Because patents are filed before the start of clinical trials, rather than when a drug actually hits the market, drugs that require long clinical trials effectively receive shorter patent terms. This reduces incentives to develop drugs that require long clinical trials, including many preventive medicines.
A simple way to correct this is for the Food and Drug Administration to guarantee a minimum baseline of 12 years of market exclusivity for branded drugs. Importantly, this would not change or lengthen protection for drugs that would be developed anyway; most already receive 12 to 16 years of market protection, and the United States already provides this for particular categories, such as biologic drugs. For drugs with short periods of market exclusivity, this policy could make the difference between the drug being developed or not.
Here is the full Op-Ed, likely correct throughout.