The world’s biggest pharmaceutical companies, looking to sell a new type of cancer drug that could transform treatment, are grappling with an unusual challenge: finding patients.
The new medicines aim to shrink tumors by targeting a rare genetic anomaly — appearing in 1,500 to 5,000 patients’ tumors in the U.S. annually — that can spur cancer’s growth. Bayer AG is out in front with a drug that could go on sale by the end of the year. Roche Holding AG is pursuing the same target.
Neither potential treatment can turn into a commercial success unless doctors and insurers embrace expensive new tests. Roche on Tuesday agreed to spend $2.4 billion to gain control of a company that makes such products. To identify just one potential candidate, doctors will need to peer into the DNA of as many as 100 patients at a cost of thousands of dollars a person.
“The question of access is really a question of whether a doctor will decide to do the test,” said Fabrice André, a professor in the department of medical oncology at Institut Gustave Roussy near Paris. “What is going to be the uptake of doctors to prescribe a test that detects 1...