Table 1 The spectrum of available immunotherapies
From: Cancer immunotherapy: the beginning of the end of cancer?
Strategy | Basic mechanism and major advantages | Major disadvantages | Reference |
|---|---|---|---|
Cytokines | |||
 IL-2 | -Stimulates the host’s immune system | -Low response rates -Significant risk of serious systemic inflammation | [1] |
 IFN-α | -Stimulates the host’s immune system -Durable responses (from a small subset of melanoma patients) | -Low response rates -High-dose toxicity | [1] |
Cell-based therapies | |||
 Vaccines | -Stimulates the host’s immune system -Minimal toxicity (e.g., sipuleucel-T) -Administered in the outpatient clinic | -Lack of universal antigens and ideal immunization protocols lead to poor efficacy and response | [6] |
 Adoptive cellular therapy | -Omits the task of breaking tolerance to tumor antigens -Produces a high avidity in effector T cells -Lymphodepleting conditioning regimen prior to TIL infusion enhances efficacy -Genetic T cell engineering broadens TIL to malignancies other than melanoma | -Restricted to melanoma -Safety issues, serious adverse effects, and lack of long lasting responses in many patients -Requires time to develop the desired cell populations -Expensive | |
Immune checkpoint blockade | |||
 Anti-CTLA-4 monoclonal antibodies | -Unleashes pre-existing anticancer T cell responses and possibly triggers new -Exhibits potent antitumor properties -Prolongation of overall survival | -Only a relatively small fraction of patients obtain clinical benefit -Severe immune-related adverse events have been observed in up to 35 % of patients | |
 Anti-PD1 and anti-PD-L1 antibodies | -Sufficient clinical responses which are often long-lasting -Therapeutic responses in patients within a broad range of human cancers -Reduced toxicity compared to anti-CTLA-4 antibodies | -Only a relatively small fraction of patients obtain clinical benefit | |
 Combination immunotherapy (immune checkpoint blockade as the backbone) | -Improvement of anti-tumor responses/immunity | -May lead to increases in the magnitude, frequency, and onset of side effects | |