TABLE 1.

Extent of eosinophil depletion with medical therapies

Drug	Target	Population	Eosinophil reduction
			Blood	Other
Benralizumab	IL-5R	Asthma [27, 28]	↓↓↓↓	↓↓↓ (airway),
				↓↓↓↓ (sputum)
		COPD [29]	↓↓↓↓	↓↓↓↓ (sputum)
		CRSwNP [30]	↓↓↓↓
		EGPA [31]	↓↓↓↓
		HES [32, 33]	↓↓↓↓	↓↓↓↓ (GI)
Mepolizumab	IL-5	Asthma [28, 34, 35]	↓↓↓	↓ (sputum)
		COPD [36]	↓↓↓
		CRSwNP [37]	↓↓↓
		EGPA [38]	↓↓↓
		HES [39]	↓↓↓
Reslizumab	IL-5	Asthma [40–42]	↓↓↓	↓↓ (sputum)
Dexpramipexole	Unknown mechanism	CRSwNP [43]	↓–↓↓↓↓#	↓↓↓↓ (nasal tissue)
		HES [44]	0–↓↓↓↓¶
Imatinib	Tyrosine kinase	CEL/HES [45]	0–↓↓↓↓¶
Systemic glucocorticoids	Glucocorticoid receptors	Asthma [46, 47]	↓–↓↓↓↓+

↓: <50% reduction; ↓↓: 50–79% reduction; ↓↓↓: 80–94% reduction; ↓↓↓↓: ≥95% reduction/near-complete depletion. IL-5R: interleukin-5 receptor; CRSwNP: chronic rhinosinusitis with nasal polyps; EGPA: eosinophilic granulomatosis with polyangiitis; HES: hypereosinophilic syndrome; GI: gastrointestinal; CEL: chronic eosinophilic leukaemia. ^#: approximately two-thirds of patients demonstrated >95% eosinophil reduction and the other one-third were partial responders (30–50% eosinophil reduction); ^¶: responses varied from profound reductions (e.g. eosinophil counts ≤10 cells·µL⁻¹) to no effect; ⁺: reductions in eosinophils are dose dependent and related to baseline levels [47].