The Role of Avatrombopag in Interventional Oncology

Many patients require a transfusion to improve platelet counts and reduce risk of bleeding prior to undergoing complex interventional radiology procedures. However, medical treatment with avatrombopag, a thrombopoietin receptor agonist, may provide a novel alternative to transfusion for increasing platelet counts. In this Q&A, Riad Salem, MD, discusses an abstract¹ he presented on the potential use of avatrombopag for interventional radiology procedures. He presented the abstract at the Society of Interventional Radiology (SIR) meeting in Austin, Texas.

Can you tell us about your findings and why you chose to pursue the study?

This study was actually published elsewhere,² but we presented it because we think it is important for the interventional radiology community to be aware of the issues it highlights. For example, when performing biopsies, low platelet counts may be a risk factor for bleeding. To prevent bleeding, we usually transfuse platelets, but a platelet transfusion is not an ideal solution because it is costly, transient, and can cause tolerance to future reactions.

This is where avatrombopag (Doptelet) comes into play. It is an oral pill that is FDA approved and helps to boost platelet counts. Patients have optimized platelet counts after about 10 to 13 days of medical treatment, so we can plan the procedure around that time.

Have you personally used avatrombopag in your practice?

I have not used avatrombopag yet, but we wanted the IR community to be aware that it exists. The concept is only a few months old, the result of a recent randomized trial published in a high-impact journal.² I am hoping to incorporate it into my practice this year. At this time, I encourage my colleagues to look into the possibility of using avatrombopag in their practice, to follow the literature, and to reach out to the right people with questions.

Are there studies of avatrombopag that you would like to see specifically tailored to the IR space?

The registry model would be a good way to analyze and validate data that has already been published in the IR community. We perform many complex procedures where platelet counts of over 50 are mandatory, so we could very quickly generate a registry to validate this approach in those patients.

According to the data in the study you presented at SIR, how effective was avatrombopag? Did most patients respond adequately?

The primary endpoint was patients who did not need blood transfusions or a procedure to treat them for bleeding. The vast majority of patients treated with avatrombopag, around 70% to 80%, did not need those interventions, which is fantastic. In about 20% of patients, the drug was not enough to boost platelet counts, and those patients did need some platelets transfused.

Other than needing a transfusion, are there any downsides for patients who do not respond to the medical therapy?

Receiving avatrombopag does not prevent patients from later undergoing a transfusion, though those patients are slightly delayed in their biopsy as we wait for their platelet counts to increase. However, we usually prepare platelets in advance in case the medical therapy does not work, in order to minimize any delay to their biopsy.

What patients are best-suited for treatment with avatrombopag?

At this time, treatment with avatrombopag is best-suited to patients with chronic liver disease. Patients with liver cirrhosis tend to have low platelet counts, but considering this option for patients with chemotherapy-induced thrombocytopenia is of interest too.

Is there anything else that you would like colleagues to take away from this study at this point in time?

Those of us who perform many biopsies in patients with sick livers want to minimize risk to patients. In the spirit of sharing information, IRs should recognize that there are multiple tools to addressing low platelet counts. Avatrombopag has shown that it is significantly able to improve platelet count and is significantly able to decrease the need for blood transfusions and platelet transfusions. It meets a need that we have in IR. I think treatment with avatrombopag is an interesting approach to explore.

References

1. Allen LF, Aggarwal K, Vrendenburg M, Tian W, Salem R. Efficacy of avatrombopag (AVA) in optimizing platelet counts (PC) in chronic liver disease (CLD) patients with thrombocytopenia (TCP) undergoing interventional radiology (IR) procedures. Abstract presented on March 24, 2019 at the Society of Interventional Radiology Meeting in Austin, Texas.

2. Terrault N, Chen YC, Izumi N, et al. Avatrombopag before procedures reduces need for platelet transfusion in patients with chronic liver disease and thrombocytopenia. Gastroenterology. 2018; 155(3):705-718.