Why Drug Developers Choose IgG4 for Monoclonal Antibodies? – Illiasul Ibad
Illiasul Ibad, Rheumatologist at Christian Medical College, posted on X:
”1․ Why are many therapeutic monoclonal antibodies built on the IgG4 framework?
2․ Understand basics
Biology of IgG4
• Least abundant IgG subclass
• Very weak complement activation
• Poor interaction with Fc receptors → almost no ADCC
Translation: IgG4 can block targets without collateral tissue damage.
3․ Fab-arm exchange
Natural IgG4 can swap half its arms → becomes “functionally monovalent.”
Good for tolerance in nature, but bad for drug stability.
Solution: scientists engineered the S228P mutation → no swapping, molecule stays stable.
4․ Why drug developers love IgG4
• Precise blocking, not killing
• Low inflammation risk
• Engineered stability
• Safe for long-term therapy
That’s why IgG4 is the backbone of modern antibody medicines – quiet, stable, effective.”

Stay updated with Hemostasis Today.
-
Oct 21, 2026, 18:13Wolfgang Miesbach: Hereditary Hemorrhagic Telangiectasia An Overlooked Bleeding Disorder
-
Oct 21, 2026, 17:55Gayatri Kotwal։ New Review on Anemia, Pain, and Nutritional Deficiencies in Cancer Patients
-
Oct 21, 2026, 17:40Tetsuzan Ron: Iron Deficiency Without Anemia Clinical Impact and Management
-
Oct 21, 2026, 17:29Amir Hossien Esfandiari։ The Association Between Viral Infections and Aplastic Anemia
-
Oct 21, 2026, 17:16Melissa Hollo: A Meaningful Step Forward for Women’s Health
-
Oct 21, 2026, 17:09Chipili Ng’onga: Have You Ever Seen a Result That Just Didn’t Make Sense?
-
Oct 21, 2026, 16:57Fabrice Cognasse: Celebrating the Next Generation of Platelet Research and Transfusion Medicine
-
Oct 21, 2026, 16:47Christabel Odeta: Treating Pediatric Cancer in Children With Sickle Cell Disease
-
Oct 21, 2026, 16:36Sharlene Haywood: Bringing Multidisciplinary Learning Into Nursing Practice