GSK Tender Offer for RAPT Therapeutics Clears HSR, Faces Shareholder Lawsuits
RAPT has more than doubled off its 52-week low of $5.665.
Summary
GSK's tender offer for RAPT Therapeutics has cleared a major regulatory hurdle with the expiration of the HSR Act waiting period, but the acquisition now faces two shareholder lawsuits and multiple demand letters alleging disclosure deficiencies.
Key Events · M&A and Partnerships · RAPT
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HSR Act Waiting Period Expired
The waiting period under the HSR Act expired on February 23, 2026, at 11:59 p.m. Eastern Time, satisfying a key regulatory condition for the tender offer.
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Shareholder Lawsuits Filed
Two complaints were filed in New York state court on February 3 and February 5, 2026, by purported stockholders, alleging negligent misrepresentation and concealment based on statements in the Schedule 14D-9.
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Demand Letters Received
The company also received twelve demand letters from purported stockholders regarding alleged disclosure deficiencies in the Schedule 14D-9.
Analysis · RAPT · Life Sciences
This amendment provides a critical update on the ongoing acquisition of RAPT Therapeutics by GSK. The expiration of the HSR Act waiting period satisfies a key regulatory condition, moving the tender offer closer to completion. However, the disclosure of two new shareholder lawsuits and twelve demand letters introduces new legal risks and potential delays to the transaction. While such lawsuits are common in M&A deals, they can lead to additional costs or minor adjustments to disclosures, though they rarely derail a deal entirely, especially one trading at the offer price.
How filings like this one have moved
In the 30 days to Oct 5, 2026, 36.9% of the 964 measured filings Wiseek scored 8 moved their stock by 5% or more by the next session's close. The median move was -0.65%. These are measured outcomes after filings of this importance, not a forecast for this one.
Measured one observation per ticker per day, after exclusions. Current figures: Filing Impact Tracker · open dataset
At the time of this filing, RAPT was trading at $57.98 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $1.6B. The 52-week trading range was $5.67 to $57.98. This filing was assessed with neutral market sentiment and an importance score of 8 out of 10.