Drug development is a complex and challenging endeavor, marked by years of struggle, hard work, disappointments, and occasional triumphs. The story of Remedy Pharmaceuticals and our innovative stroke treatment, CIRARA, is no exception.
Each year, approximately 700,000 Americans suffer from ischemic strokes (some 14 million worldwide), with a particularly devastating subset classified as Large Hemispheric Infarctions (LHI). These strokes, which account for 10-15% of all ischemic strokes, are characterized by large infarcts (typically more than 70mL — approximately half a tennis ball) which frequently leads to massive brain edema, brain tissue shifts, herniation, and death.
Despite advancements like the clot-buster drug, rtPA, and mechanical clot removal through endovascular therapy (EVT), functional outcomes for LHI remain poor, and mortality rates high.
Remedy’s drug, CIRARA, targets a critical regulator of cerebral edema, the SUR1-TRPM4 channel. During an ischemic stroke, SUR1-TRPM4 channels become upregulated and open due to ATP depletion, leading to sodium influx, cell swelling, and disruption of the blood-brain barrier. By inhibiting this channel, CIRARA prevents the formation of this damaging and often life-threatening edema, potentially offering a new lease on life for patients suffering from LHI.
The journey of CIRARA began with the discovery of the SUR1-TRPM4 channel by Dr. J. Marc Simard at the University of Maryland School of Medicine. The founders of Remedy Pharmaceuticals licensed the technology to develop CIRARA from a scientific finding into a life-saving therapy.
Early trials (a Phase 2a pilot study and the Phase 2b study known as GAMES-RP) provided promising signals, demonstrating reduced mortality and improved functional outcomes in LHI patients.
In 2017, while Remedy was in the midst of planning a Phase 3 study, Biogen acquired CIRARA, and in late 2018 launched the Phase 3 CHARM study. Despite passing an interim analysis designed to determine whether proceeding was futile, Biogen’s strategic shift away from acute neurology led to the premature termination of the study in 2023.
Data from the CHARM study was transferred to Remedy Pharmaceuticals in 2024, at which point the company performed pre-specified and post hoc analyses. Pre-specified analyses of the CHARM study data revealed compelling results: CIRARA demonstrated statistically significant efficacy in patients with an NIH Stroke Scale (NIHSS) ≤20 (n=274) with an Odds Ratio of 1.8 (p=0.01), and LHI patients who also underwent EVT appeared to particularly benefit, with an Odds Ratio of 1.76 in favor of CIRARA, although this was not statistically significant.
Further analyses showed that in patients with ischemic lesion volumes < 125 mL, the Odds Ratio in favor of CIRARA was 2.15 (p=0.04). In patients with lesion volumes < 125 mL undergoing EVT, the odds ratio was 7.13 (p=0.01) in favor of CIRARA underscoring its substantial impact on functional outcomes which was accompanied by a dramatic 81% reduction in mortality without increasing severe disability.
Further post hoc analyses have now been performed and show that the Odds Ratio for achieving an mRS score of 0-3 (moderate disability or better) in patients with a lesion volume < 125 mL was 4.1 in favor of CIRARA (p<0.01). An mRS of 0-3 reflects moderate disability or less, which includes the ability to ambulate independently, a highly desirable outcome in LHI.
In the EVT population with a lesion volume <125 mL, the OR for achieving an mRS score of 0-3 was 18.5 in favor of CIRARA (p=0.03), indicating an even more dramatic improvement in functional outcomes, particularly in the ability to ambulate independently.
LHI is characterized by the development of life-threatening cerebral edema which causes the brain to shift past its center line, a phenomenon known as midline shift (MLS). MLS is associated with neurological deterioration and mortality, and MLS > 5 mm is considered a critical tipping point, indicating severe swelling and a higher risk of poor outcomes. In patients with lesion volumes < 125 mL who underwent EVT, CIRARA reduced MLS at 72 hours by 41% (3.4mm vs 5.8mm, p=0.02).
These findings were consistent with earlier results from the GAMES-RP study, reinforcing that, following a confirmatory study, CIRARA could become a game-changer in LHI treatment.
Thus, despite the setbacks, the story is far from over. With CIRARA squarely back in Remedy’s hands, we are ready to write the remaining chapters.
Looking ahead, Remedy is planning a pivotal Phase 3 trial that will confirm CIRARA’s effect in LHI patients with lesion volumes below 125 mL who undergo EVT. This carefully designed study seeks to build on the robust data already gathered and propel CIRARA towards regulatory approvals.
The estimated potential peak sales figure for CIRARA is approximately $2 billion. Between the patent portfolio developed by Remedy (both before the Biogen deal and after the asset’s return) and a new formulation patent developed by Biogen that is now owned by Remedy, the company has built a thicket of patent claims from multiple patent families, providing exclusivity by way of treatment method, dosing regimen, and formulation patents with expiry dates into the mid-late 2040s.
In the world of medicine, where each day can mean the difference between life and death, the stakes are incredibly high. So too is Remedy’s commitment. We have faced numerous obstacles and have emerged with a clear vision and an unwavering determination to see CIRARA through to its full potential. We are not just developing a drug for LHI; we are igniting hope of better days ahead for stroke patients and their families.
For now, we leave you with the words of Dr. Gregory W. Albers, Director of the Stanford Stroke Center, “After three decades of searching for an effective neuroprotective treatment, I believe we are finally on the verge of a breakthrough. CIRARA has more promising efficacy data than any of the previously tested agents.”
