Fighting cancer with immunotherapy has revolutionized treatment for some patients and therapies targeting the immune checkpoint molecules such as CTLA-4 and PD-1 have achieved durable responses in melanoma, renal cancer, Hodgkin's diseases and lung cancer.
First results in unresectable and metastatic melanoma patients treated with an anti CTLA-4 monoclonal antibody showed an unexpected 3-year overall survival of at least 25%.Lung cancer cells have multiple immunosuppressive mechanisms that allow to escape of the immune system and survive, however blocking CTLA-4 pathway with antibodies as monotherapy treatment have not achieved same results than in melanoma patients.
Many new treatment options in the last years, in particular targeted therapies (i.e. inhibitors of c-KIT, NRAS/MEK or BRAF) and immunotherapies (anti CTLA-4 and anti PD-1/PD-L1 antibodies), have changed the history of cutaneous melanoma.
Ipilimumab (a monoclonal antibody against CTLA-4) and nivolumab (a humanized antibody against PD-1) target these immune checkpoint pathways and are used for treatment of melanoma and an increasing number of other cancers.
Treatment with a combination of a proprietary formulation of coxsackievirus and either an anti-CTLA-4 or anti-PD-1 checkpoint inhibitor yielded a higher response rate in phase I testing for melanoma than any of these drugs given on their own.
Indeed, antibodies binding to CTLA-4, PD-1, or PD-L1 have shown remarkable efficacy, especially in combination therapies, for a number of cancers and have been licensed for the treatment of melanoma, nonsmall cell lung cancer, and renal and bladder cancers.
CAR-T cell-based therapies targeting CD19 can now induce durable remissions as well as prolong disease-free survival of patients with CD19 positive treatment refractory B cell malignancies and ICI-based therapies with humanized monoclonal antibodies against the T cell inhibitory receptors CTLA-4 and PD-1 as well as against the PD-1 ligand, PD-L1, can now achieve durable remissions as well as prolongation of life of a sizeable fraction of patients with melanoma and Hodgkin's lymphoma and non-small cell cancers.
Although immunotherapy with anti-CTLA-4 and anti-PD-1 agents has dramatically changed the treatment approach to cutaneous melanoma, its success in uveal melanoma has been much more limited.
Ipilimumab is a human monoclonal antibody that functions as a cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitor that is used to treat malignant melanoma.
Immunotherapy using checkpoint-blocking antibodies against targets such as CTLA-4 and PD-1 can cure melanoma and non-small cell lung cancer in a subset of patients.
Immune-checkpoint inhibitor (ICPI) drugs, which include antibodies against CTLA-4, PD-1 and PD-L1, have been shown to induce durable complete responses in a proportion of patients with particular efficacy demonstrated in both the first line and refractory setting in advanced NSCLC and melanoma.
Eligible patients were at least 18 years old, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, at least one measurable lesion per Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), unresectable stage III or IV melanoma (excluding ocular melanoma), and up to one previous systemic therapy (excluding anti-CTLA-4, PD-1, or PD-L1 agents).
Here, we show that Aire deficiency in mice expands the pool of CD4+ T cells capable of melanoma cell eradication and has additive effects with anti-CTLA-4 antibody in slowing melanoma tumor growth and increasing survival.
Six drugs including one CTLA-4 blocker (ipilimumab), two PD-1 blockers (nivolumab and pembrolizumab) and three PD-L1 blockers (atezolizumab, avelumab and durvalumab) are approved for the treatment of different types of cancers including both solid tumors such as melanoma, lung cancer, head and neck cancer, bladder cancer and Merkel cell cancer as well as hematological tumors such as classic Hodgkin's lymphoma.
Peritumoral injections of PlGF-2<sub>123-144</sub>-anti-CTLA4 (cytotoxic T lymphocyte antigen 4) and PlGF-2<sub>123-144</sub>-anti-PD-L1 (programmed death ligand 1) Abs delayed tumor growth and prolonged survival compared to the unmodified Abs in genetically engineered murine tumor models of melanoma and breast cancer.
- Exciting success with anti-PD-1/PD-L1 and anticytotoxic T-lymphocyte-associated protein 4 (CTLA4) checkpoint inhibitors has already been reported in melanoma and in lung and renal carcinomas.
BRAF-mutated melanoma benefit from both anti-BRAF and anti-MEK targeted therapies while triple-negative melanomas could benefit from novel anti-CTLA-4 and anti-PD-L1 immunotherapeutic approaches.