Syntara (SNT: $0.05) has released more mature data from its Phase IIb study of SNT‑5505 in the treatment of myelofibrosis, a type of bone‑marrow cancer. Enrolled patients had advanced disease, having been on ruxolitinib for between 5–89 months. The study began in December 2023 and reached its 16‑patient target by July 2024.
Eleven patients remained on treatment out to 24 weeks, and eight out to 36 weeks. Encouragingly, benefit continued past 24 weeks in those remaining on therapy—consistent with the mechanism of action of SNT‑5505, which gradually breaks down the fibrotic network in the bone marrow.
For a potential pivotal study, the anticipated primary endpoint is the percentage of patients achieving a 50% reduction in total symptom score (TSS50). Of the 11 evaluable patients after 24 weeks, eight (73%) had achieved TSS50, representing 50% of the original cohort. This result is notable given a median prior ruxolitinib treatment duration exceeding three years.
On spleen‑volume reduction (MRI‑measured), four of nine evaluable patients achieved at least a 25% reduction at week 24 or beyond; all four continued to see further reductions after week 24. SNT‑5505’s favourable safety profile distinguishes it from competing agents in development. Syntara CEO Gary Phillips emphasised that achieving these results in such an advanced patient population is particularly convincing.
Next steps include an FDA meeting to discuss pivotal study design: whether a single study will suffice; primary and secondary endpoints; study size (likely 300–350 patients); and treatment duration (six or 12 months). Phillips believes existing safety data support a Phase III transition. Recent fast‑track designation will facilitate streamlined regulatory interactions.
Patient-selection criteria will also require attention. The best spleen‑volume responders had been on ruxolitinib for less than two years, whereas some patients with 3–5 years of prior ruxolitinib therapy still achieved TSS50.
Ruxolitinib currently sells for US $150,000–$250,000 annually, but with patent expiry in 2028, prices are expected to drop—potentially enabling higher‑priced combination therapies such as SNT‑5505. Syntara continues partnering discussions but may self‑conduct Phase III, albeit with greater funding requirements.
As of March 31, Syntara held $18 million in cash, funding operations into H2 2026. The company’s market capitalisation stands at $85 million.
Bioshares recommendation: Speculative Buy Class A
CEO Gary Phillips will present at next month’s Bioshares Biotech Summit in Hobart.
Disclaimer:
Information contained in this newsletter is not a complete analysis of every material fact respecting any company, industry or security. The opinions and estimates herein expressed represent the current judgement of the publisher and are subject to change. Blake Industry and Market Analysis Pty Ltd (BIMA) and any of their associates, officers or staff may have interests in securities referred to herein (Corporations Law s.849). Details contained herein have been prepared for general circulation and do not have regard to any person’s or company’s investment objectives, financial situation and particular needs. Accordingly, no recipients should rely on any recommendation (whether express or implied) contained in this document without consulting their investment adviser (Corporations Law s.851). The persons involved in or responsible for the preparation and publication of this report believe the information herein is accurate but no warranty of accuracy is given and persons seeking to rely on information provided herein should make their own independent enquiries. Details contained herein have been issued on the basis they are only for the particular person or company to whom they have been provided by Blake Industry and Market Analysis Pty Ltd. The Directors and/or associates declare interests in the following ASX Healthcare and Biotechnology sector securities: Analyst MP: 1AD, ACR, AVR, CGS, CUV, CYC, DXB, IMM, LBT, MX1, OPT, NEU, PAB, PXS,RNO,SOM. These interests can change at any time and are not additional recommendations. Holdings in stocks valued at less than $100 are not disclosed.
