London, March 24, 2026, 18:30 GMT
- GSK closed up 2.07% at 1,977 pence in London, while its U.S.-listed shares traded about 1.7% higher in New York. 1
- Japan granted orphan-drug designation to risvutatug rezetecan for small-cell lung cancer on Monday. 2
- Regulatory filings also showed recent share purchases by Chair Jonathan Symonds and director Gavin Screaton, alongside continued buybacks. 3
Shares in GSK closed up 2.07% at 1,977 pence on Tuesday, outpacing the FTSE 100’s 0.72% rise, a day after the British drugmaker said Japan had granted orphan-drug designation to its experimental lung cancer therapy risvutatug rezetecan. 1
The move matters now because investors are looking for proof that GSK can keep its pipeline moving as Chief Executive Luke Miels tries to speed development and add new medicines ahead of looming patent expiries in the group’s HIV business. “We need to accelerate what we have,” Miels said in February, laying out a plan built around faster R&D and bolt-on deals. 4
The Japan designation lands amid a run of recent regulatory wins. The U.S. Food and Drug Administration last week approved Lynavoy for severe itching linked to primary biliary cholangitis, a chronic liver disease, and earlier this month widened the U.S. label for RSV vaccine Arexvy to at-risk adults aged 18 to 49, putting GSK up against Pfizer and Moderna in that age band. 5
In Japan, orphan-drug status is reserved for medicines that address high medical need in diseases affecting fewer than 50,000 patients in the country. GSK said the tag, its sixth global regulatory designation for risvutatug rezetecan, was backed by preliminary data in extensive-stage small-cell lung cancer, or SCLC; the drug is an antibody-drug conjugate, a targeted cancer medicine that links an antibody to a cell-killing payload. 6
The disease is hard to treat and moves fast. GSK said most patients with extensive-stage SCLC relapse after initial therapy and median overall survival under standard care is about eight months; in the same broad setting, Amgen’s Imdelltra already holds full U.S. approval after platinum-based chemotherapy.
Separate filings gave investors another signal. GSK disclosed on Monday that Chair Jonathan Symonds bought 5,000 ordinary shares on March 20 at an average 19.5111 pounds each, while director Gavin Screaton bought 6,335 shares on March 18; the company also said it had repurchased 560,000 shares for treasury under its buyback programme. 3
Even after Tuesday’s bounce, the shares remain 13.37% below their 52-week high of 2,282 pence reached on Feb. 18. GSK’s U.S.-listed shares were up about 1.7% at $52.87 in New York afternoon trade. 1
But orphan designation is not an approval, and it is not revenue. GSK said the Japanese decision rests on early phase I data, while its global phase III study in relapsed extensive-stage SCLC only began in August 2025, leaving a long stretch of clinical and regulatory risk ahead.
There is also little sign that broker caution has vanished. MarketScreener reported on Tuesday that Deutsche Bank analyst Emmanuel Papadakis kept a neutral rating on GSK with a 1,900-pence target, below the London close. 7
