Merck’s New Keytruda Shot Is a Rare Real-Time ‘Product Hop’ (1)

Merck & Co.‘s planned debut this fall of an injectable form of its breakthrough cancer treatment Keytruda will simplify care, expand access, and save more lives, the company says. But by shifting patients to a version protected by newer patents, it will also extend Merck’s control over the world’s best-selling drug.

Merck is performing a sleight-of-hand known as a “product hop” by tweaking how the drug is delivered. The pivot will preserve its exclusivity and could box out lower-cost rivals for Keytruda, which last year made $29.5 billion globally.

“Product hopping is not something companies do without a good ...