“This is highly significant, especially at such a high-profile academic center,” Dr. Gellad said in an email. “Leadership matters, and the institution has decided that their leaders should not also be concurrently leading for-profit health companies.”

When doctors enter into financial relationships with companies, the concern is that these ties can shape the way studies are designed and medications are prescribed to patients, potentially allowing bias to influence medical practice. A 2014 study in JAMA found that about 40 percent of the largest publicly traded drug companies had a leader of an academic medical center on their boards.

Ms. Berns said the Memorial Sloan Kettering board’s policy decision was intended to emphasize the hospital’s focus on education, research and treatment of patients. Dr. Nadeem R. Abu-Rustum, who is president of Memorial Sloan Kettering’s medical staff, said the policy changes were “well-received” by employees.

Memorial Sloan Kettering has been shaken by the unfolding series of conflicts of interest since September, when The Times and ProPublica reported that its chief medical officer, Dr. José Baselga, had failed to disclose millions of dollars in payments from drug and health care companies in dozens of articles in medical journals.

Dr. Baselga resigned days later, and he also stepped down from the boards of the drugmaker Bristol-Myers Squibb and Varian Medical Systems, a radiation equipment manufacturer. Earlier this month, AstraZeneca announced that it had hired Dr. Baselga to run its new oncology unit.

Additional reports detailed how other top officials had cultivated lucrative relationships with for-profit companies, including an artificial intelligence start-up, Paige.AI, that was founded by a member of Memorial Sloan Kettering’s executive board, the chair of the pathology department and the head of a research lab. The hospital struck an exclusive deal with the company to license images of 25 million patient tissue slides that had been collected over decades.

Another article detailed how a hospital vice president was given a stake of nearly $1.4 million in a newly public company as compensation for representing Memorial Sloan Kettering on its board.