Moderna Plunges 20% After Cancer Vaccine Breakthrough Sent Shares Up 177%

Arcturus Therapeutics Holdings Inc. announced it will host a virtual presentation on Wednesday, September 23, 2026, at 4:30 p.m. ET covering the ARCT-810 Phase 2 clinical program for Ornithine transcarbamylase deficiency and the company's mRNA liver therapeutics platform. The company will issue a press release summarizing the presentation prior to the call. Marshall Summar, M.D., a founding member and Executive Committee member of the NIH UCD Consortium and a recognized expert in rare diseases and OTC deficiency, will participate in the presentation. ARCT-810 is an intravenously administered investigational mRNA therapeutic designed to express normal functional OTC enzyme in the liver of individuals with OTC deficiency, and it holds Orphan Medicinal Product Designation and an approved pediatric investigation plan from the European Medicines Agency, plus Orphan Drug Designation, Fast Track Designation and Rare Pediatric Disease Designation from the U.S. Food and Drug Administration. In Europe and the U.S., approximately 10,000 people have OTC deficiency.

BioNTech reported detailed Phase 3 data showing its investigational lung cancer therapy gotistobart nearly doubled median overall survival compared with standard chemotherapy. The shares traded around US$96.69, with a 30 day share price return of 3.87% and a 90 day share price return of 4.85%, while the 1 year total shareholder return declined 2.59% and the 5 year total shareholder return fell 71.40%. BioNTech now trades at roughly a 22% discount to analyst targets, with the most followed fair value view at $120.62 against the last close of $96.69. The company's pipeline includes multiple late stage Phase II and III trials for BNT327 and mRNA cancer immunotherapies in lung and breast cancers, supported by the planned CureVac acquisition. Risks to the bullish case include late stage oncology trial failures and prolonged COVID-19 vaccine demand weakness and related litigation.

Moderna and Merck reported positive results from the late-stage INTerpath-001 study of intismeran autogene (V940/mRNA-4157) in combination with Keytruda in patients with high-risk Stage IIB-IV melanoma whose tumors had been removed through surgery. The study met its primary endpoint of recurrence-free survival and a key secondary endpoint of distant metastasis-free survival, with the companies stating the improvements were statistically significant and clinically meaningful, though no numerical data were disclosed. INTerpath-001 marks the first positive phase III readout for an individualized neoantigen therapy and an mRNA-based cancer therapy, and five-year follow-up from the phase IIb KEYNOTE-942 study showed the combination reduced the risk of recurrence or death by 49% and the risk of distant metastasis or death by 59% versus Keytruda alone. Moderna and Merck are evaluating intismeran across nine phase II and phase III studies spanning multiple tumor types, including non-small cell lung cancer, bladder cancer and renal cell carcinoma, while Moderna's broader pipeline includes separate mRNA-based cancer antigen therapies, a T-cell engager and a cell-therapy enhancer. Moderna shares have skyrocketed nearly 400% year to date, outperforming the industry's 7% growth, and the stock trades at 23.44 times forward 12-month sales versus the industry average of 1.90 times.