How to Set a Biologic Strategy for Asthma, with Sara Assaf, MD

Each year at the American College of Chest Physicians (CHEST) Annual Meeting, the topic of biologic therapy seems to grow in frequency and significance — correlative with the burgeoning drug class itself, which has become a staple regimen in severe cases of most inflammatory airway diseases as of this year.

Though biologic conversations still lean toward forward-looking, pulmonary medicine has reached a time when they are very present and accessible for their drug class. The fun part is speculation; the important part is implementation.

In an interview with HCPLive during CHEST 2025 in Chicago, IL, this week, Sara Assaf, MD, assistant professor of pulmonary and critical care at the University of New Mexico School of Medicine, discussed her presentation titled, “How Do I Do It? Selecting the Right Biologic for the Right Patient with Severe Asthma.”

Assaf shared insights into her own practice’s strategies to prescribe, monitor, and assess biologic therapies in their patients with asthma. She also discussed how the rapidly developing industry of biologic therapy research and development has refined asthma care strategy, and where there remains some misunderstandings about this emerging drug class between her colleagues and patients.

The interview transcript was lightly edited for clarity.

HCPLive: When we talk about selecting the right biologic for the right patient, where does that start?

Assaf: Yeah, it's a great question. I think you have to take into consideration both the biologic and the patient, because factors at the level of the patients will come into play — like how much they exacerbate. Are they needing any systemic corticosteroids? What are their asthma scores, their quality of life, their spirometry? But you also have the biologic factors — things that are more related to biomarkers or phenotype that each biologic may address differently. Sometimes the dosing frequency of biologics can be a criterion to choose one over the other. Insurance costs [matter]. And patients can also be part of that decision making to decide if any biologic could be applicable for them, which one would be their preference.

HCPLive: How has competition in biologic drug class development shifted their role and priority in airway disease?

Assaf: I think as we have more options and as we learn more about it — and as we also know that you can have asthma with other concomitant comorbidities or conditions that a lot of those biologics are also approved for — we're gaining a better understanding or approach for which ones would fit better patients, depending on their clinical traits, their biomarkers, and their comorbidities.

So yes, we have more options, but those options can serve different purposes. Although they're all under type 2 inflammation, there are some nuances — and they're also ones that are not used for type 2 inflammation. So those options, maybe they're allowing for more targeted choices, depending on the patient characteristics, the comorbidities, and other factors, as we talked about.

HCPLive: What is your own prescribing strategy with patients who may benefit from biologic therapy?

Assaf: When we have our severe asthma patients in clinic, we try to phenotype them. We try to see what biomarkers they have predominantly — is it eosinophilia? Is it FeNO [fractional exhaled nitric oxide]? Are there any other factors?

I tend to make sure they're adherent to their inhaler regimen, and then try to see if there are any other comorbid conditions. Recently, I had someone with eosinophilic esophagitis. In that specific case, we were more directed towards anti-IL-4 [interleukin 4] receptor antagonist [biologics].

I think each case is different, and understanding the different clinical characteristics and trying to evaluate for what potential endotype and other factors helps us more with that algorithm or approach. But in a lot of cases, they might overlap, and you might still end up with multiple options that could be reasonable to offer for patients.

HCPLive: With which patients are we still not achieving the clinical benefit we potentially could with biologics?

Assaf: Of course, the low type 2 [inflammation patinets] has always been where we're trying to better understand [disease mechanism]. Now we have options. We have the anti-TSLP [tezepelumab] and I think maybe more to come as well. And sometimes, if they don't have the type 2 inflammatory markers, the steroid-dependent anti-IL-4 biologics can be also used. These are some of the patients that we need to better understand. And of course, the ones that already started on a biologic and don't necessarily respond well — [how are we] switching mechanisms and what class to switch to sometimes could be challenging to do.

HCPLive: What are the most common misconceptions of biologic therapy you see among your colleagues?

Assaf: I think one of the misconceptions — mostly at the level of patients and not my colleagues — is that once that you start [biologics], you can remove your inhaler therapy. [They think] that it's going to be a curative, and you don't need to take your inhalers anymore. That's something that we keep on stressing in clinics that once we're using this add-on therapy, that does not mean that you're not going to continue taking your daily regimen with inhaled steroid and any other controller.

And one of the important concepts that I think we also discussed in our session was remission, and that's something that we're learning more about. It's yet for us to understand once patients are doing better on biologics, what to step down as therapy — the biologic, the inhaler, none, or both. So, there’s more to learn from that perspective.