A New Drug Targets One of Cancers Master Switches (Economist)

Summary

The "master switch" is KRAS, a RAS-family signalling protein that, when jammed "on" by a single mutation, tells cells to keep dividing. Daraxonrasib (Revolution Medicines, California) is an oral RAS inhibitor that, in a phase 3 trial in previously treated metastatic pancreatic cancer, nearly doubled median overall survival — 13.2 months vs 6.7 months on chemotherapy. The result drew a standing ovation at the ASCO meeting in Chicago. The article's larger claim: RAS mutations, considered "undruggable" for four decades, are now a tractable target across roughly a fifth of all cancers.

Key claims

• Population and result: patients with metastatic pancreatic cancer who had already received chemotherapy; median overall survival 13.2 months with daraxonrasib vs 6.7 months with chemotherapy (trade-press coverage of the ASCO 2026 plenary adds: ~500 patients randomised 1:1 across 59 sites, hazard ratio for death 0.40, grade ≥3 treatment-related adverse events 43.6% vs 57.5%).
• Not a cure. Resistance to targeted drugs is expected; the drug's promise is "months more life" when combined with other treatments.
• Why pancreatic cancer is so hard: usually symptomless, mostly diagnosed after spread, few patients survive beyond a year, and resistant to immunotherapy because the KRAS-driven tumour microenvironment is hostile to immune cells.
• Mechanism: KRAS is a binary on/off switch heavily involved in cell division; daraxonrasib inhibits it. Other work suggests KRAS inhibition may also remodel the tumour microenvironment, potentially making tumours more susceptible to immunotherapy — a hypothesis, not a trial result.
• Scope of the RAS family: RAS mutations occur in ~20% of all cancers, ~3.4m cases a year worldwide; discovered 1982. Candidate tumours for the same approach: some colorectal and lung cancers, and to a lesser degree endometrial, small-bowel and stomach cancers; in theory other RAS-driven cancers such as multiple myeloma; possibly paediatric neuroblastoma, where a different mutation disables a gene that normally brakes RAS.
• Regulatory path: expected to be fast-tracked in America and likely to become first-line therapy. (The Economist's 2026-08-29 column — It Now Seems Possible to Vaccinate Against Cancer (Economist) — reports FDA approval came on 26 August 2026.)

What is flagged as unproven

• The immunotherapy-sensitisation effect of KRAS inhibition is theory at this stage.
• Efficacy in other RAS-driven tumour types and in neuroblastoma is extrapolation; "more refined versions" and competitor drugs are anticipated but not reported.
• The Economist does not give the trial's name, size or hazard ratio; those numbers above come from trade coverage of the ASCO plenary and were not independently checked against the primary paper.

Wikilinks

KRAS Inhibitors — the concept page for RAS-family targeted therapy. Cancer Vaccines — the other immunotherapy thread the Economist paired with this one in August 2026. Lung Cancer Screening and Prevention — KRAS-mutant lung cancer is a named candidate for the same drug class. The Economist — Science & technology.

Captured-by trigger

Source file: raw/processed/Economist 2026-06-20 Science---Techn - A new drug targets one of cancers master switches.md.