China Approves Trastuzumab Deruxtecan Across HER2 Positive Solid Tumors

A Cancer Marker Opens a Wider Treatment Route

China's National Medical Products Administration has granted conditional approval to trastuzumab deruxtecan for adults with certain advanced solid tumors that show high levels of the HER2 protein. The decision, dated October 20 and announced by AstraZeneca on October 22, 2026, extends treatment across cancer types using a laboratory marker to identify eligible patients.

The medicine can be used alone for unresectable or metastatic solid tumors with HER2 expression scored IHC 3+, in adults who have previously received treatment or have no satisfactory alternative treatment options. Unresectable means a tumor cannot be removed by surgery; metastatic means cancer has spread to another part of the body.

Four phase II trials supported the approval. In the Chinese DESTINY-PanTumor03 study, 29 of 50 patients had a confirmed tumor response, a rate of 58%. Across the four studies, response rates in the specified HER2 positive groups ranged from 46.9% to 58%.

The approval gives patients with limited options another treatment route, including in cancers where HER2 targeted therapy has not routinely been part of standard care. Full approval depends on confirmation of clinical benefit in further trials.

Who Qualifies for the New Indication?

HER2, short for human epidermal growth factor receptor 2, is a protein on the surface of cells that helps regulate growth. Some cancers produce unusually large amounts of it, creating a target that certain medicines can recognize.

The new indication requires an IHC 3+ result. Immunohistochemistry, or IHC, uses staining to assess protein expression in a tumor sample. A score of 3+ identifies strong HER2 expression under the relevant testing criteria. Eligibility therefore depends on a tumor test as well as the patient's disease stage and treatment history.

The medicine, developed by Daiichi Sankyo and jointly developed and commercialized with AstraZeneca, is marketed internationally as Enhertu. At the time of the announcement, it had ten approved indications in China across areas including breast, digestive system, lung, gynecological and urinary cancers.

The new authorization was described as China's first approval of an antibody drug conjugate targeting HER2 across tumor types. Its practical reach comes from allowing the same biological feature to guide treatment in cancers originating in different organs.

Why Doctors Are Looking Beyond the Organ

Wu Xiaohua, chief expert in comprehensive gynecological cancer treatment at Fudan University Shanghai Cancer Center and a Chinese principal investigator of DESTINY-PanTumor03, said excess HER2 expression occurs in several cancers and is often associated with more aggressive disease and a poorer outlook. Describing the previous approach, he said:

In the past, HER2 targeted treatment mainly focused on specific tumor types.

Zhang Yanqiao, a professor at Harbin Medical University Cancer Hospital and director of the Heilongjiang digestive cancer diagnosis and treatment center, said patients with metastatic HER2 positive tumors often face limited choices once their disease progresses. This is especially relevant in cancers where HER2 targeted medicines have not been included in standard treatment.

The new approach adds a shared molecular feature to decisions traditionally organized around where cancer began. A cervical tumor and a bladder tumor remain different diseases, but strong HER2 expression can provide a common treatment target.

How the Medicine Delivers Its Treatment

Trastuzumab deruxtecan is an antibody drug conjugate, often shortened to ADC. It combines an antibody that recognizes HER2 with a cancer killing drug attached through a chemical linker.

The antibody binds to HER2 on a cancer cell. The cell takes in the attached medicine, allowing the drug component to be released inside. That component blocks topoisomerase I, an enzyme involved in handling DNA, and damages the cancer cell's ability to survive and multiply.

An FDA approval summary describes this mechanism and the earlier development of the medicine for lung cancer with activating HER2 mutations. It also records the United States approval in April 2024 for previously treated, unresectable or metastatic IHC 3+ solid tumors with no satisfactory alternative treatment options.

HER2 protein expression and HER2 mutations are different test findings. IHC measures protein in tumor tissue, while mutation testing looks for changes in the gene that provides instructions for making HER2. The new Chinese indication uses the IHC 3+ protein expression result.

What the Four Trials Found

The Chinese approval drew on DESTINY-PanTumor02, DESTINY-Lung01, DESTINY-CRC02 and DESTINY-PanTumor03. The evidence supporting this indication came from single arm studies, in which patients received the treatment without a concurrent comparison group receiving another therapy.

DESTINY-PanTumor02 included a subgroup of 111 previously treated patients whose tumors were assessed centrally or locally as IHC 3+. Independent central review confirmed responses in 57 patients, or 51.4%. Four had a complete response and 53 had a partial response. A complete response means all detectable signs of cancer disappeared on the assessments used; a partial response means the cancer shrank enough to meet the study's response criteria.

Among patients who responded in that group, the median duration of response was 19.4 months. Median progression free survival, the time patients lived without the cancer worsening or death, was 10.1 months. Median survival was 17.7 months. A median is the midpoint of the estimated distribution, rather than an outcome every patient experiences.

DESTINY-Lung01 included 17 patients with previously treated, centrally confirmed IHC 3+ non-small cell lung cancer. Nine responded, including one complete response, giving a response rate of 52.9%. Median response duration was 6.9 months, median progression free survival was 7.5 months and median survival was 12.5 months.

DESTINY-CRC02 included 64 patients with previously treated, centrally confirmed IHC 3+ colorectal cancer. Thirty had partial responses, a response rate of 46.9%. Median response duration was 5.5 months, median progression free survival was seven months and median survival was 15.1 months.

What the Chinese Study Adds

DESTINY-PanTumor03 provides evidence from 50 patients in China with previously treated IHC 3+ solid tumors. Their cancers included biliary tract, colorectal, lung, cervical, endometrial, ovarian, bladder and parotid gland cancers.

Independent review confirmed one complete response and 28 partial responses, producing the 58% response rate. Median response duration was 15.4 months, while median progression free survival was 15.7 months.

Median survival had not been reached at the analysis cutoff. This means the follow up data had not yet reached the point needed to estimate that midpoint.

The trial results show why response rate and response duration need to be considered together. In the lung and colorectal subgroups, response rates were 52.9% and 46.9%, while median response durations were 6.9 and 5.5 months. In the broader PanTumor02 group, the response rate was 51.4% and median response duration was 19.4 months. Each figure describes the patients and cancers in that particular study.

Testing Becomes Part of Access

HER2 testing is a practical step between a broader approval and patients receiving treatment. HER2 targeted medicines have been used in cancers including breast and bladder cancer, while routine HER2 expression testing has been less established in cancers such as lung and cervical cancer.

A multidisciplinary panel of Chinese experts addressed variation in testing through its HER2 testing consensus, published in Cancer Innovation on April 21, 2026. The consensus covers diagnostic strategies, testing methods and clinical applications across tumor types.

The panel identified the lack of standardized guidance for testing across cancers as a source of variation in clinical practice. A shared framework is intended to improve the consistency of assessment and the selection of patients for HER2 targeted treatment.

Lu Wenbin, vice president and head of development at Daiichi Sankyo China, said the company would work with clinical experts to expand HER2 testing and standardized care across more cancers. For patients, that makes the pathology result a central part of the treatment discussion, particularly in cancer services where HER2 expression testing has not been routine.

Lung Toxicity and Blood Effects Need Attention

A pooled safety analysis covered 4,146 patients across cancer types who received at least one dose of trastuzumab deruxtecan at 5.4 milligrams per kilogram. Severe or medically serious neutropenia, a shortage of white blood cells that help fight infection, occurred in 18.7%.

Other grade 3 or 4 reactions included anemia in 8.2%, fatigue in 7.4%, reduced white blood cell counts in 6.6% and reduced platelet counts in 5.4%. Platelets help blood clot. These effects make blood monitoring an important part of treatment.

Interstitial lung disease, or ILD, is another major risk. It involves inflammation or damage affecting lung tissue. In the pooled analysis, ILD led to permanent treatment discontinuation in 7.6% of patients. Fatal adverse reactions occurred in 0.9%, including fatal ILD in 0.7%.

The FDA summary describes how lung safety affected dose selection in the earlier DESTINY-Lung02 trial for HER2 mutated lung cancer. ILD or pneumonitis occurred in 6% of patients receiving 5.4 milligrams per kilogram, compared with 14% receiving 6.4 milligrams per kilogram, an eight percentage point difference.

The FDA selected the lower dose for that lung cancer indication because the study showed similar activity with reduced toxicity. The United States product label carries a boxed warning about ILD and pneumonitis. The trial population and pooled safety population cover different groups, so clinicians use the relevant prescribing information alongside each patient's circumstances.

Conditional Approval and the Next Evidence

The Chinese authorization is conditional, with full approval dependent on clinical benefit being confirmed in further trials. The next regulatory step therefore rests on additional evidence. No date for a confirmatory result or full approval was given in the announcement.

The regulatory and testing milestones span several years:

• December 20, 2019: The FDA first approved trastuzumab deruxtecan for a HER2 positive breast cancer indication.
• January 15, 2021: The FDA approved an indication for HER2 positive gastric or gastroesophageal junction cancer.
• August 11, 2022: The FDA granted accelerated approval for previously treated advanced non-small cell lung cancer with activating HER2 mutations.
• April 2024: The FDA approved treatment across eligible IHC 3+ solid tumors.
• April 21, 2026: The Chinese multidisciplinary HER2 testing consensus was published.
• October 20, 2026: China's regulator approved the new indication, followed by AstraZeneca's announcement on October 22.

The earlier American lung cancer review illustrates how follow up evidence fits into this process. In DESTINY-Lung02, the primary efficacy group of 52 patients receiving 5.4 milligrams per kilogram had a confirmed response rate of 58% and a median response duration of 8.7 months. The FDA required further clinical data through its accelerated approval process.

For the new Chinese indication, the immediate change is a treatment option organized around strong HER2 expression across several cancers. Its use will depend on reliable testing, clinical assessment, monitoring for serious adverse effects and the continuing collection of evidence.

Key Points

• China granted conditional approval to trastuzumab deruxtecan for eligible adults with unresectable or metastatic IHC 3+ solid tumors.
• The indication covers patients who have received previous treatment or have no satisfactory alternative treatment options.
• Four phase II trials supported the decision; 29 of 50 patients responded in the Chinese DESTINY-PanTumor03 study.
• HER2 expression testing is central to identifying eligible patients across cancer types.
• Serious risks include lung inflammation and reduced blood cell counts; pooled safety data included fatal ILD.
• Full approval depends on confirmation of clinical benefit in further trials.