Moderna just became the first company in history to pass a Phase 3 trial with a personalized cancer vaccine. Every single dose is a different drug. Here's how it works. Surgeons remove the melanoma, then sequence the tumor's DNA and RNA. An algorithm compares it against the patient's healthy cells and picks up to 34 mutations unique to that one person's cancer. Those mutations get encoded into a custom mRNA strand, wrapped in lipid nanoparticles, and injected. The immune system reads the code, learns what that specific tumor looks like, and hunts down whatever cells surgery missed. Paired with Keytruda, which releases the brakes on T cells, the earlier trial showed a 49% cut in recurrence risk that held steady from year 3 all the way to year 5. The manufacturing is what pharma people can't stop thinking about. Drug factories are built to stamp out identical pills by the billion. This requires designing, synthesizing, and quality-testing a brand new drug for every patient, in weeks, from biopsy to injection. A batch size of one. Scientists have chased therapeutic cancer vaccines for 40 years. A handful got approved. None were mRNA, and none were built per patient. The Phase 3 covered 1,137 melanoma patients. Nine more trials are already running in lung, bladder, kidney, pancreatic, and gastric cancer. Moderna was worth $25 billion yesterday, down more than 85% from its COVID peak. Wall Street had priced mRNA as a one-pandemic technology. The repricing took one morning.