[DigitalToday reporter Jinju Hong] Moderna's shares surged about 177 percent in a single day after the company posted positive results from the first phase 3 clinical trial of a personalised mRNA-based cancer treatment. Moderna, which has focused on finding new growth drivers since its COVID-19 vaccine, delivered a major clinical milestone in cancer treatment, sharply lifting market expectations.

On Aug. 19, local time, blockchain media outlet Decrypt reported that Moderna said the phase 3 INTerpath-001 trial met its main endpoints for a combination of its personalised neoantigen therapy intismeran autogene and Merck's immunotherapy Keytruda.

The trial involved patients with stage 2B to 4 melanoma who had tumours removed through surgery. The company explained that the combination met targets on two main measures: recurrence-free survival and distant metastasis-free survival.

The results are seen as the first case in which a personalised neoantigen therapy has shown positive results in phase 3, and the first time an mRNA-based cancer treatment has demonstrated efficacy in a phase 3 trial.

The combination produced better results on the two main measures than Keytruda alone, which is used as a standard treatment. It was also the first time that a personalised neoantigen therapy, as adjuvant therapy to prevent cancer recurrence after surgery, showed a clinically meaningful improvement over an existing blockbuster immunotherapy.

The biggest feature of intismeran autogene is that the treatment is designed differently for each patient. Instead of administering the same mass-produced drug, it analyses mutations found in a patient's tumour and designs personalised mRNA based on that analysis.

The mRNA induces the patient's body to produce specific protein fragments that the immune system can recognise. The approach is designed to prompt the immune system to find and attack cancer cells carrying the protein. Keytruda is added to increase the treatment effect. Keytruda is a PD-1-blocking immunotherapy that lifts the so-called 'immune brake' that works as cancer cells evade immune attack. Using the two treatments together is intended to help the immune system find and eliminate cancer cells that may remain after surgery.

Market reaction was immediate. Moderna shares closed at $174.38, up 177 percent from the previous day, and shares of Merck, which sells Keytruda, also rose.

Moderna's high short interest is also cited as a factor that amplified the stock's jump. As concerns continued over performance and growth prospects after its COVID-19 vaccine, Moderna has been classified as one of the large-cap stocks with high short interest. At the time, short interest amounted to 13.5 percent of the free float.

As the stock surged, mark-to-market losses for short sellers expanded to about $4.8 billion. If short sellers buy back borrowed shares to reduce losses, a short squeeze can occur as rising prices spur further buying. ORTEX co-founder Peter Hillerberg (피터 힐러버그) said losses per shorted share had grown to nearly $100, and mentioned the possibility that such pressure could trigger a short squeeze.

The trial results do not immediately mean the treatment will be commercialised. Moderna and Merck plan to continue tracking overall survival and other secondary endpoints that have not yet been disclosed.

A key question going forward is whether the results could change the standard of care for adjuvant therapy in melanoma after surgery. It is also important whether personalised mRNA technology can show efficacy in other cancer types beyond melanoma.

Moderna, which demonstrated the potential of mRNA technology with its COVID-19 vaccine, is drawing attention over whether it can open a new market with a personalised treatment that targets the characteristics of each patient's cancer. If the first phase 3 success is reproduced in follow-up trials and expanded indications, the scope of mRNA technology could broaden in earnest from infectious disease vaccines to cancer treatment.