Inclusion Criteria:

• Clinically stable, in the opinion of the investigator
• Use of a cuffed, tunneled HD catheter
• HD prescribed at a BFR of ≥ 300 mL/min
• Baseline BFR (during the first 30 minutes of HD) of < 300 mL/min (using catheter lines in the customary direction, prior to any reversal of lines; see Section 3.1.2.a) at an arterial pressure of -250 mmHg (or at institutional guidelines for maximum negative arterial pressure, not to exceed 250 mmHg)
• Baseline BFR (during the first 30 minutes of HD) at least 25 mL/min below the prescribed BFR
• Demonstrated BFR of ≥ 300 mL/min (using catheter lines in the customary direction) at an arterial pressure in the range of 0 to -250 mmHg in at least one HD session in the 7 days prior to Visit 1
• Anticipated use of the same catheter for at least four consecutive HD sessions, on the same type and model of HD apparatus
• Able to have fluids infused at the volume necessary to instill study drug into the HD catheter

Exclusion Criteria:

• HD catheter with sustainable BFR of ≥ 300 mL/min following subject repositioning
• HD catheter inserted < 2 days prior to screening
• Evidence of a mechanical, non-thrombotic cause of HD catheter dysfunction (e.g., kink in the catheter or suture constricting the catheter), or dysfunction caused by known fibrin sheath
• Use of an implantable port
• HD catheter implanted in the subclavian vein
• Anticipated use of catheter for any other type of diagnostic or therapeutic procedure (i.e., other than HD) during the course of the study
• Previously treated in this study or any tenecteplase catheter clearance trial
• Use of any investigational drug or therapy within 28 days prior to screening
• Use of a fibrinolytic agent (e.g., alteplase, tenecteplase, reteplase, or urokinase) within 7 days prior to Visit 1
• Known to be pregnant or breastfeeding at screening
• HD catheter with known or suspected infection
• History of any intracranial hemorrhage, aneurysm, or arteriovenous malformation
• Use of any heparin (unfractionated or low molecular weight) within 24 hours prior to Visit 1, except for heparin used only during HD or for prophylaxis (e.g., heparin lock)
• Use of warfarin within 7 days prior to Visit 1, except for low-dose warfarin used for prophylaxis
• Initiation of or increase in dose of Plavix(R) (clopidogrel bisulfate) within 7 days prior to Visit 1
• Hemoglobin ≥ 13.5 g/dL if on erythropoietin
• Platelet count < 75,000/uL
• At high risk for bleeding events or embolic complications (i.e., recent pulmonary embolus, deep vein thrombosis, endarterectomy, or clinically significant right-to-left shunt) in the opinion of the investigator, or with known condition for which bleeding constitutes a significant hazard
• BFR of < 300 mL/min because of symptomatic hypotension
• Uncontrolled hypertension in the opinion of the investigator (e.g., systolic pressure > 185 mmHg and diastolic pressure > 110 mmHg)
• Known hypersensitivity to tenecteplase or any component of the formulation