ArriVent BioPharma shares plunged 47% Tuesday after the company’s most advanced drug candidate failed to meet the primary endpoint in a pivotal Phase 3 lung cancer trial, sharply reducing expectations for what had been one of the company’s biggest near-term opportunities. The stock closed at $15.09 after falling as much as 58% during the session, leaving shares down more than 27% for 2026.
The setback came from FURVENT, a 398-patient global trial testing ArriVent’s oral drug firmonertinib as an initial treatment for patients with advanced non-small cell lung cancer carrying EGFR exon 20 insertion mutations. Firmonertinib did not produce a statistically significant improvement in progression-free survival, or the amount of time patients lived without their cancer worsening, compared with platinum chemotherapy plus pemetrexed under the trial’s independent central review.
Patients receiving the higher 240-milligram dose had median progression-free survival of 11 months, compared with 9.5 months for the chemotherapy control group. The resulting hazard ratio was 0.75, but the confidence interval crossed 1 and the p-value was 0.0654, missing the study’s primary statistical threshold. The lower 160-milligram dose performed worse, with median progression-free survival of 8.4 months and a hazard ratio of 0.91 versus chemotherapy.
The higher dose did show evidence of antitumor activity. Its independently assessed objective response rate was 60%, compared with 33% for chemotherapy, while investigator-assessed progression-free survival also favored the 240-milligram dose. ArriVent said overall-survival data remain immature and currently show a trend toward improvement, but those secondary signals do not erase the failure of the trial’s prespecified primary endpoint.
FURVENT Miss Changes the Near-Term Firmonertinib Case
The magnitude of the stock decline reflects firmonertinib’s importance to ArriVent rather than a sudden deterioration in the company’s balance sheet. Firmonertinib has been ArriVent’s lead development program, and a significant majority of the company’s direct research and development spending has historically been tied to the drug. ArriVent licensed rights to develop and commercialize firmonertinib outside Greater China from Shanghai Allist Pharmaceuticals in 2021, paying $40 million upfront and issuing roughly 1.28 million shares. Its agreement also provides for as much as $760 million in additional clinical, regulatory and commercial milestone payments, along with royalties on future sales.
The Phase 3 result is particularly damaging because earlier studies had created expectations that an oral EGFR inhibitor could become a meaningful option for patients with less common EGFR mutations. Firmonertinib already has several approvals in China, including for some patients with exon 20 insertion-mutated disease, while the U.S. Food and Drug Administration had awarded the program Breakthrough Therapy and Orphan Drug designations. It remains investigational and unapproved in the United States.
The competitive standard has also advanced while ArriVent developed the program. In March 2024, the FDA approved Johnson & Johnson’s Rybrevant, or amivantamab, in combination with carboplatin and pemetrexed as a first-line treatment for advanced NSCLC with EGFR exon 20 insertion mutations. That means any future first-line path for firmonertinib would need to be assessed not only against the chemotherapy control used in FURVENT, but against a market where an approved targeted regimen is already available.
ArriVent has not said that development of firmonertinib is ending. Chief Executive Bing Yao said the company is reviewing the complete FURVENT dataset before determining the appropriate path for the drug. Safety did not appear to be the principal problem: Grade 3 or worse treatment-emergent adverse events occurred in 52% of patients receiving the 240-milligram dose, compared with 55% in the chemotherapy arm, and ArriVent reported no new safety signals.
Cash Gives ArriVent Time, but the Pipeline Now Matters More
ArriVent entered the FURVENT readout with enough capital to absorb a clinical setback without an immediate financing crisis. The company held $373.1 million in cash, cash equivalents and short-term investments at June 30 and said in August that those resources were expected to fund operations into 2028. It nevertheless remains a development-stage biotechnology company without approved U.S. products, reporting a $49.9 million net loss in the second quarter as research and development spending increased to $42.3 million.
That cash position now becomes more valuable because ArriVent has other programs that could determine how much of the valuation lost Tuesday can eventually be recovered. Firmonertinib is separately being tested in the Phase 3 ALPACCA study for patients with EGFR PACC mutations, a biologically distinct group from the exon 20 insertion population studied in FURVENT. Earlier Phase 1b data in PACC-mutated disease produced a median progression-free survival of 16 months at the 240-milligram dose, so the FURVENT failure should not automatically be treated as evidence that ALPACCA will fail as well.
ArriVent has also been expanding beyond firmonertinib. ARR-217, an antibody-drug conjugate targeting CDH17 in gastrointestinal cancers, had advanced into Phase 1b dose optimization by August, while ARR-002, a dual-targeting MUC16/NaPi2b antibody-drug conjugate initially aimed at ovarian and endometrial cancers, had received FDA clearance to begin human testing. The growing early-stage portfolio offers diversification, but those programs are substantially less mature than firmonertinib and are unlikely to replace a successful late-stage lung cancer program in the near term.
The next major issue is therefore not whether FURVENT contained any encouraging secondary data, but whether ArriVent can identify a credible regulatory or development route after missing the trial’s primary endpoint. More detailed FURVENT analysis, the maturation of overall-survival results and management’s decision on the program will determine how much value remains in the exon 20 opportunity. Beyond that, progress in ALPACCA will become increasingly important as investors reassess whether firmonertinib still has a viable path to becoming a meaningful commercial asset outside China.