Real-World Outcomes of Febrile Neutropenia Among Patients With Breast Cancer or Non-Hodgkin Lymphoma

Weijia Wang, MSc, Sandoz, Princeton, discusses results from a study estimating the association of demographics, comorbidities, chemotherapy regimen and risk factors on the risk of developing febrile neutropenia (FN) in the first cycle among a cohort receiving pegfilgrastim prophylaxis.

These results were presented at the 2021 virtual National Comprehensive Cancer Network (NCCN) Annual Conference.

Transcript:  Hi, my name is Weijia Wang from Health Economics and Outcomes Research at Sandoz. Today, I want to talk to you about this poster, "Prophylactic Pegfilgrastim for Patients with Breast Cancer or Non-Hodgkin's Lymphoma," that we presented at the National Comprehensive Cancer network 2021Virtual Annual Conference.

We know that a lot of factors might come into play when assessing the risk of febrile neutropenia in a real-world setting. For example, we have age, we have sex, and comorbidities.

When comparing two existing treatment options such as prefilled syringes and on-body injector in terms of their effectiveness in decreasing the incidence of febrile neutropenia, it's very important for us to pay attention to the real-world factors involved rather than just reporting the crude rates of success. As such, we conducted this study to see exactly how this real-world risk factors affect the incidence of febrile neutropenia.

One thing I wanted to add before we can jump into the study details is that there's no Sandoz product involved in the study. This is a purely scientific exchange as we want it to generate knowledge that it can be used by the society and all the stakeholders.

First, let me tell you a little bit about the study design. In total, we identified 4,807 patients from a database called MarketScan Commercial and Medicare databases, which means that we include the patients covered by commercial insurance plans as well as the government Medicare plant.

Everyone in this study was diagnosed with breast cancer, or non-Hodgkin's lymphoma, receiving prophylactic pegfilgrastim from January 1st, 2017 to May 31st, 2018.

The first step is to make sure that everyone when initiating chemotherapy with no history of chemotherapy within the previous five years. Then we follow the progression for six months from the start of the chemotherapy to capture any febrile neutropenia events.

For the febrile neutropenia events, we applied three algorithm, including neutropenia, fever, and/or infection. We captured the demographic and clinical characteristics of these patients including most of all seven NCCN guidelines-defined risk factors that were related to febrile neutropenia events.

These risk factors including metastatic disease to the bone, baseline radiation, recent surgery, baseline liver dysfunction, baseline renal dysfunction, history of persistent neutropenia, and the last one which is age more than 65 years old. Finally, we conducted statistical analysis to compare the risk of neutropenia among patients with varying risk factors.

Now, we can jump into the results of the study. These risk factors were found to have a significant association with the incidence of febrile neutropenia. First, we looked at the main definition between the number of risk factor, for example, from three to zero.

We looked at that the incidence difference. We found that 14% of patients with three out of seven risk factors experienced febrile neutropenia compared to only 3% of those without any risk factors.

That translates into more than five times higher risk between these two groups. That means for a patient with three risk factors, they are five times more likely to experience febrile neutropenia than those without any risk factors.

Secondly, we looked at the people with increasing numbers of risk factors, what is the likelihood of experiencing FN compared to those with no risk factors, and we found that comparison was still significant higher.

Again, for the main definition, those with four or more risk factors were found 16 times more likely to experience febrile neutropenia than those without risk factors with 95% confidence interval from 2 to 170.

Yes, you heard me right. 170 is the higher upper limit of someone with four or more risk factors compared to those without in terms of the more likelihood to experience febrile neutropenia. Similarly, comparing three or more versus those without any, the odds ratio was six with a 95 confidence interval from 1 to 30. This pattern were consistent across all FN definitions.

To conclude, we could see that these results demonstrate the substantial increase in the risk of febrile neutropenia as more risk factors are present. Therefore, one can imagine the inaccuracies resulting from comparing treatment effects without looking at these risk profiles.

Additionally, we emphasized the importance of further real-world evidence is to compare the effectiveness of prefilled syringe against on-body injectors after adjusting aforementioned risk factors.

What we discussed today laid foundation work for the comparative-effective analysis. This comparison will serve as a substantial evidence for medical decision-making, especially when one product may offer significant cost-savings than the other.

To summarize everything and make inference, we wanted to say that real-world set of studies evaluated the comparative effectiveness of myeloid growth factors must apply appropriate statistical methods to mitigate bias by considering risk factors when adjusting these cohorts.

We hope that this can offer insights for everyone and show the importance of considering risk factors when conducting research. At the end of the day, our goals are to offer the right medicine to the right patients at the right time.

To learn more, you can read the full study at NCCN Annual Conference website or feel free to reach out to me. Thank you.

Wang W, Li E, Campbell k, et al. Febrile Neutropenia Outcomes Among Patients With Breast Cancer and Non-Hodgkin’s Lymphoma Receiving Pegfilgrastim Prophylaxis: A Real-World Analysis of Commercial and Medicare Claims From 2017-2018. Presented at: the NCCN 2021 Virtual Annual Conference; March 18-20, 2021. Abstract HSR21-073.

Weijia Wang is an employee of Novartis Inc. Weijia Wang was an employee of Sandoz during the time this study was conducted and presented at NCCN 2021.