Removing a blood clot from a large brain artery via endovascular therapy (EVT), then injecting the clot-dissolving drug tenecteplase into the artery, has resulted in ischaemic stroke survivors being more likely to experience a better 90-day functional outcome when compared to those receiving standard clot removal, according to ANGEL-TNK study results presented as preliminary late-breaking science at the 2025 International Stroke Conference (ISC; 5–7 February, Los Angeles, USA).
“Endovascular treatment can help restore blood flow in a blocked large blood vessel,” said Xiaochuan Huo (Beijing Anzhen Hospital, Beijing, China), lead author of the study. “However, it might not improve blood flow in the smaller vessels and microcirculation in the area. This clinical trial tests whether delivering tenecteplase directly into the affected artery after endovascular treatment can break up blood clots in the small vessels and improve blood flow, reducing the amount of brain tissue that lacks blood supply.”
The ANGEL-TNK study—conducted at 19 centres in China—evaluated the safety and effectiveness of injecting tenecteplase directly into a large brain artery near where a clot was removed in order to restore blood flow. All 255 participants in the study (mean age, 70 years; 44.7% female) had anterior-circulation large vessel occlusions and were treated 4.5–24 hours after the last time they were observed to be well. According to the study protocols, 127 patients received tenecteplase after successfully undergoing EVT, while 129 received standard medical care (in the full analysis population for the final results) after successful EVT.
Disability—the study’s primary effectiveness endpoint—was measured via a score of 0–1 on the modified Rankin scale (mRS) at 90 days, while its primary safety-related endpoint pertained to brain bleeding within 48 hours of treatment or death from any cause within 90 days.
Analyses found that stroke survivors were 44% more likely to have an ‘excellent’ outcome (mRS 0–1) after 90 days if they received the tenecteplase injection and standard care after clot removal compared to receiving only standard care after clot removal (40.5% vs 26.4%, respectively). In addition, rates of brain bleeds in the two days after treatment were similar in those receiving tenecteplase (5.6%) and those receiving standard medical treatment (6.2%), and rates of death from any cause within 90 days were also similar with tenecteplase plus standard treatment (21.4%) versus standard treatment alone (21.7%).
“Intra-arterial tenecteplase after successful thrombectomy could improve the percentage of people with an excellent outcome. It could also improve the rate of large vessel occlusion stroke survivors who can return to society and live independently,” Huo said.
The researchers are following participants in ANGEL-TNK to assess one-year outcomes and, according to Huo, their results may someday be used to change treatment guidelines for stroke survivors who have undergone successful clot removal.
“We still need to directly analyse the individual data of participants in this and other trials—an individual meta-analysis—in order to release a high evidence-based recommendation,” he added.
The present study did not include patients treated with intravenous clot-busting drugs like alteplase or medications that reduce blood clotting, such as heparin and antiplatelets, during their endovascular procedures. According to the researchers, this means the benefits of intra-arterial tenecteplase shown in this study may not apply to people who receive those treatments.
