Sirius Therapeutics Re-files for Hong Kong IPO Amid Competitive Pressure Despite $800M CRISPR Deal

Holding a cooperation deal worth over $800 million, Sirius Therapeutics has once again knocked on the doors of the Hong Kong Stock Exchange (HKEX). After the initial prospectus expired, Sirius Therapeutics re-filed its listing application with the HKEX on March 31, seeking to go public on the Hong Kong stock market. As an innovative pharmaceutical company focused on siRNA therapies, Sirius Therapeutics has yet to commercialize any products and is projected to accumulate losses of nearly 600 million yuan by 2024 and 2025. However, a key collaboration has improved the company's financial position.

However, cooperative blood transfusion is not a long-term solution. The competitive pressure on its core product SRSD107 cannot be ignored. From the clinical advantages of siRNA drugs in terms of compliance to their commercial value, it remains uncertain whether Sirius Therapeutics can leverage the capital market to make its final leap.

　A Single Collaboration Boosts Book Profits

Sirius Therapeutics, like many innovative pharmaceutical companies seeking listing on the Hong Kong stock market, has not yet commercialized any products, and high R&D expenditures have kept it in a long-term loss. Financial data shows that in 2024 and 2025, Sirius Therapeutics' R&D expenditures were both 213 million yuan, with net losses of 342 million yuan and 255 million yuan respectively during the same periods, accumulating nearly 600 million yuan in total losses over the two years.

However, behind the losses, a strategic cooperation significantly improved Sirius Therapeutics' book profits and also provided some cash flow relief.

In May 2025, Sirius Therapeutics entered into a strategic collaboration with CRISPR Therapeutics to advance the development and commercialization of SRSD107. According to the prospectus of Sirius Therapeutics, CRISPR has paid a non-refundable upfront payment of $95 million, including $25 million in cash and CRISPR common stock valued at approximately $70 million at the time of issuance. Additionally, CRISPR holds exclusive rights to nominate two additional collaboration targets. The total amount of upfront and potential future milestone payments exceeds $800 million.

As the stock price of CRISPR Therapeutics rose, the fair value of the company's shares held by Sirius Therapeutics significantly appreciated. According to the prospectus of Sirius Therapeutics, in 2025, the fair value gain of financial assets measured at fair value with changes recognized in profit or loss amounted to 210 million yuan, primarily due to the change in fair value of CRISPR Therapeutics shares received as part of upfront payments in their collaboration. This nearly offset the R&D expenses for the year and directly drove the surge of Sirius Therapeutics' other income and gains to 232 million yuan in 2025, compared to only 9.788 million yuan in 2024.

According to the agreement between Sirius Therapeutics and CRISPR Therapeutics, the two parties will share costs and profits globally at a 50:50 ratio to advance the development and commercialization of SRSD107, including research funding support provided under a joint research plan. Sirius Therapeutics stated in its prospectus that its business development strategy is to retain full or substantial economic rights to core products and other key products, and the alliance with CRISPR Therapeutics AG is an example of this strategy.

Regarding this cooperation model, Deng Yong, a professor of Health Law at Beijing University of Chinese Medicine and doctoral supervisor, pointed out that in the short term, the upfront payment can effectively improve the financial situation of Sirius Therapeutics, alleviating the cash flow pressure caused by continuous losses. In addition, CRISPR Therapeutics has mature experience in technology development, global clinical advancement, and overseas commercialization, which can also help Sirius Therapeutics accelerate the progress of core product research and quickly enter the international market. However, in the long run, the equal profit-sharing model directly compresses the revenue space after the product launch. If the core product becomes a blockbuster drug, Sirius Therapeutics will lose half of its potential profits. Moreover, the joint decision-making mechanism may reduce the efficiency of R&D and commercialization, and future project collaborations may also divert the company's resources and energy.

Regarding related issues, Beijing Business Today reporter sent an interview letter to Sirius Therapeutics, and no response had been received as of press time.

　Concerns Linger Behind the Star Pipeline

From the product pipeline perspective, Sirius Therapeutics focuses on siRNA therapies. The core product and two key products disclosed in the prospectus target the currently popular disease areas of coagulation disorders, cardiometabolic diseases, and obesity.

Among them, the core product SRSD107 is a novel siRNA drug targeting coagulation factor XI, currently undergoing Phase II multi-regional clinical trials in Europe and China; the key product SRSD216 is a differentiated siRNA targeting Lp(a), currently conducting multi-regional Phase IIa trials simultaneously in China and the United States; another key product, SRSD384, is an INHBE-targeting candidate drug for obesity, which is currently advancing towards IND submission.

The core product SRSD107 is the most advanced product of Sirius Therapeutics. Although it has reached a cooperation with CRISPR Therapeutics, the competitive pressure is still significant. In the global competition landscape for FXI inhibitors, Novartis and Bayer's FXI inhibitors have already initiated global Phase III clinical trials, while Hengrui's SHR-2004 has also started Phase III clinical trials in China, all ahead of SRSD107 in terms of progress. Additionally, SRSD107 must also face competition from existing standard therapies such as apixaban, which has long established deep-rooted clinical usage habits and market barriers with annual sales exceeding billions.

However, SRSD107 still has its advantages. Phase I clinical trials have confirmed that a single subcutaneous administration of SRSD107 can reduce FXI levels by up to 95%, with effects lasting more than six months, offering significant advantages in terms of patient compliance. According to the prospectus, currently, there are only five siRNA drugs targeting FXI inhibitors in the global research and development pipeline. Sirius Therapeutics' SRSD107 ranks second in progress, just behind Ribo Biotech. However, how to convert its clinical data advantages into commercial leverage remains its core challenge after going public in Hong Kong.

Deng Yong pointed out that although SRSD107 stands out in terms of patient compliance and the FXI target exhibits a favorable safety profile with a low risk of bleeding, Sirius Therapeutics still needs to solidify its competitiveness with clinical data. This involves validating the product's advantages in compliance and safety, accumulating real-world evidence, and establishing itself as the best-in-class option. On the commercialization front, the company will rely on partnerships to expand into overseas markets while independently focusing on深耕 (deep cultivation) within Greater China, concentrating on rapidly scaling core indications like thrombosis prevention. Additionally, innovative payment solutions will be introduced to lower the threshold for medication access. Furthermore, the company will continue to optimize its siRNA technology platform, enrich its pipeline, build a product portfolio for cardiovascular chronic diseases, and establish channel barriers by leveraging specialized medical ecosystems, thereby achieving a breakthrough.