Shares in Moderna have nearly tripled after the vaccine maker reported successful trial results for an experimental skin cancer therapy jointly developed with Merck. The therapy, a custom‑made mRNA vaccine for each patient, targets melanoma by attacking the patient’s specific tumour.

The company hailed the results as an important milestone toward vaccinating patients with the disease and is hoping to extend the technology to treat different types and stages of cancer.

The trial’s success boosted Moderna’s share price by 177%, adding $44bn to its market capitalisation and taking it to $69.6bn. With the surge, the company became the second‑best performer in the S&P 500 index so far in 2026, trailing only memory group Sandisk.

Analysts at TD Cowen called it a "landmark moment" and expect regulatory approval next year, quickly followed by patient sales, though uncertainties remain.