GSK’s First Lung Cancer Drug Wins FDA Approval: Jideytro Enters Later-Line ROS1-Targeted Treatment Market

Lung cancer targeted therapy has gained another later-line drug designed to address resistance. The U.S. Food and Drug Administration (FDA) approved GSK’s Jideytro (zidesamtinib) for adults with locally advanced or metastatic ROS1-positive non-small cell lung cancer who have previously received at least one ROS1 tyrosine kinase inhibitor. It is also GSK’s first approved lung cancer drug.

The approval was based primarily on data from 117 patients in ARROS-1, a single-arm, multicohort trial. The confirmed objective response rate was 44%, meaning that tumors shrank by a predefined amount in about four in ten patients. Among responders, 82% maintained their response for at least 6 months and 69% for at least 12 months. These results indicate that the drug may continue to control tumors after existing ROS1-targeted treatment has failed, but the trial had no randomized control group, making it impossible to directly determine how much it extends survival compared with other later-line strategies.

Jideytro is taken orally once daily at a recommended dose of 100 milligrams. The drug was designed to address certain ROS1 resistance alterations and cross the blood-brain barrier; the latter is particularly important in lung cancer, which is prone to brain metastases. However, the core data supporting the current approval still concern overall tumor response. The relative benefits for patients with different resistance mutations or brain metastases must still be defined through more comprehensive subgroup analyses.

The safety assessment pooled 446 patients who received the drug. Common adverse reactions included edema, peripheral neuropathy, constipation, fatigue, and shortness of breath. The drug label also warns of risks including central nervous system reactions, QTc interval prolongation, interstitial lung disease or pneumonitis, fractures, and pancreatic toxicity. For patients who need ongoing treatment, these warnings mean that treatment cannot be assessed solely by whether tumors shrink; symptoms, electrocardiograms, and relevant organ function must also be monitored.

### Background

ROS1 fusion-driven non-small cell lung cancer can be inhibited by targeted drugs, but tumors may develop resistance after treatment or progress again because of central nervous system lesions. Jideytro is not aimed at the first-line treatment market, but at patients who need a new option after receiving at least one ROS1 inhibitor. Its clinical position will therefore depend on prior treatment, resistance mechanisms, brain lesions, and individual safety risks.

The FDA completed its assessment through the Real-Time Oncology Review pilot program, approving the drug about two months ahead of the original September 18, 2026 target date. Jideytro originated from GSK’s recently completed acquisition of Nuvalent. This approval not only formally brings GSK into the lung cancer drug market, but also rapidly transforms a research and development asset centered on resistance and brain penetration into a commercial product.

However, completing the review early does not mean that all clinical questions have been answered. Existing evidence supports Jideytro’s durable tumor-shrinking activity, but is not yet sufficient to rank it directly against other ROS1 inhibitors. More mature data on duration of response, progression-free survival, and overall survival, as well as results in populations with different prior treatments and brain metastases, are still needed to establish its true place in the treatment pathway.