Erasca, Inc. (ERAS) Shares Crater 48%, Wiping Out $2.8 Billion of Market Cap; Hagens Berman Investigating Intellectual Property Questions Regarding Lead Asset

SAN FRANCISCO, May 21, 2026 /PRNewswire/ -- Investors in Erasca, Inc. (NASDAQ: ERAS) saw the price of their shares tank  $9.25 (-48%) on April 28, 2026 after the company announced that it is facing a legal challenge to intellectual property claims for its lead product candidate (ERAS-0015).  The challenge is being waged by competitor Revolution Medicines (RevMed) and relates to RevMed's RMC-6236.

The news and severe market reaction have prompted national shareholder rights law firm Hagens Berman to open an investigation into whether Erasca may have misled investors about the viability of its ERAS-0015 intellectual property. The firm urges Erasca investors who suffered significant losses to contact the firm now to discuss their rights.

Visit: www.hbsslaw.com/investor-fraud/eras
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Erasca, Inc. (ERAS) Investigation:

Precision oncology company Erasca's ERAS-0015 is the company's investigational, oral, potentially "best-in-class" pan-RAS molecular glue under development to treat RAS-mutant solid tumors, including pancreatic ductal adenocarcinoma.

In the recent past, Erasca has favorably compared the equivalence of its ERAS-0015 40 milligram dose cohort to RevMed's RMC-6236 400 milligram dose cohort. In addition, as recently as March 12, 2026, Erasca assured investors of its ERAS-0015 intellectual property protection, and touted that its ERAS-0015 has "in-licensed one patent family from Joyo" that "includes one issued US patent, one pending US non-provisional patent application, one issued foreign patent, and thirteen pending foreign applications."

The company's assurances came into question on April 27, 2026. That day, Erasca disclosed that it received a letter from RevMed's legal counsel challenging the validity of Erasca's intellectual property claims.

In particular, RevMed claimed that "a third party misappropriated" RevMed's trade secrets in connection with ERAS-0015, Erasca's claims that ERAS-0015 is "substantially equivalent" to RevMed's RMC-6236 infringes on RevMed's patent, and that Erasca "improperly compared preclinical data of ERAS-0015 and RMC-6236 in public disclosures." RevMed demanded that Erasca immediately cease its "sale, selling, and importation of ERAS-0015 in the United States" for most purposes and from making any "deceptive and untrue comparative statements comparing ERAS-0015 and RMC-6236."

The market swiftly reacted, sending the price of Erasca shares down $9.25 (-48%) the next day. The move wiped out over $2.8 billion of Erasca's market capitalization in a single day.

"We're investigating whether Erasca may have intentionally misled investors about a potential moat in its particular highly competitive cancer treatment space," said Reed Kathrein, the Hagens Berman partner leading the firm's investigation.

If you invested in Erasca and have substantial losses, or have knowledge that may assist the firm's investigation, submit your losses now »

If you'd like more information and answers to other frequently asked questions about the Erasca investigation, read more »

Whistleblowers: Persons with non-public information regarding Erasca should consider their options to help in the investigation or take advantage of the SEC Whistleblower program. Under the new program, whistleblowers who provide original information may receive rewards totaling up to 30 percent of any successful recovery made by the SEC. For more information, call Reed Kathrein at 844-916-0895 or email [email protected].

About Hagens Berman
Hagens Berman is a global plaintiffs' rights complex litigation firm focusing on corporate accountability. The firm is home to a robust practice and represents investors as well as whistleblowers, workers, consumers and others in cases achieving real results for those harmed by corporate negligence and other wrongdoings. Hagens Berman's team has secured more than $2.9 billion in this area of law. More about the firm and its successes can be found at hbsslaw.com. Follow the firm for updates and news at @ClassActionLaw. 

SOURCE Hagens Berman Sobol Shapiro LLP