The European Commission has revoked the EU marketing authorization for Hansoh Pharma’s lung cancer drug Aumseqa (aumolertinib) following a legal challenge from rival AstraZeneca.
The EC made the decision after the European Medicines Agency concluded that Hansoh partner SFL Pharma’s application from 2022 violated data protection rules by referencing AstraZeneca’s clinical data for Tagrisso, according to a Sept. 25 letter signed by the EC’s director-general for health and food safety, Sandra Gallina.
The EMA recommended approval for Aumseqa in November 2025 before the EGFR inhibitor was officially approved in February for the first-line treatment of EGFR-mutated non-small cell lung cancer, posing a direct threat to AZ’s blockbuster Tagrisso.
In a Sept. 27 announcement (PDF), Hansoh described the setback as “a procedural issue” that’s “not related to the quality, safety, efficacy or clinical value” of Aumseqa. According to Hansoh, the EC made the move after AZ sued the agency before the General Court of the EU.
The Chinese company said it intends to resubmit the market application to the EMA using the original data package as soon as possible, and that it reserves all rights to challenge the revocation.
“The Board is cautiously optimistic that a new marketing authorization can be obtained within a reasonably short timeframe,” Hansoh said, adding that “the EMA has indicated its willingness to shorten the standard assessment timeline.”
Despite its February approval in EU, Aumseqa has not generated any sales outside of China, where the drug received its first go-ahead in March 2020 under the brand name Ameile. The drug’s road to the EU market was long and winding, as reflected in the gap between its 2022 filing and 2026 approval.
Hansoh initially partnered with EQRx, whose dream of using China data to introduce cheaper cancer drugs to Western markets collapsed in 2023 after the FDA nixed that pathway. Hansoh, which did not have a presence in Europe, utilized SFL as the local face that inherited Aumseqa’s application.
Following its filing in 2022, Hansoh, at the request of European regulators, performed a European bridging study to complement its China data, which used first-generation EGFR inhibitor Iressa (gefitinib) as the comparator.
To establish Aumseqa’s profile, Hansoh relied on clinical data from Tagrisso’s Flaura trial, which were at the time still under EU data protection, according to the EC’s determination letter.
Citing past communication between SFL and the EMA, the EC said, “without the reliance on the FLAURA clinical study data, the application dossier did not provide an adequate and sufficient basis for extrapolating the safety and efficacy of Aumseqa from an Asian to a European patient population.”
As the EC explains, drugs approved in EU enjoy an eight-year data protection period from the time of market authorization, where other applicants cannot refer to the preclinical or clinical results for another application.
The protection around Tagrisso took effect on Feb. 4, 2016, and therefore was still in effect when Hansoh submitted its application. The protection expired in 2024, opening the door to a resubmission.
The kerfuffle in the EU comes as AZ faces pressure from Aumseqa and other domestic EGFR inhibitors in China.
With nearly $3.8 billion sales in the first half of 2026, Tagrisso remains the world’s best-selling EGFR inhibitor. But as AZ’s CEO Pascal Soriot noted on the company’s second-quarter earnings call in July, the EGFR king is under two major competitive threats.
“One in China, which is the multiplicity of EGFR [inhibitors] in the market and very competitive market,” Soriot said.
Meanwhile, Johnson & Johnson’s combination of Rybrevant and Lazcluze is also coming after Tagrisso’s first-line share following a head-to-head phase 3 win.