Clinical Trial Evidence: A Closer Look at Geriatric Populations
While Fasenra (benralizumab) is approved for patients aged 6 and older with severe eosinophilic asthma, clinical trials specifically focused on the elderly population offer reassuring data. Analysis of pivotal studies for severe asthma revealed that 13% of participants were aged 65 or older, with 0.4% aged 75 or older. In these controlled studies, no significant differences in safety or effectiveness were noted between the geriatric and younger adult groups.
Key findings from asthma trials:
- The most common adverse reactions seen in the overall population, including older adults, were headache and pharyngitis.
- Injection site reactions were infrequent and occurred at a similar rate to placebo.
- A longer-term study showed a consistent safety and tolerability profile over a 5-year period, with no new safety signals emerging.
For adult patients with eosinophilic granulomatosis with polyangiitis (EGPA), 19% of participants in clinical trials were aged 65 or older. While formal conclusions on differential response were not possible due to limited numbers, the safety profile was consistent with that seen in asthma trials.
Real-World Data: Supporting Safety in the Elderly
Beyond controlled clinical settings, real-world studies provide valuable insights into how treatments perform in broader patient populations, including older adults who often have more comorbidities. A recent real-world study, published in July 2024, evaluated the efficacy and safety of benralizumab in elderly patients with severe asthma.
Notable results from the real-world study:
- In a subgroup of elderly patients (average age approximately 70), benralizumab proved effective and safe.
- Statistically significant improvements were observed in lung function and asthma control.
- Patients experienced reduced annual asthma exacerbation rates, and some were able to reduce their oral corticosteroid (OCS) dose.
- The study reported no adverse effects in the elderly subgroup during the 20 months of follow-up, though discontinuation rates due to side effects were slightly higher, possibly reflecting increased sensitivity to minor symptoms in this age group.
Comparison of Fasenra and Other Eosinophilic Biologics in Older Adults
Fasenra is one of several biologics used to treat severe eosinophilic asthma. While head-to-head comparisons in specific geriatric populations are limited, here is a general overview of Fasenra compared to other treatments based on overall trial data and mechanisms.
| Feature | Fasenra (Benralizumab) | Nucala (Mepolizumab) | Dupixent (Dupilumab) | Tezspire (Tezepelumab) |
|---|---|---|---|---|
| Mechanism | Targets and depletes eosinophils by binding to IL-5 receptor. | Blocks IL-5 cytokine, reducing eosinophil production. | Blocks IL-4 and IL-13, inhibiting multiple inflammatory pathways. | Blocks TSLP, inhibiting multiple inflammatory pathways upstream. |
| Target Population | Severe eosinophilic asthma (age 6+); EGPA (adults). | Severe eosinophilic asthma; EGPA; HES; CRSwNP. | Severe asthma (age 6+); Atopic Dermatitis; EGPA; CRSwNP. | Severe asthma (age 12+), including non-eosinophilic. |
| Dosing Frequency | Subcutaneous injection every 8 weeks (after initial 3 doses). | Subcutaneous injection every 4 weeks. | Subcutaneous injection every 2 weeks. | Subcutaneous injection every 4 weeks. |
| Geriatric Data | Safety and efficacy generally consistent with younger adults, but more sensitivity possible. | Adequate data in clinical trials; no specific concerns noted. | Adequate data in clinical trials; no specific concerns noted. | Data still emerging, but expected similar to other biologics. |
Managing Potential Side Effects in Older Adults
While the side effect profile of Fasenra appears consistent across age groups, older adults may be more sensitive or have comorbidities that require careful management.
- Headache: The most common side effect can often be managed with over-the-counter pain relievers (avoiding NSAIDs if asthma is a concern) and staying hydrated.
- Injection Site Reactions: These are typically mild but can be bothersome. Warming the prefilled syringe to room temperature before injection and rotating injection sites can help.
- Hypersensitivity Reactions: Though rare, serious allergic reactions can occur. Patients should be informed about the symptoms (rash, swelling, breathing problems) and advised to seek immediate medical help if they appear.
- Infections: Fasenra, like other biologics, affects the immune system. Older adults may be more susceptible to infections. Existing parasitic infections should be treated before starting Fasenra.
- Steroid Tapering: Patients should not abruptly stop systemic or inhaled corticosteroids after starting Fasenra. The process should be done gradually under a physician's supervision to prevent withdrawal symptoms or a flare-up of previously suppressed conditions.
Conclusion: Fasenra's Role in Older Adult Treatment
Based on available clinical trial data and real-world studies, Fasenra appears to be a safe and effective treatment option for older adults with severe eosinophilic asthma and EGPA. No overall differences in safety or effectiveness have been identified compared to younger adults, although some older individuals may have increased sensitivity to side effects. The key considerations for healthcare providers and patients include careful monitoring for side effects, vigilant management of comorbidities, and following a gradual, physician-supervised plan for any corticosteroid dose reductions. While more research with a larger geriatric population would be beneficial, the existing evidence is largely positive, providing confidence in its use for appropriate older patients.
How It Works: The Mechanism of Benralizumab
Fasenra works by targeting the interleukin-5 receptor alpha (IL-5Rα) on the surface of eosinophils and basophils. By binding to this receptor, benralizumab attracts natural killer (NK) cells, which triggers a process called antibody-dependent cell-mediated cytotoxicity. This process leads to the near-complete depletion of eosinophils in the blood and affected tissues, reducing inflammation and the frequency of severe asthma exacerbations. This targeted action helps avoid broad immune suppression associated with other treatments, contributing to its generally favorable safety profile. The effectiveness and tolerability of this mechanism have been demonstrated consistently in long-term studies.
