A real penalty would be releasing GlaxoSmithKline's patents to the public domain, throwing their board members in jail, and excluding the corporation from doing any further business in the USA.
Individual persons have suffered much worse penalties for lesser crimes.
The courts could confiscate GlaxoSmithKline's facilities, fire unethical management and sales staff, and under government contract turn the production facilities over to those employees who actually produce effective medicines
Individual persons competing directly with the big pharmaceutical companies, let's say people who grow marijuana for little old ladies on chemotherapy, are aggressively pursued by the DEA who will confiscate both production facilities and product. But our government leaves these criminal pharmaceutical giants alone, maybe giving them a slight scolding whenever they kill and maim people or engage in unethical and illegal business practices.
A small restaurant caught selling beer to a twenty year old will have it's liquor license revoked, often leading to the demise of the business. The crimes committed by GlaxoSmithKline are worse. But three billion dollars in fines, high priced lobbying, and political campaign contributions has bought this mega-corporation a lot of "protection."