The accelerated approval moves Bayer’s oral therapy into previously untreated disease and intensifies its competition with Boehringer Ingelheim’s Hernexeos.
Key Takeaways
- The FDA expanded Hyrnuo into the first-line treatment of locally advanced or metastatic non-squamous NSCLC with activating HER2 tyrosine kinase domain mutations.
- Hyrnuo achieved a 75% objective response rate in 69 previously untreated patients from the Phase 1/2 SOHO-01 study.
- Bayer must confirm the drug’s clinical benefit in the randomized Phase 3 SOHO-02 trial.
Data Snapshot
| Item | Details |
|---|---|
| Product | Hyrnuo |
| Generic name | Sevabertinib |
| Company | Bayer |
| FDA action | First-line accelerated approval |
| Approval date | September 9, 2026 |
| Indication | Locally advanced or metastatic non-squamous NSCLC |
| Required biomarker | Activating HER2 tyrosine kinase domain mutation |
| Treatment setting | Previously untreated disease |
| Administration | Oral, twice daily |
| Supporting study | Phase 1/2 SOHO-01 |
| Evaluable patients | 69 |
| Objective response rate | 75% |
| Complete response rate | 6% |
| Partial response rate | 70% |
| Responses lasting ≥6 months | 73% of responders |
| Confirmatory study | Phase 3 SOHO-02 |
| Direct competitor | Hernexeos (zongertinib) |
The approval expands Hyrnuo from previously treated disease into the first-line setting. Continued approval may depend on confirmation of clinical benefit in SOHO-02.
What Happened
The US Food and Drug Administration granted accelerated approval to Bayer’s Hyrnuo (sevabertinib) for adults with previously untreated, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) harboring activating HER2 tyrosine kinase domain mutations.
Hyrnuo was initially approved in November 2025 for patients who had received prior systemic therapy. The expanded indication allows the oral tyrosine kinase inhibitor (TKI) to be used before chemotherapy or another systemic treatment.
The decision was supported by an untreated cohort from the ongoing Phase 1/2 SOHO-01 study. Among 69 evaluable patients, Hyrnuo produced a 75% objective response rate (ORR). Complete responses were reported in 6% of patients and partial responses in 70%; the one-percentage-point difference reflects rounding.
Among responding patients, 73% maintained their response for at least six months.
The FDA based the accelerated approval on response rate and duration rather than randomized evidence of progression-free or overall survival benefit. Bayer must verify clinical benefit through the Phase 3 SOHO-02 study, which is comparing Hyrnuo with standard treatment in previously untreated HER2-mutant NSCLC. (FDA Hyrnuo approval)
Why It Matters
HER2 mutations occur in approximately 2–4% of NSCLC. Although this represents a relatively small patient population, the disease has become a distinct market for mutation-guided oral therapies.
Many HER2 mutations in lung cancer are activating alterations within the receptor’s tyrosine kinase domain, particularly exon 20 insertions. They are biologically different from HER2 protein overexpression, which is commonly used to select patients for HER2 antibodies and antibody-drug conjugates.
Hyrnuo inhibits susceptible oncogenic EGFR and HER2 variants while showing selectivity over wild-type EGFR. Its lung cancer indication is therefore defined by an eligible HER2 mutation, not by HER2 expression alone.
Moving the drug into first-line treatment gives Bayer access to patients before they receive another systemic therapy. It also reinforces a broader shift in HER2-mutant NSCLC: targeted kinase inhibition is moving from salvage treatment toward the initial treatment decision.
The Science Behind Hyrnuo
Hyrnuo is designed to bind reversibly within the HER2 kinase region, reducing receptor phosphorylation and downstream RAS–ERK and PI3K–AKT signaling.
Want to understand how an activating HER2 mutation drives lung cancer—and how Hyrnuo interrupts that signal? Read my BP Science analysis.
How Hyrnuo Blocks Mutant HER2 Signaling in Lung Cancer
Hyrnuo Enters an Existing First-Line Market
Bayer is not the first company to bring an oral HER2 TKI into untreated disease.
Boehringer Ingelheim’s Hernexeos (zongertinib) received first-line FDA approval in February 2026 for unresectable or metastatic non-squamous NSCLC with activating HER2 tyrosine kinase domain mutations.
The two products now target closely overlapping patient populations. Fierce Pharma described Hyrnuo’s expanded indication as an escalation of the rivalry between Bayer and Boehringer, particularly because HER2 mutations account for only a small proportion of the broader NSCLC market. (Fierce Pharma Hyrnuo coverage)
Cross-trial results suggest substantial antitumor activity for both drugs, but their response rates cannot be treated as a head-to-head comparison. The trials differed in patient selection, follow-up and assessment conditions.
The competitive decision will therefore depend on more than initial tumor shrinkage.
| Competitive factor | Why it matters |
|---|---|
| Duration of response | Shows whether tumor shrinkage becomes sustained disease control |
| Brain metastasis activity | Central nervous system disease is an important challenge in HER2-mutant NSCLC |
| Safety and dose modification | Long-term tolerability affects first-line use |
| Mutation coverage | Individual HER2 variants may respond differently |
| Confirmatory evidence | Hyrnuo still requires verification of clinical benefit |
| Treatment convenience | Dosing burden can influence prescribing when efficacy appears similar |
A Strong Response Rate Does Not Settle the First-Line Contest
A 75% response rate is a strong result, but it came from a non-randomized cohort of 69 evaluable patients.
The current evidence shows that Hyrnuo can shrink tumors in a large proportion of biomarker-selected patients. It does not yet establish whether the drug improves progression-free or overall survival compared with an existing first-line regimen.
Safety will also influence adoption. Hyrnuo’s prescribing information includes warnings for diarrhea, hepatotoxicity, interstitial lung disease or pneumonitis, ocular toxicity and pancreatic enzyme elevation.
SOHO-02 will therefore carry more weight than a routine post-approval commitment. It must show whether the response signal translates into durable clinical benefit in a randomized first-line population.
BP View
Hyrnuo’s approval confirms that HER2-mutant NSCLC is becoming a first-line targeted-therapy market rather than a later-line niche.
The biological rationale is clear. If a tumor depends on an activating HER2 mutation, suppressing that driver before broader systemic treatment may provide more direct tumor control. The SOHO-01 response rate supports this strategy.
Bayer’s commercial challenge is differentiation. Hernexeos already serves a closely overlapping population, while Hyrnuo remains under the conditions of accelerated approval. A similar headline response rate will not establish a preferred position on its own.
The decisive evidence will come from response durability, brain metastasis activity, tolerability and the randomized SOHO-02 trial. These factors will determine whether Hyrnuo becomes a leading first-line option or one of two closely competing HER2 TKIs.
The approval validates Hyrnuo’s entry into first-line treatment, but durability and clinical usability will decide its position.
Related Post
HER2-directed therapies are also moving earlier in other tumor types, although their mechanisms and biomarker requirements differ.
Read my previous news analysis of Jazz Pharmaceuticals’ Ziihera approval in first-line HER2-positive gastroesophageal cancer.
About BP
Biopharma Perspective provides independent analysis of pharmaceutical and biotechnology news, connecting clinical data, regulatory decisions and competitive strategy.
Have a question about my analysis or another angle you would like to discuss? Leave a comment—I’d be happy to hear your thoughts.
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