Abstract TP4: Freezing Tenecteplase Aliquots Reduces Waste And Achieves Similar Door To Needle Times And Reperfusion Rates

Abstract

Objective: To determine the feasibility of using previously frozen tenecteplase (TNK) to treat acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Methods: This is a single-center proof of concept prospective study that was retrospectively analyzed. We began using freshly reconstituted TNK to treat AIS due to LVO in May 2020. In March 2022 we began dividing the 50mg vial of TNK into two frozen 25mg aliquots based on a previously published stability and bioactivity study comparing thawed TNK to freshly reconstituted samples. Our primary outcome was door-to-needle time (DTN) which was analyzed with a quantile regression specifying the median, which was adjusted for age, NIHSS and delays related to treating hypertension. Binomial logistic regression analyses were used to assess secondary outcomes of TNK recanalization rate prior to mechanical stroke thrombectomy (MST) and excellent reperfusion scores (≥TICI 2C) after MST in the fresh and previously frozen TNK groups. Results: Five frozen TNK vials (ten aliquots) had been created since implementation of freezing TNK. Seven previously frozen aliquots were thawed and used, while three aliquots expired and were discarded. We analyzed the seven previously frozen TNK aliquots against the sixty eight freshly reconstituted TNK vials used to treat acute ischemic stroke patients. Median DTN was similar between previously frozen, 41 (IQR, 27 - 53) and fresh TNK, 46 (IQR, 37 - 60), p = 0.12. There was no difference in the LVO recanalization rate prior to MST in previously frozen, 0 (0.0%) and fresh TNK, 2 (2.9%), p = 0.99. Patients undergoing MST achieved similar rates of excellent reperfusion in previously frozen, 4 (66.7%) and fresh, 30 (56.6%) TNK treated patients, Odds Ratio = 1.55 [95%CI, 0.25, 9.70], p = 0.64 Conclusions: It is feasible to freeze 50mg vials of TNK into two 25mg aliquots to use to treat acute ischemic stroke. We found similar DTN times, indicating that thawing the previously frozen TNK did not delay IV thrombolysis administration. Additionally, we found similar reperfusion rates prior to and after MST with freshly reconstituted and previously frozen TNK.