The confusing state of affairs about the patentability of life sciences inventions arguably traces its roots to a seminal 2010 decision that will be part of retiring Supreme Court Justice Anthony Kennedy’s legacy.

Bilski v. Kappos, authored by Kennedy, marked the first time in decades the Supreme Court tinkered with the statute that sets out what can be patented, 35 U.S.C. § 101. With the dam broken, other members of the court authored three more decisions in rapid...