Story perspectives

Revolution Sues Erasca Over Pancreatic Drug; Shares Split

4/29/2026

Summary

Revolution Sues

Revolution Medicines sued Erasca, Inc. for patent infringement over ERAS-0015 and demanded the company cease making, using, selling, importing it in the United States and stop statements.
Revolution’s shares rose 8.8% to $141.94 while Erasca’s stock fell 50% to $11.09, its single-day drop.
Erasca reported a 62% response rate for ERAS-0015 in pancreatic cancer patients, while a 66-year-old died from lung inflammation in the Phase 1 study after care was withdrawn.

Summary

Erasca Shows Shrinkage

The early trial showed tumor shrinkage in 62% of patients with advanced non-small cell lung cancer.
In the pancreatic cohort, 40% of participants experienced measurable tumor reduction.
The studies were conducted simultaneously in the United States and China, marking Erasca’s first Asian clinical activity.
Erasca CEO Jonathan Lim said the data are more definitive and expressed optimism about the drug’s potential.

Summary

Erasca Expands

Erasca launched monotherapy expansion and combination dose-escalation cohorts for ERAS-0015 in 2026 ahead of schedule.
Phase 1 data showed all 14 evaluable patients cut KRAS G12X allele fraction by at least 75 %, five fully, supporting recommended once-daily doses of 24 mg and 32 mg.
Erasca will evaluate ERAS-0015 with anti-EGFR panitumumab, with AURORAS-1 results due first half 2027 and ERAS-4001 data due second half 2026.

Summary

Erasca Shares Plunge

Erasca’s shares fell over 35% before the bell on Tuesday after company disclosed a fatal pneumonitis case.
JP Morgan analyst Anupam Rama and Clear Street analysts called the drop “materially overdone” and said the death was likely a one-off.
Evercore ISI analyst Jon Miller said pneumonitis incidence remains uncertain until full trial results are released.
ERAS-0015 shrank tumors in 62% of lung-cancer patients versus 38% daraxonrasib and yielded a 40% pancreatic-cancer response versus 29% comparator.

History

Historical Context

The U.S. Food and Drug Administration approved Amgen’s KRAS-G12C inhibitor sotorasib (Lumakras) in May 2020, marking the first targeted therapy for that mutation. Amgen reported $1.2 billion revenue from sotorasib in 2022, and the pivotal CodeBreaK100 trial showed a 37% response rate in non-small cell lung cancer. Erasca’s KRAS-G12X drug ERAS-0015 now shrinks tumors in 62% of NSCLC patients and 40% of pancreatic cancer cases, echoing the earlier breakthrough. These parallels have spurred rapid multi-regional trials and heightened stock volatility for biotech firms, prompting analysts like JP Morgan’s Anupam Rama to caution overvaluation.

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Revolution Sues

Revolution Medicines sued Erasca, Inc. for patent infringement over ERAS-0015 and demanded the company cease making, using, selling, importing it in the United States and stop statements.
Revolution’s shares rose 8.8% to $141.94 while Erasca’s stock fell 50% to $11.09, its single-day drop.
Erasca reported a 62% response rate for ERAS-0015 in pancreatic cancer patients, while a 66-year-old died from lung inflammation in the Phase 1 study after care was withdrawn.

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