IDEAYA's Lung Cancer Drug Posts Striking Survival Data — But Can a Phase 1 Trial Carry a $3.5 Billion Valuation?

Shares of Ideaya Biosciences surged 8% to $39.00 in pre-market trading October 23, defying a broadly weaker market, after the company unveiled survival data for its experimental cancer drug that dramatically outpaces existing treatments for relapsed small-cell lung cancer — one of oncology's deadliest diagnoses.

A 17-Month Survival Figure Towers Over a Grim Standard of Care. The Phase 1 study, run by partner Hengrui in China, showed a median overall survival of 17.4 months in second-line SCLC patients, along with a 72.5% tumor response rate. For context, second-line chemotherapy for recurrent SCLC produces median survival rarely more than 12 months and usually less than six months.

Real-world data put second-line median survival at just 4 to 6 months. If these numbers hold in larger trials, Ideaya could be sitting on a transformative therapy.

The Competitive Race Against Amgen Is Intensifying. Ideaya's drug is an antibody-drug conjugate — essentially a guided missile that delivers a toxic payload directly to cancer cells. It competes with Amgen's tarlatamab, the first approved therapy targeting the same protein on SCLC tumors, which gained FDA accelerated approval in May 2024.

Tarlatamab posted a median survival of 13.6 months versus 8.3 months for chemotherapy in its Phase III trial. Ideaya's 17.4-month figure, though from a smaller, earlier-stage study, suggests a potentially superior profile that Wall Street will watch closely.

Phase 3 Plans Are the Real Test — and the Real Risk. Two randomized global Phase 3 trials are planned in previously treated SCLC and neuroendocrine cancers.

Ideaya aims to start the first pivotal trial by year-end, targeting both China and the U.S. The company still burns cash heavily — Q2 revenue was just $8.86 million while the net loss widened to $112.45 million — though it holds $829 million in cash , enough runway to fund late-stage development.

Analysts Were Already Bullish Before Today. Fifteen analysts rate the stock a "Strong Buy" with a consensus target of $52.38, roughly 34% above today's price.

The China study enrolled 122 patients — impressive for Phase 1 but a fraction of the thousands needed to secure regulatory approval. Investors betting on the $39 price are pricing in significant confidence that these early results will replicate at scale. The next inflection: third-quarter earnings on November 9 , where management will likely detail Phase 3 timelines and costs.