NEW YORK (AP) — WeightWatchers is shaking up its leadership.

WW International announced Friday that CEO Sima Sistani would leave her role effective immediately. Tara Comonte, a WeightWatchers board member and former Shake Shack executive, was made interim chief executive.

The New York-based weight loss company didn't reveal the reasons behind the abrupt move, but it noted that Comonte would step into the role of CEO at a time when the company is “focused on improving its operational and financial performance.”

WeightWatchers, which was founded more than 60 years ago, has struggled some recently. Its latest earnings reports showed slipping profits and costs racked up from restructuring efforts. Its stock also has plummeted over time. WW shares are down more than 90% over the last year; now trading as a penny stock, they closed at about 83 cents on Friday.

Sistani joined WeightWatchers as CEO more than two years ago. During her tenure, she led the company's recent moves into the prescription drug weight loss business — particularly with the $106 million acquisition of Sequence, now WeightWatchers Clinic, a telehealth service that helps users get prescriptions for drugs like Ozempic, Wegovy and Trulicity.

Prior to joining WeightWatchers, Sistani co-founded Houseparty, a now-discontinued social networking app that offered group video chatting. In addition to serving as CEO of Houseparty, Sistani was previously a senior leader at Epic Games.

Comonte joined WeightWatchers' board back in June 2023. Most recently, she was CEO of fertility company TMRW Life Sciences — and worked as president and CFO of Shake Shack prior to that. Beyond her current position at WeightWatchers, she also serves on the boards of Kindbody and Strava, according to the company.

In a statement, Comonte said she looked forward to working with WeightWatcher leadership “as we advance the company’s strategy to expand access and care during this critical period of our transformation.”

With Sistani stepping down from her position on the board, WeightWatchers said it would reduce the size of its board from nine to eight members.

WeightWatchers previously reduced its board from 10 to nine members earlier this year — after former talk show host Oprah Winfrey stepped down. Winfrey, who had served on WeightWatchers' board since 2015, said in February that she would leave her position and donate all of her interest to the National Museum of African American History and Culture, part of the Smithsonian Institution in Washington.

The move came after Winfrey told People magazine that she was using a weight-loss medication in December 2023. At the time of her departure, the company said that Winfrey aimed to “eliminate any perceived conflict of interest."