• Pfizer's CEO signed on to an open letter calling for the reversal of a federal judge's decision to suspend the Food and Drug Administration's approval of the abortion pill mifepristone.
• Albert Bourla was among the more than 200 pharmaceutical company executives who signed the letter after U.S. Judge Matthew Kacsmaryk's controversial ruling Friday. 
• The executives expressed support for the FDA's authority to regulate drugs and said Kacsmaryk's decision "ignores decades of scientific evidence and legal precedent."

Pfizer's CEO signed on to an open letter calling for the reversal of a federal judge's decision to suspend the Food and Drug Administration's approval of the abortion pill mifepristone.

Albert Bourla was among the more than 200 pharmaceutical company executives who signed the letter after U.S. Judge Matthew Kacsmaryk's controversial ruling Friday.

"We call for the reversal of this decision to disregard science, and the appropriate restitution of the mandate for the safety and efficacy of medicines for all with the FDA, the agency entrusted to do so in the first place," the letter said.

The executives said Kacsmaryk's decision "ignores decades of scientific evidence and legal precedent." They also raised concerns that the ruling will "set a precedent" for diminishing the FDA's authority over drug approvals, which would create uncertainty for the entire industry. 

"If courts can overturn drug approvals without regard for science or evidence, or for the complexity required to fully vet the safety and efficacy of new drugs, any medicine is at risk for the same outcome as mifepristone," the executives wrote in the letter. 

They added that regulatory uncertainty will likely reduce incentives for investing in new drugs, which would endanger the "innovation that characterizes our industry." 

Pfizer is one of the first major pharmaceutical companies to publicly react to the ruling. Among the other executives who signed the letter are Biogen President Alisha Alaimo and Cristal Downing, Merck's chief communications and public affairs officer.

The letter included a link to a Google form for other executives and employees to add their names.

Moderna, Eli Lilly and Johnson & Johnson did not immediately respond to requests for comment regarding the letter.

On Monday, the primary lobbying arm of the pharmaceutical industry, PhRMA, issued a separate statement saying Kacsmaryk's ruling undermines the regulatory process.

"The FDA is the gold standard for determining whether a medicine is safe and effective for people to use," said Priscilla VanderVeer, PhRMA's vice president of public affairs. "While PhRMA and our members are not a party to this litigation, our focus is on ensuring a policy environment that supports the agency's ability to regulate and provides access to FDA-approved medicines."

Kacsmaryk sided with an anti-abortion group, arguing the FDA rushed its approval process and violated federal standards. He suggested the agency ignored mifepristone's serious safety risks due to "political pressure."

"The Court does not second-guess FDA's decision-making lightly," Kacsmaryk wrote in his decision. "But here, FDA acquiesced on its legitimate safety concerns — in violation of its statutory duty — based on plainly unsound reasoning and studies that did not support its conclusions."

In the open letter, executives acknowledged that the FDA's drug development and approval process is not perfect. But they defended the agency's longstanding determination that mifepristone is a safe and effective method to terminate an early pregnancy.

The abortion pill "has been proven by decades of data to be safer than Tylenol, nearly all antibiotics and insulin," the executives wrote in the letter.

The FDA declined to comment on the letter, directing CNBC to the agency's statement on Saturday.

"[Mifepristone's] approval was based on the best available science and done in accordance with the laws that govern our work," that statement said.

The FDA approved mifepristone in 2000. Medication abortion has become the most accessible and preferred method for terminating a pregnancy in the U.S. since then, accounting for more than half of all abortions nationwide.

Mifepristone will be available in the short term, because Kacsmaryk delayed his order for a week to give the Biden administration time to appeal.

Kacsmaryk's decision conflicts with a ruling by a federal judge in Washington state. Less than an hour after the Texas ruling, the Washington state judge issued a preliminary injunction that could protect access to mifepristone in the 17 states and Washington, D.C., that brought a lawsuit arguing that too many regulations exist on the drug.

The dueling orders by two federal judges create a complicated legal standoff that could potentially escalate to the Supreme Court.

— CNBC's Meg Tirrell and Spencer Kimball contributed to this report.