Project Summary
Indwelling central venous catheters (CVCs), including peripherally inserted central catheters (PICCs) as well
as implantable venous access ports, are commonly used for drug treatments or supportive care in a variety of
disease conditions; however, central lines carry a risk of complications, including catheter-related infections
and catheter-related thrombosis (CRT). Several risk factors can contribute to CRT including underlying
diseases, many of which are conditions in which CVC placement is critical to patient care. For example,
cytotoxic chemotherapy to treat cancer can create a hypercoagulable state that increases CRT risk. While both
cancer and cancer directed therapy impart thrombotic risk, some also increase the risk of bleeding, including
myelotoxic drugs. At present, antithrombotic drugs are not used for CRT prevention in cancer patients due to
hemostatic impairment concerns and lack of efficacy data. Since CRT can have localized (device failure) or
secondary (vessel occlusion, embolization) complications, an important unmet need exists for safe and
effective CRT prevention in patients who need CVC placement. This SBIR Fast Track project directly
addresses this critical need by developing a unique contact activation targeting antithrombotic and
antiinflammatory agent, AB023 (gruticibart), to prevent CRT. We have recently conducted a small investigator-
initiated phase 2 clinical study in cancer patients with CVCs to evaluate whether this approach may be safe
and effective (NCT04465760). In this exploratory study, we found only 1 in 8 (12.5%) patients developed early
CRT detected via ultrasound after AB023 administration. In a parallel observational study, we found that 4 in
10 (40%) cancer patients with a CVC had early CRT detected via ultrasound. Our early clinical safety data
from this trial and from another trial in end stage renal disease patients on hemodialysis (NCT03612856)
suggests that AB023 is safe in medically complex patient populations, with no drug-related adverse events
observed in 42 treated individuals. During this Phase I/II SBIR project, we propose to conduct a powered,
randomized, placebo-controlled, double blind clinical trial to evaluate the safety of CRT prevention in cancer
patients who otherwise would not receive thromboprophylaxis. AB023 specifically targets prothrombotic
coagulation factor XI (FXI) activation by factor XII (FXII), without inhibiting hemostatic feedback activation of
FXI by thrombin. Therefore, AB023 is unique and has the potential to be exceptionally safe among other
investigational FXI/FXIa targeting drugs in development. However, it is not yet entirely certain that blocking the
FXI/FXII interaction has no unforeseen adverse effects on hemostasis. Therefore, as a long-term development
strategy, we will also determine the potential utility of several drug reversal approaches to terminate the
anticoagulant activity of AB023. Achievement of our critical milestones include: Aim 1- Identify one effective
reversal or bypass agent for AB023, and Aim 2- Demonstrate that a single dose of AB023 is safe and reduces
early CRT when administered to cancer patients at the time of CVC placement. Success of the proposed
research will prompt subsequent definitive trials of AB023 to safely prevent CRT.