Sovateltide
An endothelin-B agonist approved in India for stroke
Sovateltide is a synthetic peptide modelled on endothelin-1 that selectively switches on the endothelin-B receptor. In rat stroke models it raised blood flow and encouraged neural repair, and in May 2023 India approved it, as Tycamzzi, for ischaemic stroke treated within 24 hours. The two trials behind that approval were small and run by its developer; it is not approved in the US.
What is it?
Endothelin-1 is best known as a powerful vessel constrictor acting through the endothelin-A receptor. Its other receptor, endothelin-B, does different things in the brain, and sovateltide was designed to hit only that one. In rats with middle cerebral artery occlusion, a 2024 meta-analysis of six studies found it lowered neurological deficits and improved motor performance at day 7, with smaller infarcts and more neural progenitor differentiation. All of that evidence is in rats.
The clinical programme ran in India. A 40-patient randomised, double-blind phase 2 trial added sovateltide to standard care within 24 hours of stroke; it was well tolerated, and more patients improved by two or more points on the modified Rankin Scale (60% against 40%, p = 0.05). The phase 3 trial randomised 158 patients, who received treatment about 18 hours after onset. At 90 days, the odds of independent function (mRS 0 to 2) were 2.75 times higher and 72.5% against 51.3% improved by at least two mRS points. Brain bleeding occurred in about 9% of both groups.
Both trials were funded by the developer, Pharmazz, and the phase 3 data were analysed by an author who is a company employee holding its patents and stock. The phase 3 trial excluded patients given thrombectomy and used imputation for missing 90-day data. Its authors say a multinational trial is needed for US approval, and ClinicalTrials.gov lists a 514-patient phase 3 that is recruiting.
Before stroke, the same molecule was tested in cancer as SPI-1620, meant to open tumour blood vessels and help chemotherapy reach the tumour. With docetaxel in 30 patients with advanced biliary cancer, it missed its target of five months' progression-free survival. Trials are also listed in spinal cord injury, neonatal hypoxic-ischaemic encephalopathy and Alzheimer's disease.
At a Glance
Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.
Published Research
Studies of sovateltide, from their PubMed abstracts.
Phase 3 in ischaemic stroke
In 158 randomised patients, mRS 0-2 at day 90 was more frequent with sovateltide (OR 2.75, 95% CI 1.37-5.57), as was NIHSS 0-5 (OR 2.67); 72.50% vs 51.28% improved by 2 or more mRS points; intracranial haemorrhage 8.75% vs 8.97%.
Phase 2 in ischaemic stroke
In 40 patients, sovateltide was well tolerated with no drug-related adverse events; mRS improvement of 2 or more points occurred in 60% vs 40% (p = 0.0519) and Barthel Index gains of 40 or more in 64% vs 36% (p = 0.0112).
First approval
Sovateltide was approved in India in May 2023 for cerebral ischaemic stroke within 24 hours of onset, and is in development for hypoxic-ischaemic encephalopathy, spinal cord injury and Alzheimer's disease.
Meta-analysis of rat stroke studies
Across six rat MCAO studies, IRL-1620 significantly lowered neurological deficit and improved motor performance at day 7; infarct volume and progenitor differentiation also improved; all included studies were in rats.
SPI-1620 with docetaxel in biliary cancer
In 30 patients with advanced biliary tract cancer, SPI-1620 plus docetaxel did not reach the target PFS of 5 months: median PFS 2.6 months, response rate 10.3%, overall survival 4.87 months.
Side Effects & Contraindications
Reported Side Effects
From the trials above.
Contraindications & Cautions
No US label exists; the phase 3 trial excluded these patients.
Legal Status
Sovateltide is approved in India and investigational elsewhere.
Frequently Asked Questions
?What is sovateltide?
A synthetic peptide analogue of endothelin-1 that selectively activates the endothelin-B receptor, approved in India in 2023 as Tycamzzi for ischaemic stroke treated within 24 hours.
?How strong is the evidence that sovateltide helps stroke patients?
Moderate at best: a 40-patient phase 2 and a 158-patient phase 3, both funded by the developer, with the phase 3 data analysed by a company employee. A larger multinational trial is recruiting.
?Is sovateltide available in the US?
No. It has no FDA approval, and its developers say a multinational trial will be needed for US approval.
?How does it differ from nerinetide?
Both are peptides tested in acute stroke. Nerinetide interferes with the neuronal protein PSD-95, while sovateltide activates endothelin-B receptors to raise blood flow and support repair.
References
- [other] PubChem CID 16130933, Sovateltide: formula C86H117N17O27, molecular weight 1820.9. Read October 3, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/16130933
- [fda] FDA. Drugs@FDA (openFDA): no application on record for sovateltide. Read October 3, 2026.
- [registry] ClinicalTrials.gov API v2, read October 3, 2026: NCT04047563 (phase 3, 158, completed), NCT04046484 (phase 2, 40, completed), NCT05691244 (phase 3, 514, recruiting), NCT05955326 (phase 4, 160, active), NCT04054414 (spinal cord injury, phase 2, recruiting), NCT05514340 (hypoxic-ischaemic encephalopathy, phase 2, recruiting), NCT04052737 (Alzheimer's, phase 2, 80, completed).
- [clinical-trial] Gulati A, et al. "Efficacy and Safety of Sovateltide in Patients with Acute Cerebral Ischaemic Stroke: A Randomised, Double-Blind, Placebo-Controlled, Multicentre, Phase III Clinical Trial." Drugs, 2024;84(12):1637-1650. PMID: 39542995.
- [clinical-trial] Gulati A, et al. "Safety and Efficacy of Sovateltide (IRL-1620) in a Multicenter Randomized Controlled Clinical Trial in Patients with Acute Cerebral Ischemic Stroke." CNS Drugs, 2021;35(1):85-104. PMID: 33428177.
- [pubmed] Keam SJ. "Sovateltide: First Approval." Drugs, 2023;83(13):1239-1244. PMID: 37486545.
- [pubmed] Moustakas D, et al. "The Effects of IRL-1620 in Post-ischemic Brain Injury: A Systematic Review and Meta-analysis of Experimental Studies." Neurocrit Care, 2024;41(2):665-680. PMID: 38724864.
- [clinical-trial] Kim R, et al. "Phase 2 study of combination SPI-1620 with docetaxel as second-line advanced biliary tract cancer treatment." Br J Cancer, 2017;117(2):189-194. PMID: 28632730.
Sources & Citations
Studies were read from their PubMed records and trial registrations from ClinicalTrials.gov, October 3, 2026.
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