Moderna Dips in After-Hours Trading After Cancer Vaccine Surges 177%; Merck, Pfizer, BioNTech and Other mRNA Concept Stocks Active

Wednesday evening, multiple healthcare stocks became market focus due to sharp intraday gains.

mRNA Concept Stocks Pull Back After Explosive Trading

Moderna Inc. fell 4.65% to $166.26 in after-hours trading. The biotech stock had surged as much as 176.97% to $174.38 during the session before retreating.

Merck & Co. Inc. also declined 0.46% to $151.50 after hours, following a sharp intraday gain of 12.60% to $152.20.

Merck, Moderna Report Landmark Phase 3 Cancer Therapy Trial Results

These stock moves stem from positive Phase 3 results from the INTerpath-001 trial announced by Merck and Moderna before Wednesday's market open. The two companies have jointly developed intismeran autogene, a personalized mRNA-based cancer therapy, since 2016. The therapy is customized using patients' own tumor samples to generate a targeted immune response.

The trial evaluated intismeran in combination with Merck's anti-PD-1 immunotherapy KEYTRUDA, which is already approved as an adjuvant treatment for resected stage IIB, IIC, or III melanoma.

The combination therapy significantly improved recurrence-free survival and distant metastasis-free survival compared to KEYTRUDA alone. This marks the first positive Phase 3 results reported for a personalized neoantigen therapy and an mRNA-based cancer therapy.

The trial enrolled 1,137 patients with completely resected stage IIB-IV melanoma. The study will continue to evaluate other endpoints, including overall survival.

Related Concept Stocks Also Fluctuate in After-Hours Trading

BioNTech SE fell 0.55% to $112.50 after hours, following an intraday gain of 21.96%. BioNTech is also developing mRNA-based personalized cancer therapies, falling into the same treatment category as Merck and Moderna's intismeran autogene.

Tempus AI Inc. declined 0.41% to $61.00 after hours, pulling back from an intraday gain of 24.09%. Tempus AI provides genomic sequencing and precision oncology data to match cancer patients with targeted therapies, a category that includes personalized neoantigen therapies like intismeran.

Crispr Therapeutics AG fell 0.15% to $59.72 after hours, following an intraday gain of 12.91%. Crispr Therapeutics develops gene-editing therapies, including cancer treatments, and like Moderna, operates within the broader biotech and cell/gene therapy space.

Pfizer Inc. also edged down 0.50% to $28.10 after hours. Pfizer's relatively modest gain reflects its indirect exposure to Wednesday's news. The company co-developed the Comirnaty mRNA COVID-19 vaccine with BioNTech and continues to collaborate on updated formulations, but unlike Moderna and BioNTech, Pfizer does not have its own late-stage mRNA-based cancer vaccine program.

Stock Performance

Stock Market Cap 52-Week Range YTD Gain

Moderna $69.62 Billion $22.28 – $176.66 +465.07%

Merck $375.50 Billion $77.58 – $153.50 +42.98%

Under strong momentum, the 95th percentile of Edge stock rankings indicates MRNA shows positive price trends across all time frames.