At the same time, on behalf of themselves and their investors, Mr. Bass and Mr. Spangenberg are short-sellers of shares in companies whose patents they consider vulnerable. They also buy stock in companies whose patents, they believe, reflect true innovation.

Drug companies have cried foul, criticizing the coalition for trying to profit from successful challenges that may pressure a company’s revenue and shares. When drugs come off patent and can be sold by generic drug makers, their prices plummet.

Big pharmaceutical companies moaning about others profiteering at their expense? That’s rich.

The patent appeal board hasn’t given the complaints much credence. In a case brought by Celgene requesting sanctions against the coalition and its review requests, the board ruled against Celgene. It noted in its ruling that “profit is at the heart of nearly every patent” and nearly every patent review.

Mr. Bass and Mr. Spangenberg say the coalition’s aim is to bring down drug prices that are kept artificially high by dubious patents. And on Wednesday, they filed two new patent challenges that they’re pursuing on a pro bono basis. To help draw attention to their campaign, the coalition will pay all the costs of the two reviews and will have no financial interest in either outcome.

“Some patents and extensions to patents represent an unreasonable use of government regulation to enshrine monopoly power to the detriment of the public at large,” Mr. Bass said. “This system must be fixed or we will continue to pay more and more for the same old drugs we’ve been buying for decades.”