A very new and promising immunotherapy approach to the treatment of cancer is the use of immune checkpoint inhibitors. These treatments work by “taking the brakes off” the immune system, so that the immune system becomes more effective in attack against cancer. Several different types of checkpoint inhibitors, targeting different checkpoints or “brakes” on immune cells, are currently in use. One of the most studied category of such check point inhibitors is the anti PD-1/anti PD-L1.
– Nivolumab (Opdivo®), made by Bristol-Myers Squibb (BMS), approved in 2015
– Pembrolizumab (Keytruda®), made by Merck, was approved in 2015
– Pidilizumab (CT-011), made by Cure Tech and sold to Medivation, in clinical trials
– Atezolizumab (MPDL3280A), made by Genentech/Roche, in clinical trials
– Durvalumab (MEDI4736), a PD-L1 antibody, made by AstraZeneca/MedImmune, in clinical trials
– Avelumab (MSB0010718C), made by Merck KGaA and P, in clinical trials
– BMS-936559, made by Bristol-Myers Squibb, no longer under clinical development
The good aspect is that although the above inhibitors are very new and most in clinical trials (which can only be accessed by a few), Nivolumab and Pembrolizumab are approved and as a result are accessible to everyone. Indeed, they are expensive. It costs about 2000-3000 euro every 2-3 weeks, assuming the dose indicated by the clinical trials and depending on the weight of the patient. Specifically, 100mg vial Opdivo costs about 1800euro in Germany. However, there are clinics in Germany such as that of Prof Nessulhut, who are using lower doses (which would cost about 1000 euro/month) while combining PD-1 inhibitors with Dendritic Cell vaccines. Such combinations may be more effective and with less chances for side effects so that in the end the patient would end up paying about 5500 euro/month and getting both a PD1 and a DC vaccine and possibly for shorter time to response, since the effectiveness is claimed to be better.
Note that many private clinics in Germany are now using (off label) PD1 therapy, since it is widely available.
Results from clinical trials:
For the PD1/PDL1 inhibitors, based on what I read the statistics seems to look like this: 20% partial an complete results, 40% stable diseas, 40% no response. However, this is a statistics over all cancer types and depending on the cancer type the partial and complete response may be much higher such as for melanoma, bladder, RCC, etc.
Also the results seem to be much better if the tumor immune cells are positive for PD-L1. In that case the response may even go up to 80%. Ref
Results from some anti PDL1 inhibitors in various cancers: http://www.mycancergenome.org/content/drug-class/pd-l1-inhibition-and-inhibitors/
Here is a recent (April 2015) good review on all the above including clinical results http://www.nature.com/bjc/journal/v112/n9/full/bjc2015124a.html#tbl2
From Nessulhut’s clinic I heard of success rate >50%.
Toxicities associated with checkpoint inhibitor immunotherapy: http://www.uptodate.com/contents/toxicities-associated-with-checkpoint-inhibitor-immunotherapy?source=see_link
(Immune-mediated pneumonitis has been reported with pembrolizumab and nivolumab, but is rare, with an overall incidence of less than 3 percent in over 400 patients in the initial clinical experience with this agent)
This therapy can lead to many side effects, most grade 1 or 2. Examples of side effects are diarrhea, thyroid issues, pneumonia, etc. However, these auto immune reactions can be controlled in most cases with medication that suppresses immune system (e.g. Corticosteroids). If the auto immune side effects are continuing the therapy is stooped.
Optivo side effects: http://www.rxlist.com/opdivo-side-effects-drug-center.htm
How to manage toxicity of Immunotheraphies with CTLA4 and anti PD1: https://content.webges.com/precimmuno/public/download_uploaded_media/pdf/37
VEGF inhibitors and anti-PD1: Combination immunotherapy + VEGF targeted therapy is the optimal systemic strategy for metastatic RCC http://www.niu.edu/kca/chicago/docs/d4-plimack.pdf
Note: Thalidomide is a good VEGF inhibitor
Obatoclax (X15-070 , GX15): Bcl-2 inhibitors are currently being evaluated in clinical studies for treatment of patients with solid tumors and hematopoietic malignancies. In this study we explored the potential for combining the pan-Bcl-2 inhibitor GX15-070 (GX15; obatoclax) with immunotherapeutic modalities. We evaluated the in vitro effects of GX15 on human T cell subsets obtained from PBMCs in terms of activation, memory, and suppressive function. Our results indicated that in healthy-donor PBMCs, mature-activated T cells were more resistant to GX15 than early-activated T cells, and that GX15 preserved memory but not non-memory T cell populations. Furthermore, GX15 increased the apoptosis of regulatory T cells (Tregs), profoundly downregulated FOXP3 and CTLA-4 in a dosedependent manner, and decreased their suppressive function. Treating PBMCs obtained from ovarian cancer patients with GX15 also resulted in increased CD8+ :Treg and CD4+ :Treg ratios. These results support preclinical studies in which mice vaccinated before treatment with GX15 showed the greatest reduction in metastatic lung tumors as a result of increased apoptotic resistance of mature CD8+ T cells and decreased Treg function brought about by GX15. Taken together, these findings suggest that when a Bcl-2 inhibitor is combined with active immunotherapy in humans, such as the use of a vaccine or immune checkpoint inhibitor, immunotherapy should precede administration of the Bcl-2 inhibitor to allow T cells to become mature, and thus resistant to the cytotoxic effects of the Bcl-2 inhibitor. http://www.jimmunol.org/content/early/2014/02/07/jimmunol.1301369.full.pdf
Vascular normalizing doses of antiangiogenic treatment reprogram the immunosuppressive tumor microenvironment and enhance immunotherapy http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491458/pdf/pnas.201215397.pdf
Aspirin could hold the key to supercharged cancer immunotherapy http://medicalxpress.com/news/2015-09-aspirin-key-supercharged-cancer-immunotherapy.html “Giving patients COX inhibitors like aspirin at the same time as immunotherapy could potentially make a huge difference to the benefit they get from treatment. It’s still early work but this could help make cancer immunotherapy even more effective, delivering life-changing results for patients.”
Immunomodulatory effects of cyclophosphamide and implementations for vaccine design. http://www.ncbi.nlm.nih.gov/pubmed/21611872 CTX markedly influences dendritic cell homeostasis and promotes IFN type I secretion, contributing to the induction of antitumor cytotoxic T lymphocytes and/or the proliferation of adoptively transferred T cells
T regulatory ( treg ) in tumors inhibit efficacy of immune checkpoint inhibitors http://m.cancerres.aacrjournals.org/content/early/2015/07/24/0008-5472.CAN-15-1082.abstract
TLR agonists such as Imiquimod or Immunomax: Currently a clinical trial combining topical imiquimod and PD-1/PD-L1 blockade for treating breast cancer cutaneous metastasis is also being planned in the University of Washington. The idea behind this combination is based on the fact that TLR agonists such as imiquimod are believed to induce e.g. IL-10, Treg, and PD-L1. As a result, this combination would address the induced PD-L1 http://journal.frontiersin.org/article/10.3389/fimmu.2014.00083/full
Radiotherapy: Immunotherapy and stereotactic ablative radiotherapy (ISABR): a curative approach? http://www.nature.com/nrclinonc/journal/vaop/ncurrent/full/nrclinonc.2016.30.html
ACAT1 inhibitors (such as Piperine, Honokiol, Omega3): https://www.cancertreatmentsresearch.com/cholesterol-cancer-acat-inhibition/
Neutralizing tumor acidic environment improves immune-targeting therapies Examples of approaches to reduce tumor acidic environment are discussed here (pH strategy). Another option that could help is DCA.
Anti-programmed cell death protein-1/ligand-1 therapy in different cancers http://www.nature.com/bjc/journal/v112/n9/full/bjc2015124a.html There is already evidence from at least one randomised trial that anti-PD-1 therapy is superior to chemotherapy in the treatment of patients with metastatic melanoma, and two anti-PD-1 antibodies, pembrolizumab and nivolumab, have been approved by the US Food and Drug Administration for the treatment of patients previously treated for metastatic melanoma. It is anticipated that approvals by drug regulatory bodies will be forthcoming in several cancers in the next months.
Neutrophils Regulate Humoral Autoimmunity by Restricting Interferon-Î³ Production via the Generation of Reactive Oxygen Species. http://www.ncbi.nlm.nih.gov/pubmed/26257170