On 27 August 2026, TYK Medicines (02410.HK) , a Hong Kong-listed innovative pharmaceutical company, announced that the independently developed next‑generation EGFR‑TKI asandeutertinib (TY‑9591, Kadasa®) had received conditional approval from China’s National Medical Products Administration (NMPA) for the first‑line treatment of adult patients with locally advanced or metastatic non‑small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) exon 19 deletions (19DEL) or exon 21 (L858R) substitution mutations, and with central nervous system (CNS) metastases.

This approval is based on the first interim analysis results from an open‑label, multicenter, randomized controlled pivotal Phase II study (ESAONA). The study was led by Professor Shi Yuankai from the Cancer Hospital of the Chinese Academy of Medical Sciences and presented as a Late‑Breaking Abstract (LBA) at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. A total of 224 patients were enrolled and randomized 1:1 to receive either asandeutertinib (160 mg QD) or osimertinib (80 mg QD), with stratification by EGFR mutation subtype and number of intracranial lesions to ensure baseline balance between arms. The primary endpoints were intracranial objective response rate (iORR) and intracranial progression‑free survival (iPFS) assessed by blinded independent central review (BICR).

 

Study Results

• Breakthrough in intracranial response – Asandeutertinib shows significant advantage in intracranial objective response rate

As of the data cutoff (December 15, 2025), the median follow‑up duration was 19.12 months. BICR‑assessed iORR showed superiority in the asandeutertinib group (95.5%) over osimertinib (79.6%), with an absolute difference of 15.62% and an extremely significant statistical difference (P=0.0004);

• Substantial iPFS benefit – Asandeutertinib reduces intracranial progression risk by 54%

Median BICR‑iPFS was not reached in the asandeutertinib group and only 17.51 months in the osimertinib group (HR=0.46, P=0.0020). Moreover, the 18‑month and 24‑month iPFS rates in the asandeutertinib group were 75.24% and 61.56%, respectively, showing substantially improved long‑term intracranial control over osimertinib;

• The benefit in both primary endpoints was consistent across all subgroups, demonstrating excellent efficacy consistency and best‑in‑class potential;
• Asandeutertinibdemonstrated superior systemic disease control across the board, along with a compelling overall antitumor efficacy;
• OS data remains im As of June 10, 2026, with a median follow‑up of 15.8 months, 69 events had occurred (data maturity of 30.8%), with an HR of 0.779 (P=0.3023) for asandeutertinib versus osimertinib;
• The safety profile is favorable, with treatment‑related adverse events generally tolerable, combining therapeutic benefit with a manageable safety profile.

 

Asandeutertinib was first granted the implicit approval for clinical trials in October 2019. In August 2023, the pivotal Phase II registration study (ESAONA) was formally initiated. In January 2026, asandeutertinib was granted priority review by the CDE; in February 2026, the NDA was formally accepted, and final approval was granted in August 2026. At present, two confirmatory registration studies are ongoing. We will leverage our strong clinical development capabilities to accelerate trial progress and ensure timely completion of these two confirmatory trials, so as to address unmet clinical needs in patients with lung cancer and bring benefits to a broader patient population.

 

ESAONA Study

The ESAONA study plans to enroll a total of 420 subjects. It comprises two parts: a pivotal Phase II study part and a confirmatory clinical study part. The first 220 evaluable subjects provided iORR data that met the prespecified superiority threshold, supporting conditional approval of asandeutertinib – this constitutes the pivotal Phase II part, which provided the data for the current NDA approval. Simultaneously, the study continues enrolling to reach 420 subjects. Once iPFS superiority over the control arm is achieved, it will support full conversion of the conditional approval. This latter part serves as the confirmatory study. As of August 2026, 390 EGFR‑mutant NSCLC patients with brain metastases have been enrolled in the ESAONA study. Based on current progress, the confirmatory portion of ESAONA is expected to be completed in the first quarter of 2030, with NDA submission planned for the third quarter of the same year.

 

FLETEO Study

In addition to ESAONA, another registrational Phase III study (FLETEO) is ongoing. FLETEO is designed to evaluate the efficacy and safety of asandeutertinib versus osimertinib as first‑line treatment in patients with locally advanced or metastatic NSCLC harboring EGFR‑sensitive mutations. The study plans to enroll 606 patients with EGFR L858R mutations, randomized 1:1 to receive asandeutertinib (160 mg QD) or osimertinib (80 mg QD) in 21‑day cycles. It is a randomized double‑blind, superiority design, with the primary endpoint being PFS assessed by BICR per RECIST v1.1. As of August 2026, 491 eligible patients have been enrolled. Based on current progress, the study is expected to be completed in the third quarter of 2029, with NDA submission planned for the first quarter of 2030.

Furthermore, the product’s clinical development plan also includes the development of asandeutertinib‑based combination regimens, as well as exploratory studies in patients with leptomeningeal metastasis.

 

 

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.