Clinical stage drug development company Syntara (ASX:SNT) is set to get a big boost in exposure within the blood cancer industry as it forges ahead with dosing patients in its Phase 2 clinical trial of SNT-5505 in combination with approved drug ruxolitinib.

SNT-5505, a pan-LOX inhibitor designed to target myelofibrosis, a bone marrow cancer where the current standard of care are JAK inhibitors, such as ruxolitinib. Patients diagnosed with myelofibrosis have an average life expectancy of just five years when treated with JAK inhibitors which largely mask symptoms, whereas SNT-5055 has shown early potential to modify the underlying disease. 

The first patient dosed with both treatments follows the FDA’s favourable review of the trial protocol and data from an earlier cohort, showcasing both an excellent safety profile and efficacy in patients unresponsive to JAK inhibitors. 

Through this combination arm of their existing Phase 2 clinical trials (named MF-101), Syntara will recruit up to 15 patients across Australia, South Korea, Taiwan, and the United States with full recruitment expected by June 2024. 

The open-label study is slated to provide interim data after six months of treatment, with 

Dr. Gabriela Hobbs, Assistant Professor of Medicine at Harvard Medical School, and Clinical Director of Leukaemia at Massachusetts General Hospital, keen to review after SNT-5505 was presented at the recent American Society of Hematology (ASH) conference in San Diego. 

“The data presented this week at ASH demonstrated that when used as a monotherapy in patients who have failed on a JAK inhibitor, SNT-5505 comprehensively inhibits the LOX enzymes, is well tolerated, and in some patients led to improvements in fibrosis and blood counts, which are encouraging signs of efficacy,” said Dr Hobbs. 

“Treatments like SNT-5505 that are well tolerated and can improve/stabilise blood counts and fibrosis are needed. In particular, SNT-5505 in combination with JAK inhibitor therapy has the potential to enhance the impact of JAK inhibitor treatment on symptoms, which is a vital area for future research.

“I eagerly anticipate reviewing data from this next study cohort in 2024.”

The market potential for an effective pan-LOX inhibitor in myelofibrosis is estimated at a conservative US$1 billion per annum. 

Being a market with such limited alternatives, there has been strong commercial interest from Big Pharma seeking to enter the market, or protect their existing share of that $1 billion per annum market. 

In 2021, Constellation Pharmaceuticals was acquired for USD $1.7bn after completing Phase 2 trials for their JAK inhibitor myelofibrosis treatment. It was followed again in 2022 when Sierra Oncology was acquired by GSK for USD $1.9bn after filing a New Drug Application with the FDA for momelotinib, a JAK-inhibitor treatment that has now been commercialised under the brand name Ojjaara. 

Having recently divested their legacy mannitol business, Pharmaxis in a strategic move that will save Syntara more than $14 million per annum in operating and regulatory expenses, CEO Gary Phillips is confident about the progress of drug development aiming towards FDA approval. 

“This study that commenced recruitment today is crucial in establishing the place for SNT-5505 in the treatment regimen of myelofibrosis patients,” he said. 

“The open label design enables us to assess the performance of SNT-5505 in real time and we are targeting a major interim data update at ASH 2024 that will also trigger follow up discussions with the FDA on the pivotal registration study design and support ongoing discussions with strategic partners.”