Investors sue to block private equity firms’ $18B acquisition of Hologic

Investors have filed a class action lawsuit to block two private equity firms’ plans to acquire breast imaging vendor Hologic for $18.3 billion. 

The Marlborough, Massachusetts-based mammography systems manufacturer revealed details about the litigation in a filing with the U.S. Securities and Exchange Commission on Monday. Plaintiffs charge that Hologic has omitted key information from public disclosures about the deal, violating New York laws, with attorneys hoping to stop the deal’s progress until more information is revealed. 

“Although the outcome … cannot be predicted, the company believes that the allegations contained in these matters are without merit,” Hologic said in its Jan. 26 SEC filing. 

Hologic did not immediately respond to a Radiology Business request for comment on the lawsuit Monday. 

The company on Monday attempted to satisfy some of investors’ concerns about the merger deal and alleged incomplete disclosures related to it. In the SEC filing, Hologic said it expects to generate approximately $1.703 billion in unlevered free cash flow between 2026 and 2035, based on forecasts calculated by Goldman Sachs. Further, Hologic held approximately $300 million in net debt as of September and expects to log earnings per share of roughly $4.81, $5.25 and $5.85 in 2027, 2028 and 2029, respectively.

The breast imaging vendor first announced the blockbuster deal in October, with Blackstone and TPG offering to pay approximately $79 per share to take Hologic private. Leaders originally said the transaction is expected to be finalized in the first half of 2026, subject to approval by Hologic's own stockholders, regulators, and other customary closing conditions. Its board already has granted unanimous approval of the merger agreement, recommending that shareholders do the same. 

In Monday’s filing, Hologic also disclosed additional details about issues with two of its products. Following a stop-ship order initiated in November and a subsequent voluntary recall of its Brevera 9 Gauge Needles, sales are expected to be adversely impacted for an extended period. The biopsy devices accounted for about 5% of Hologic’s breast health revenue in fiscal 2025. Meanwhile, another class-action lawsuit related to its BioZorb implantable breast device has reached a settlement and is expected to be resolved soon, with insurance covering the damages.