Half a month ago, Tongyuan Kang Pharmaceutical announced that its independently developed TY-959 achieved the expected intracranial objective response rate (iORR) in a key phase II clinical trial comparing osimertinib as a first-line treatment for EGFR mutant lung cancer brain metastases, and claimed that TY-959 beat osimertinib head to head. Osimertinib's global sales reached 6.58 billion US dollars in 2024, making it AstraZeneca's second best-selling drug. However, AstraZeneca responded to this challenge by stating that they were unable to provide feedback on the existing information, which did not cause a big wave in the industry but instead raised many doubts.

Previously, Kangfang Biotechnology's PD/VEGFA dual antibody defeated K drug head to head in a phase III clinical trial, significantly prolonging the patient's PFS. On the day of the news release, Kangfang Biotechnology's stock price rose sharply. In contrast, the operation of Tongyuan Kang has been questioned. At present, Tongyuan Kang's claim of defeating Axitinib is based solely on iORR data, lacking OS data and sufficient patient numbers, which need to be validated through Phase III testing. And the deuterium substitution technology it adopts itself is controversial, regarded as a "micro innovation" to avoid the risk of research and development failure and save research and development time.

There are multiple motivations for Tongyuan Kang to release this message. In terms of the secondary market, the stock price rose 3.55% in advance on the trading day before the announcement was released. The second day of the announcement coincided with the adjustment of the Hong Kong Stock Connect target, and Tongyuan Kang was included in the Hong Kong Stock Connect, with a stock price increase of 16.18%. In addition, Tongyuan Kang plans to apply for conditional marketing with Phase II data, emphasizing the superiority of indications for EGFR mutant lung cancer brain metastasis, and is likely to apply for conditional approval of the lung cancer brain metastasis subgroup.

Deuteration technology, as a drug modification method, although has successful cases, there are also many problems. GSK once abandoned a deuterated drug due to concerns about drug resistance, and deuterated modifications may not completely avoid patent risks. Wu Yusheng, the founder of Tongyuan Kang, had limited information on tumor drug development in his past experiences, and other drugs under development in the company's pipeline were still in the early stages. TY-959 became the main pillar supporting its market value. Tongyuan Kang, which went public in the capital winter, is eager to realize the value of TY-959.

Compared to Doxofenib from Zejing Pharmaceuticals, the clinical design and market landscape of TY-959 are not optimistic. At present, the number of participants in its Phase II trial is too small, and relying solely on iORR is not convincing enough. Moreover, the competition in the third-generation EGFR TKI market is fierce, and if TY-959 cannot maintain its head to head victory over Axitinib in the Phase III data, it will be difficult for it to establish a foothold in the giant battle. The future of TY-959 is worth paying attention to. If "head to head defeating giants" is just a slogan without scientific evidence, then "head to head challenge successful" will become a kind of irony.