A change to intellectual property laws could also fix the problem. The government could allow others to sell the drug but give a percentage of their revenue to the rights holder.

But capital is also political power. The capitalists interact with the system that structures their markets, their property rights, their contract law, their regulations, their hierarchies etc. The system itself is a strange loop which ultimately leads to contradictions. A capitalist acting in their rational self interest modifies the system in order to improve it for their own ends. This inevitably means deviations from the neoclassical ideal.

If there's one useful idea from the marxists, it's that the dominant modes of economic activity of the day determine the structures of our institutions, not the other way around. It may not be completely true, but the way capital dominates all other forms of power in the world is fundamentally troublesome. Capitalism eats itself, and every crisis requires a lot of bloodshed and suffering from the unpropertied in order to keep the system going forward.

People and other animals follow incentives.