In the global field of asthma treatment, precision immunotherapy is gradually becoming an important direction of development. In recent years, biologic therapies targeting the eosinophilic inflammatory pathway have continued to emerge, significantly changing treatment strategies for patients with severe asthma.

Among various targeted therapeutic approaches, the immune pathway centered on interleukin-5 (IL-5) has become an important target for the treatment of eosinophilic asthma.

Over the past decade, drug development around this pathway has followed a clear trajectory: from the earliest IL-5-neutralizing antibodies, to innovative mechanisms targeting the IL-5 receptor, and more recently to a new generation of therapies achieving ultra-long dosing intervals through antibody engineering.

As a Chinese pharmaceutical wholesaler focused on global innovative drug developments and cross-border pharmaceutical supply chains, DengYueMed continues to monitor emerging therapeutic trends, including asthma biologics, while also paying close attention to regulatory approvals, supply systems, and changes in patient accessibility across different global markets.

Eosinophilic Inflammation — The Biological Basis of Anti-IL-5 Therapy

Severe eosinophilic asthma is a subtype of asthma characterized primarily by eosinophil-mediated inflammation.

Patients with this condition typically experience persistent airway inflammation, frequent exacerbations, and inadequate response to conventional inhaled therapies.

In this process, IL-5 is a key cytokine that regulates the lifecycle of eosinophils. It is involved in:

● The production and differentiation of eosinophils

● Cell maturation and release

● Survival in peripheral blood and tissues

When the IL-5 signaling pathway remains persistently active, eosinophil levels increase, which can exacerbate airway inflammation. Therefore, inhibiting IL-5 or its receptor has become an important therapeutic strategy for controlling this inflammatory response.

IL-5 Neutralizing Antibodies: Mepolizumab Opens the Era of Precision Therapy

The clinical application of anti-IL-5 biologics began with monoclonal antibodies targeting IL-5 itself. These drugs directly bind to IL-5, preventing its interaction with the receptor and thereby reducing the production and activity of eosinophils.

Representative drugs in this category include Mepolizumab and other anti-IL-5 monoclonal antibodies.

Mepolizumab was among the earliest biologic therapies widely used for the treatment of severe eosinophilic asthma, marking the beginning of precision immune modulation in asthma treatment.

Clinical studies have shown that these drugs can significantly reduce asthma exacerbation rates and decrease patients’ dependence on systemic corticosteroids.

However, in terms of administration, these antibodies typically require dosing once every four weeks, which may still impose a certain treatment burden for long-term chronic disease management.

Targeting the IL-5 Receptor: The Mechanistic Innovation of Benralizumab

With deeper scientific research, investigators began exploring new intervention strategies—directly targeting the IL-5 receptor.

A representative drug of this approach is Benralizumab.Unlike IL-5-neutralizing antibodies, Benralizumab binds to the IL-5 receptor alpha subunit (IL-5Rα).

This mechanism provides two important advantages.

First, blockade of IL-5 signaling.

By occupying the receptor binding site, it prevents IL-5 from activating eosinophils.

Second, induction of cytotoxic effects.

Benralizumab can promote the elimination of eosinophils through antibody-dependent cellular cytotoxicity (ADCC) mediated by the immune system.

This dual mechanism enables more profound depletion of eosinophils in clinical settings.

In terms of dosing regimen, Benralizumab is administered every four weeks during the initial treatment phase and can subsequently be extended to once every eight weeks, thereby reducing treatment frequency.

Long-Acting Antibody Engineering: The Emergence of Depemokimab

In recent years, advances in antibody engineering have enabled researchers to extend drug half-life through molecular structure optimization, thereby reducing dosing frequency.

This direction has led to the development of a new generation of long-acting antibodies, among which Depemokimab has attracted considerable attention. Depemokimab still targets IL-5, but its antibody structure has been optimized to significantly prolong its duration of action in the body.

According to clinical study results, the dosing interval for this drug may reach once every six months.

For patients requiring long-term treatment for severe asthma, a longer dosing interval may translate into:

● Fewer visits to healthcare facilities

● Improved treatment adherence

● More stable long-term disease management

Recently, the National Medical Products Administration (NMPA) approved Depemokimab for marketing in China for the maintenance treatment of severe eosinophilic asthma.