A new report by nonprofit group Initiative for Medicines, Access & Knowledge (I-MAK) exposes the prime offenders of the U.S. patent system, the pharma giants who are taking advantage of its loopholes to amass huge profits.

The report mentions one such example where Pfizer hindered the growth of Lyrica by stationing 68 patents in its way. Also, to dismiss encroaching counterfeit drugs, it dished out a patented, durable combination and attracted patients to it, mounting its price by 163%.

 “Pfizer’s patenting strategy with Lyrica illustrates how drugmakers game the patent system in order to extend the patent-protected lifespan of their key products and garner billions more in revenue beyond the twenty year period,” says the report.

As the report remarks, Pfizer is just one among the pharma companies exploiting patent laws to multiply sales. A number of drugmakers have practiced evergreening, a process involving excessive patenting, to prevent generics or biosimilars from coming onto the market in near future, simultaneously rising prices without the dread of low-priced contenders, the report comments.

Based on the 2017 sales, the report listed the 12 highest selling drugs and computed the numbers of patents filed and granted; their rise in prices in the last six years.

It named AbbVie, Roche and Pfizer as the most infamous offenders who used “aggressive and exploitative patenting strategies” to expand their domination and execute noteworthy price hike.

 “Contrary to what the law intends, drugmakers have transformed the patent system into a defensive business strategy to avoid competition and earn outsized profits,” said Tahir Amin, co-founder and co-executive director at I-MAK, in a statement .