Moderna shares surge more than 70% as its melanoma vaccine trial meets its primary endpoint

Moderna shares jumped more than 70% in premarket trading after the company reported positive interim results from INTerpath-001, a trial of its individualised mRNA cancer therapy in patients with melanoma. Investment bank William Blair upgraded the stock to Outperform from Market Perform on the back of the data.

The trial tested intismeran autogene — an investigational therapy tailored to each patient's own tumour — in combination with Merck's established immunotherapy Keytruda, in patients whose stage IIB-IV melanoma had been completely surgically removed. It met its primary endpoint of recurrence-free survival and a key secondary endpoint on distant metastasis-free survival.

At a glance

• Shares rose more than 70% in premarket trading on the results
• William Blair upgraded Moderna to Outperform from Market Perform
• INTerpath-001 tested intismeran autogene alongside Merck's Keytruda
• Patients had completely resected stage IIB-IV melanoma
• Trial met its primary endpoint of recurrence-free survival and a key secondary endpoint on distant metastasis-free survival

What an individualised cancer vaccine actually is

The therapy is not a vaccine in the everyday sense. Rather than protecting against infection, it is manufactured for one patient: the tumour is sequenced, the mutations that make it distinctive are identified, and an mRNA construct is built to teach that patient's immune system to recognise those specific markers.

Paired with a checkpoint inhibitor such as Keytruda, which releases the brakes on the immune response, the aim is to catch microscopic disease left behind after surgery — the cells that cause a cancer to come back years later.

Why the endpoints matter

Recurrence-free survival is the right primary endpoint for this setting, because these patients have already had their visible disease removed. The question is not whether a tumour shrinks but whether it returns, and that is what the trial reported an improvement in.

The secondary endpoint on distant metastasis-free survival matters just as much clinically. Melanoma that recurs locally is treatable; melanoma that has spread to the lungs, liver or brain is a different disease. Delaying that spread is the outcome oncologists care most about.

The investment case behind the upgrade

William Blair analyst Myles Minter framed the upgrade around diversification, saying Moderna now has a clear line of sight to revenue that does not depend on its Covid business. That has been the central bear argument against the stock since demand for Covid boosters collapsed.

A share price rising 70% on interim data is also a statement about how low expectations had fallen. Moderna spent the post-pandemic years as a case study in a one-product biotech running down its cash pile; the market is now pricing a second act.

The cautions that come with interim data

Interim results are not approval. The trial must mature, the full dataset must be published and scrutinised, and regulators in the US, EU and UK will each form their own view. Analyst commentary suggests the results position Merck and Moderna to file for approval, but filing is not the same as clearance.

There is also a manufacturing question that has no precedent at scale. A therapy built individually for each patient cannot be mass-produced in the ordinary sense, and turnaround time from biopsy to dose becomes a clinical constraint as well as a logistical one.

What happens next

Watch for the full dataset at a major oncology conference, the regulatory filings that follow, and any read-across to the other tumour types in the INTerpath programme. Success in melanoma has historically been the gateway for immunotherapy into lung, kidney and bladder cancer.

For UK patients, any approval would then face the separate question of NHS cost-effectiveness. A bespoke therapy manufactured per person is unlikely to be cheap, and that negotiation tends to take considerably longer than the science.