lawsuit alleges that the "long-running scheme" involved the firm blocking generic competition, allowing it to keep prices for its own products at an inflated level.

According to the suit filed on Monday, the company's actions have caused the prices of its products to incrementally rise over the past few years. Gilead is also accused of violating the country's antitrust laws as it maintained its monopoly over the HIV drug market.

Gilead currently sells a combination of drugs, often used as a cocktail, to treat HIV. The combination antiretroviral therapy, as it is called, is one of the more popular options for HIV positive consumers in the United States to treat their condition.

Apart from Gilead, the lawsuit also names a number of drug manufacturers that are allegedly part of the scheme. This includes pharmaceutical giants such as Johnson & Johnson subsidiary Janssen Pharmaceuticals and Bristol-Myers Squibb.

The plaintiffs alleged that these companies took part in a scheme to extend patent protection for their products, which in turn resulted in "exorbitant" prices.

The suit further alleges that the company's monopoly has caused innovation stagnation in the development of better treatments. The plaintiffs claim that this has caused tens of thousands of people to needlessly suffer from side effects from inferior products.

The accused companies also apparently entered into "collusive agreements" that basically prevented them from competing with each other's products.

The companies also allegedly prevented third-party players from competing against Gilead's HIV treatment. All of the companies have yet to release statements in response to the allegations, with the exception of Bristol-Myers. The firm mentioned that it had already received the complaint, but is still in the process of reviewing it.

Gilead's HIV drug combination has been proven to be effective in reducing the levels of the virus in the bloodstream. The drug cocktail also helps in reducing the effects of the virus, including reducing the damage to an infected person's immune system and the risk of acquiring AIDS-related diseases.

According to the suit, more than 80 percent of all HIV patients in the United States use Gilead's product every day. The cocktail of drugs reportedly generated more than $11 billion in revenue for Gilead each year. Following the news of the class action lawsuit, Gilead stock prices remained unchanged.