She cited an analysis from Private Equity Stakeholder Project showing that 83.4% of the deal financing would come from debt and that many companies Sycamore has acquired, including the Belk department store chain and the Nine West shoe store chain, have gone bankrupt and closed many or all of their stores.

Walgreens has already announced plans to close about 1,200 of its 8,500 U.S. drugstores.

Related: Walgreens to close 1,200 drugstores, in 'turnaround' after $3B loss

"If the Walgreens-Sycamore deal generates even more store closures, that could leave even more Walgreens customers in 'pharmacy deserts,'" Warren wrote in her letter to Kaluzny. "Far too often, private equity buyouts ruin already-struggling companies and produce devastating consequences for workers and communities."

Warren asked Kaluzny about Sycamore's plans for firing Walgreens employees; closing more Walgreens stores; having Walgreens stores sell their property to investors and lease it back; and possibly eliminating the Village Medical, Summit Health or CityMD brands.

She also asked about a Private Equity Stakeholder Project assertion that the proposed 83.4% debt level for the Sycamore-Walgreens deal would be about twice the average debt level for private-equity-backed acquisitions announced in 2024.

"Do you believe this debt level will hinder the company's ability to make the investments needed to restore profitability?" Warren asked.

Representatives from Sycamore were not immediately available to comment.

In the past, Blackmore Partners and other private equity firms have said that turning around struggling companies often involves measures such as cutting costs by reducing staff and focusing on core strengths.