FDA Grants Accelerated Approval to Bayer Hyrnuo for First Line HER2 Mutant Lung Cancer

Lung cancer remains the leading cause of cancer related deaths worldwide, and non small cell lung cancer accounts for more than 85 percent of all lung cancer diagnoses. Within that population, a small subgroup of patients carries activating mutations in the HER2 gene, also known as ERBB2, in the tyrosine kinase domain. These mutations are found in an estimated 2 percent to 4 percent of patients with advanced NSCLC and are associated with a poor prognosis and a higher incidence of the cancer spreading to the brain.

For years, treatment options for this biomarker defined group were limited, and physicians relied on chemotherapy or on therapies developed for other molecular targets. Bayer's sevabertinib, sold as Hyrnuo, entered the United States market in November 2025, when the Food and Drug Administration granted accelerated approval for adults with locally advanced or metastatic non squamous NSCLC whose tumors carry HER2 activating mutations and who had already received prior systemic therapy. The drug is an oral, reversible, small molecule tyrosine kinase inhibitor that selectively targets mutated HER2, including exon 20 insertions and point mutations, as well as mutated EGFR, while sparing wild type EGFR.

Bayer has said the compound was derived from its strategic research alliance with the Broad Institute of MIT and Harvard, and it estimates that up to 84,000 people are diagnosed with HER2 positive NSCLC globally each year. The second line approval was only a first step, and investigators have been running the Phase I/II SOHO-01 trial to test whether moving the drug earlier in the treatment sequence could deliver meaningful benefit for patients who have never received systemic therapy.

That question now has a regulatory answer. On September 9, 2026, the FDA granted accelerated approval to sevabertinib as a first line treatment for adults with locally advanced or metastatic non squamous NSCLC whose tumors have HER2 tyrosine kinase domain activating mutations, as detected by an FDA authorized test. The decision converts a previously treated only indication into a broader label covering treatment naive patients, and it sets up a direct competition with Boehringer Ingelheim's zongertinib, marketed as Hernexeos, which reached the first line setting earlier in 2026.

Key Facts

The FDA announced on September 9, 2026 that it granted accelerated approval to sevabertinib, from Bayer HealthCare Pharmaceuticals Inc., for adult patients with locally advanced or metastatic non squamous NSCLC whose tumors have HER2 tyrosine kinase domain activating mutations. The approval expands an earlier accelerated approval covering patients with the same biomarker who had received prior systemic therapy. The review was conducted under Project Orbis, with the FDA collaborating with the United Kingdom's Medicines and Healthcare products Regulatory Agency, and it used the Assessment Aid. The application was granted priority review, and sevabertinib also carries breakthrough therapy designation and orphan drug designation.

Efficacy was evaluated in SOHO-01, an open label, single arm, multicenter, multi cohort clinical trial registered as NCT05099172. The major efficacy outcome measures were confirmed objective response rate and duration of response, as assessed by blinded independent central review using RECIST version 1.1. Among 69 patients who had not received prior systemic therapy, the objective response rate was 75 percent, with a 95 percent confidence interval of 64 to 85. Bayer reported on September 9, 2026 that responses included complete responses in 6 percent of patients and partial responses in 70 percent.

Durability data were also presented. According to the FDA, 73 percent of responding patients had a duration of response of at least 6 months and 38 percent had a duration of response of at least 12 months. Medscape reported on September 10, 2026 that the oral HER2 inhibitor is the second drug approved in the United States for this indication, following zongertinib, from Boehringer Ingelheim Pharmaceuticals Inc., last year. The recommended dose of sevabertinib is 20 mg orally twice daily with food, taken until disease progression or unacceptable toxicity.

The prescribing information includes warnings and precautions for diarrhea, hepatotoxicity, interstitial lung disease or pneumonitis, left ventricular dysfunction, ocular toxicity, pancreatic enzyme elevation and embryo fetal toxicity. AllSci reported on September 10, 2026 that the most common adverse reactions, occurring in more than 20 percent of patients, were diarrhea, rash, stomatitis, paronychia, nausea and weight decrease. Continued approval may be contingent on results from the ongoing Phase III SOHO-02 confirmatory trial, registered as NCT06452277, which is evaluating sevabertinib against standard of care in treatment naive patients.

Analysis

The bigger picture here is that the first line HER2 mutant NSCLC field has moved from one option to a genuine rivalry in less than a year. Boehringer Ingelheim's zongertinib received accelerated approval in the first line setting in February 2026, based on the Beamion LUNG-1 study. Pharmaphorum reported on September 10, 2026 that the two drugs offer similar efficacy in their supporting trials, but that safety data appear to lend a competitive edge to Boehringer's drug, which seems to have lower toxicity overall and a lower rate of severe diarrhoea.

Commercial expectations remain modest. Pharmaphorum reported on September 10, 2026 that analysts at GlobalData predict Hernexeos will generate around 54 million dollars in seven major markets (France, Germany, Italy, Japan, Spain, the United Kingdom and the United States) by 2032, with Hyrnuo a little behind at 49 million dollars. Bayer has estimated that up to 84,000 people are diagnosed with HER2 positive NSCLC globally each year, so the eligible pool is far from trivial in absolute terms.

What this really means is that accelerated approval has become the default pathway for targeted oncology drugs in small biomarker populations, and both companies now carry the obligation to confirm their results. Bayer's continued approval depends on SOHO-02, while Boehringer is running Beamion LUNG-2. Until those trials read out, the first line label for both drugs rests on single arm response rate data rather than on overall survival. That is a familiar trade off in precision oncology, but it places a premium on real world evidence and on careful patient selection using an FDA authorized test.

Bayer reported fiscal 2025 sales of 45.6 billion euros and research and development expenses of 5.8 billion euros, so a product with forecast sales in the tens of millions is a strategic building block rather than an immediate revenue driver. For Bayer, the value of sevabertinib lies partly in proving that its alliance with the Broad Institute of MIT and Harvard can produce differentiated oral targeted therapies, and partly in establishing a presence in a lung cancer niche where it previously had no first line offering.

Why It Matters

For patients, the practical significance is a new first line option that can be taken as an oral pill at home. Sevabertinib is dosed at 20 mg twice daily with food, which avoids the infusion visits associated with some alternative regimens. The SOHO-01 cohort that supported the approval was small, at 69 treatment naive patients, but the 75 percent objective response rate, with complete responses in 6 percent of patients, is a striking figure. Patients with HER2 mutant NSCLC are predominantly women and tend to be younger and non smokers, a profile that often makes them candidates for targeted therapy and long term disease control.

The approval also matters because it expands the number of biomarker defined lung cancer populations with an approved first line targeted therapy. HER2 mutations occur in about 2 percent to 4 percent of advanced NSCLC cases. Xiuning Le, MD, PhD, associate professor of Thoracic and Head and Neck Medical Oncology at The University of Texas MD Anderson Cancer Center and lead investigator of SOHO-01, said the accelerated approval marks an important advance for treatment naive patients with HER2 mutated NSCLC who historically have a poor prognosis. Christine Roth, Bayer Executive Vice President, Global Product Strategy and Commercialization, said lung cancer remains the leading cause of cancer related deaths worldwide.

Regulators in other regions have also moved. Bayer said on September 9, 2026 that sevabertinib has been approved by China's NMPA and by Japan's Ministry of Health, Labour and Welfare. The FDA review itself was carried out under Project Orbis, with collaboration from the United Kingdom's Medicines and Healthcare products Regulatory Agency, a mechanism designed to give patients faster access to promising oncology drugs across multiple countries.

Next Up

Attention now turns to the confirmatory trials. Bayer's Phase III SOHO-02 trial, NCT06452277, is evaluating sevabertinib against standard of care in treatment naive patients, while Boehringer Ingelheim's Beamion LUNG-2 is pursuing the same conversion from accelerated to full approval for zongertinib. Positive readouts would solidify the first line positions of both drugs, while any weakness in either trial could narrow that drug's label or alter how the two are sequenced in clinical practice.

In the meantime, physicians will be watching real world safety data, particularly rates of severe diarrhea, hepatotoxicity and interstitial lung disease, because those are the events flagged in the sevabertinib label. The FDA authorized test requirement also puts a practical emphasis on broad and rapid molecular testing at diagnosis, since identifying HER2 activating mutations early is now the gateway to a first line oral option rather than a later line fallback.