GSK received FDA approval for Jideytro (zidesamtinib), marking early payback on its $10.6 billion acquisition of Nuvalent completed last week. The approval covers adults with locally advanced or metastatic non-small cell lung cancer (NSCLC) driven by ROS1 alterations who previously received a ROS1 kinase inhibitor. The regulator cleared the therapy ahead of a Sept. 18 decision deadline, supported by breakthrough therapy and orphan drug designations that can accelerate review timelines. GSK said Jideytro is a next-generation ROS1-selective option intended to broaden coverage and address resistance mutations, including potential benefit for brain metastases. The accelerated nod underscores how large oncology acquisitions are increasingly timed around regulatory catalysts that can affect near-term revenue contribution and investor sentiment. With ROS1-positive NSCLC estimated at roughly 2% of NSCLC cases, the approval also tests commercial assumptions for new entrants in a space where competing ROS1 inhibitors have struggled to drive category scale.