Table 1.

Approved cytokine monotherapies and cytokine-enhanced therapies for cancer.

Cytokine	Approved indications	Route of administration	References
IFN-α (2a or 2b)	Hairy cell leukemia; Chronic myelogenous leukemia; AIDS-related Kaposi's sarcoma	Intravenous injection Subcutaneous injection* Intramuscular injection*	(3)
IL-2	Metastatic renal cell carcinoma; Metastatic melanoma	Intravenous injection	(4, 5)
Talimogene laherparepvec (T-VEC)	Unresectable advanced melanoma	Intratumoral injection	(6)

^*Subcutaneous and intramuscular injections are local deliveries. However, they result in systemic cytokine distribution and are utilized in the clinic as systemic therapies.