Revolution Medicines shares surged again early Friday after reports that Merck is in talks to acquire the cancer-drug biotech for up to $32 billion. Earlier in the week, shares jumped nearly 29% to a record high on a Wall Street Journal report that AbbVie had shown takeover interest, a claim the pharma giant later denied. Trading volume more than doubled compared with its 30-day average as investors weighed the potential for a landmark deal in the targeted oncology space.

The U.S. Food and Drug Administration has granted Breakthrough Therapy Designation to zoldonrasib, Revolution Medicines’ RAS(ON) G12D-selective inhibitor, for adult patients with KRAS G12D-mutated locally advanced or metastatic non-small cell lung cancer previously treated with anti-PD-1/PD-L1 therapy and platinum-based chemotherapy. This marks the first designation for an investigational agent specifically targeting the KRAS G12D mutation and the third RAS(ON) inhibitor from the company—following daraxonrasib and elironrasib—to earn this status. The decision is based on Phase 1 RMC-9805-001 monotherapy data demonstrating encouraging antitumor activity and an acceptable safety profile in patients with advanced KRAS G12D solid tumors.

In after-hours trading on Wednesday, Revolution Medicines shares fell by 11.5% following AbbVie’s confirmation to Reuters that it was not engaged in acquisition discussions. The decline erased much of the earlier rally driven by takeover rumors, underscoring the sensitivity of investor sentiment to deal speculation. Despite the pullback, trading remains elevated as market participants reassess the company’s standalone value and the strategic importance of its pipeline in RAS-addicted cancers.