On May 31, Beijing Time (May 30, Chicago Time), the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting unveiled a major clinical breakthrough. The interim analysis of the pivotal Phase II ESAONA study evaluating asandeutertinib (TY-9591), a next-generation EGFR-TKI independently developed by TYK Medicines (02410.HK), a Hong Kong-listed innovative pharmaceutical company, as first-line treatment for patients with EGFR-mutated non-small cell lung cancer (NSCLC) and brain metastases, was presented as a Late-Breaking Abstract (LBA) in an oral session. The study, with Professor Yuankai Shi from the Cancer Hospital, Chinese Academy of Medical Sciences as its principal investigator, attracted great attention from global oncology experts, industry leaders, and capital markets due to its disruptive intracranial efficacy data, marking a major step forward for Chinese innovative drugs in the precision treatment of lung cancer brain metastases.

Fig. 1. ASCO LBA2007 (PI: Professor Yuankai Shi, Cancer Hospital, Chinese Academy of Medical Sciences)

 

Unmet clinical need is urgent. Asandeutertinib is precisely designed to tackle brain metastases in EGFR-mutant lung cancer.

EGFR mutations are the most common driver gene mutation in NSCLC. Brain metastases represent a particularly aggressive form of the disease, drastically shortening the survival of the patients and devastating their quality of life, underscoring a major clinical challenge and an unmet need.

Current third-generation EGFR-TKIs, while improving overall survival, have limited ability to penetrate and control brain metastases. Better intracranial efficacy and safety are urgently needed.

Asandeutertinib is a highly selective, next-generation, irreversible EGFR-TKI independently developed by TYK Medicines. As a differentiated deuterated analog of osimertinib, it offers unique pharmacokinetic advantages that significantly reduce toxic metabolite formation and has already shown excellent intracranial activity and tolerability in its early-stage studies, positioning it as a potential breakthrough for lung cancer patients with brain metastases.

 

Head-to-head pivotal Phase II study: robust design ensures high-quality evidence

ESAONA is an open-label, multicenter, randomized pivotal Phase II trial conducting a head-to-head comparison of asandeutertinib versus osimertinib, the current global first-line standard, in patients with EGFR-mutated NSCLC and brain metastases.

A total of 224 patients were randomized 1:1 to receive either asandeutertinib (160 mg once daily) or osimertinib (80 mg once daily), stratified by EGFR mutation type and number of intracranial lesions, ensuring balanced baseline characteristics. With its primary endpoints being intracranial objective response rate (iORR) and intracranial progression-free survival (iPFS), both assessed by Blinded Independent Central Review (BICR), the study comprehensively evaluated intracranial and systemic anti-tumor activity as well as safety and offered substantial clinical value due to its rigorous design and high-quality data.

 

Asandeutertinib outperformed osimertinib across all core endpoints, setting a new benchmark for treating brain metastases from lung cancer
As of December 15, 2025, with a median follow-up of 19.12 months, interim analysis showed that asandeutertinib was superior to osimertinib in both intracranial and systemic anti-tumor activity, with consistent benefits across all subgroups, demonstrating best-in-class potential.
1. A major leap in intracranial efficacy: 95.5% iORR marks a breakthrough

The control of intracranial lesions is the primary goal of treating lung cancer with brain metastases. The data from the ESAONA study set a new record for intracranial efficacy among current EGFR-TKIs.

BICR-assessed confirmed iORR was 95.5% in the asandeutertinib group, significantly higher than the 79.6% in the osimertinib group, representing an absolute difference of 15.62% with strong statistical significance (P=0.0004). Moreover, patients across all prespecified subgroups derived substantial benefit from asandeutertinib.

Fig. 2. Confirmed BICR-assessed iORR

Intracranial survival benefits were also impressive. Median iPFS was not reached in the asandeutertinib group, compared with only 17.51 months in the osimertinib group (HR=0.46, P=0.0020). Long-term follow-up data further showed that the 18-month and 24-month iPFS rates in the asandeutertinib group reached 75.24% and 61.56%, respectively, representing substantial improvements over the osimertinib group and effectively reducing the risk of intracranial disease progression.

Fig. 3. BICR-assessed iPFS survival curve

In the meantime, median iDoR was not reached in the asandeutertinib group, significantly better than 16.26 months in the osimertinib group (HR=0.50, P=0.0148), offering patients more durable intracranial tumor control. Furthermore, the iORR and iPFS data assessed by investigators using both RECIST v1.1 and RANO-BM criteria were highly consistent with the BICR-assessed results, further validating the stability and reliability of asandeutertinib’s intracranial efficacy.

Fig. 4. INV-assessed iORR and iPFS per RECIST 1.1

Fig. 5. INV-assessed iORR and iPFS per RANO-BM

2. Explicit superiority in systemic efficacy: a comprehensive upgrade in anti-tumor activity

Asandeutertinib also demonstrated significant clinical advantages in systemic anti-tumor efficacy. BICR-assessed ORR was 89.2% in the asandeutertinib group versus 77.9% in the osimertinib group (P=0.0301). Median PFS was not reached in the asandeutertinib group versus 17.22 months in the osimertinib group (HR=0.64, P=0.0473), indicating effective delay of systemic disease progression and potentially longer survival benefits for patients. Overall survival (OS) data remain immature, and follow-up is ongoing, with more favorable long-term survival outcomes expected in the future.

Fig. 6. BICR-assessed PFS survival curve

Manageable safety and good tolerability: dual advantages in efficacy and safety

Safety is the cornerstone for the clinical adoption and long-term use of innovative drugs. The safety data from this study showed that asandeutertinib had a manageable overall safety profile, with most adverse events being mild to moderate and effectively recovered after appropriate interventions and dose reductions.

The overall incidence of treatment-emergent adverse events (TEAEs) was comparable between the two groups. The incidence of grade ≥3 AEs in the asandeutertinib group was 49.5%, which was higher than that in the control group, but severe adverse reactions were effectively managed. Permanent discontinuation due to treatment-related adverse events (TRAEs) occurred in 4 patients in each group, demonstrating good tolerability of asandeutertinib, supporting its long-term regular use, and meeting the needs of long-term clinical treatment.

Fig. 7. Common TRAEs (incidence ≥10%) in both groups

 

Accelerated commercialization: poised to reshape the treatment landscape for lung cancer brain metastases

Based on the breakthrough positive data from the ESAONA study, asandeutertinib has demonstrated its core strengths including superior efficacy, a manageable safety profile, and significant differentiation, positioning it as a potential new first-line preferred option for patients with EGFR-mutated lung cancer and brain metastases.

The conditional New Drug Application (NDA) for asandeutertinib has been accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) and granted priority review, accelerating the listing process. If successfully approved, asandeutertinib will rapidly address the unmet need for more precise treatment of lung cancer brain metastases in China, offering a new therapeutic option for a broad population of patients with advanced lung cancer.

Looking ahead, TYK Medicines will continue to advance multiple clinical studies of asandeutertinib as monotherapy and in combination, further strengthening the clinical evidence system. More data will be disclosed in the future. Our company remains committed to addressing critical unmet needs in oncology, driving sustained innovation in next-generation kinase inhibitors, delivering high-quality, domestically developed innovative drugs to patients worldwide, and continuously unlocking its innovation value and growth potential in the capital market.

 

 

About Asandeutertinib
Asandeutertinib, developed by TYK Medicines, is an oral, new-generation, highly selective EGFR-TKI that exhibits high potency, ATP-competitive binding, and an irreversible mechanism of action. As a deuterated analog of osimertinib that’s already on the market, it exhibits distinct pharmacokinetic characteristics that significantly reduce the generation of the toxic metabolite AZD5104 (TY9591-D1), offering clear clinical advantages. It has shown significant efficacy, particularly in NSCLC patients with brain metastases and EGFR L858R mutation. TYK Medicines has initiated multiple clinical trials in China evaluating asandeutertinib as monotherapy and in combination for treating advanced NSCLC.

 

About TYK Medicines, Inc.

TYK Medicines, Inc. is an innovative biopharmaceutical company founded by MNC veterans in 2017, focusing on the discovery of new-generation Kinase Inhibitors to address the unmet medical needs in cancer therapy. TYK Medicines has a diversified pipeline with 10+ compounds including multiple phases from the PCC stage to Phase III clinical trials. The company is committed to providing patients with more effective and safer anti-tumor drugs.