Lung Cancer New Drug Hopeful Plummets Over 20% Right After Market Close, 3 Trillion Won Vanished

Summit Therapeutics Inc. (NASDAQ: SMMT) closed at $16.22 on the Nasdaq on the 30th, plunging 22.13% in a single session and trimming its market capitalization to about $12.58 billion (approximately KRW 17.6 trillion).

The sharp share-price decline wiped out roughly $2.28 billion in market value (around KRW 3.2 trillion), and trading volume surged past 3.71 million shares, reflecting overheated activity and shaken investor sentiment.

Although there have been no major new negative announcements, investor concerns have been fueled by a series of analyst reports highlighting overvaluation and clinical risks. In March, Jefferies downgraded the stock from Buy to Hold and cut its price target from $42 to $15.

On the upside, in January the U.S. Food and Drug Administration formally accepted the company’s Biologics License Application for its lung cancer treatment, Ivonescimab combination therapy, setting a review completion target of November 14, 2026. This milestone underscores the continued mid- to long-term promise of Summit’s pipeline.

Based in Miami, Summit Therapeutics is an oncology-focused biotech firm co-developing Ivonescimab with China’s Akeso. The antibody therapy is a cornerstone asset aimed at the high-value anticancer market, including EGFR-mutated non-small cell lung cancer. After presenting notable survival-benefit data in its Phase III trial, the stock has historically spiked several-fold in short order, classifying it as a highly volatile name sensitive to clinical and regulatory developments.