How Much of a Cancer Drug Is Too Much? Patients, Researchers Challenge FDA-Approved Dosages

Deciding the appropriate dosage for cancer drugs like nivolumab can be a challenging task for patients and doctors alike. For six months in 2022, economist Chuck Manski received monthly infusions of nivolumab to combat advanced melanoma. However, he experienced severe side effects, including thyroid gland damage and severe dryness in his eyes, lips, and mouth.

Despite the FDA recommending a full year of treatment, Manski decided to stop the therapy when he found no signs of cancer improvement and concluded that the intense side effects might have signaled the drug's limit. Similar experiences were reported in Canada, Israel, and Sweden, where doctors were already using lower doses or shorter durations of nivolumab and pembrolizumab (Keytruda), the latter being a similar drug.

In India, oncologists found that as little as one-twelfth of the labeled dosage of nivolumab had a significant impact on several types of cancer. Researchers, doctors, and patients are advocating for more studies to determine the optimal dosage, as taking smaller doses or shorter periods could potentially save billions of dollars and reduce severe side effects.

However, pharmaceutical companies often resist reducing the recommended dosages due to the direct impact on their profits. For instance, Merck's pembrolizumab generated nearly $32 billion in sales last year, accounting for about half of the company's drug revenue. Despite the potential benefits of lower dosages, drugmakers argue that the prescribed doses have been established through extensive testing, and any changes could compromise the drug's effectiveness.