Issues in the assessment of the safety and efficacy of tenecteplase (TNK-tPA)

While thrombolytic agents have demonstrated improved mortality over the use of placebo, this has come at the expense of bleeding complications such as intracranial hemorrhage (ICH). Tenecteplase (TNK-tPA) is a novel thrombolytic agent engineered to improve upon the ease of use and safety of alteplase (t-PA). Given its longer half-life, TNK-tPA can be administered as a single bolus. The dosing of TNK-tPA has been weight optimized to enhance both safety and efficacy outcomes. Weight-optimized TNK-tPA dosing requires body weight estimation, which may introduce the potential for medication error. However, data from TNK-tPA clinical trials suggest that body weight estimates can err by up to 20 kg (44 lb) without an increased risk of ICH or death. Furthermore, the results of TNK-tPA clinical trials showed that even at the highest weight-optimized dosage of 50 mg, ICH rates were among the lowest reported in clinical trials of thrombolytics for acute myocardial infarction. In elderly female patients of low body weight, the use of weight-optimized TNK-tPA lowered the risk of ICH compared with the use of t-PA, expanding the potential use of thrombolytics to this high-risk patient population. Tenecteplase has demonstrated clinical equivalence to t-PA, but with a wider therapeutic margin of safety.