Clinical Development Of Immunotherapy Research Articles

Advances in immunotherapy for cervical cancer

Cervical cancer still represents a major public health problem, being the fourth most common cancer in incidence and mortality in women worldwide. These figures are unacceptable since cervical cancer, an human papillomavirus-related malignancy, is a largely preventable disease by means of well-established screening and vaccination programs. Patients with recurrent, persistent, or metastatic disease unsuitable for curative therapeutic approaches represent a dismal prognosis population. Until recently, these patients were only candidates for cisplatin-based chemotherapy plus bevacizumab. However, the introduction of immune checkpoint inhibitors has revolutionized the treatment landscape of this disease achieving historical overall survival improvements in both the post-platinum and frontline settings. Interestingly, the clinical development of immunotherapy in cervical cancer is currently advancing to earlier stages of the disease, as the locally advanced setting, whose standard of care has not changed in the last decades with still modest outcomes. As more innovative immunotherapy approaches are in clinical early development in advanced cervical cancer, promising efficacy data are emerging that may shape the future of this disease. This review summarizes the main treatment advances carried out in the field of immunotherapy throughout the past years.

Perspectives on the clinical development of immunotherapy in prostate cancer.

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. Sipuleucel-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. Reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomarkers, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.

Experience with an allergen challenge chamber for clinical trials in allergic rhinitis

SummaryAllergic rhinitis has the greatest prevalence of any respiratory disease and affects about 20% of the population in North America and Europe. There is an increasing need for allergen challenge systems to test anti‐allergic drugs under well‐controlled conditions. The allergen challenge chamber (ACC) is a room that enables reproducible challenges with controlled levels of inhalant allergens, temperature and humidity for several hours. ACCs have been used in Europe, North America and Japan to evaluate symptomatic and anti‐inflammatory medications for the treatment of allergic rhinitis. This review summarizes the experience with a typical ACC in Germany, the Fraunhofer Challenge Chamber, and describes the stability and reproducibility of the allergen exposure in the chamber. It further provides data for the specificity and reproducibility of clinical read‐out parameters, such as nasal symptom scores, nasal flow rates and nasal secretions, as well as of nasal biomarkers obtained in different validation studies. Typical study designs for testing the acute and prophylactic treatment effects of anti‐allergic substances are discussed. Regulatory authorities, such as the FDA and EMA, recommend the use of ACCs in drug development to evaluate the optimal dose and onset of action during early clinical development. In combination with natural‐exposure Phase III studies, they provide supportive evidence of superiority over placebo as an additional pharmacodynamic assessment tool. In particular, ACC studies may be of additional value in the clinical development of immunotherapy, because the variability of natural allergen exposure hampers the demonstration of efficacy in clinical trials.

Molecular Mechanisms of Paraptosis Induction: Implications for a Non-Genetically Modified Tumor Vaccine

Paraptosis is the programmed cell death pathway that leads to cellular necrosis. Previously, rodent and human monocytes/macrophages killed glioma cells bearing the membrane macrophage colony stimulating factor (mM-CSF) through paraptosis, but the molecular mechanism of this killing process was never identified. We have demonstrated that paraptosis of rat T9 glioma cells can be initiated through a large potassium channel (BK)-dependent process initiated by reactive oxygen species. Macrophage mediated cytotoxicity upon the mM-CSF expressing T9-C2 cells was not prevented by the addition of the caspase inhibitor, zVAD-fmk. By a combination of fluorescent confocal and electron microscopy, flow cytometry, electrophysiology, pharmacology, and genetic knock-down approaches, we demonstrated that these ion channels control cellular swelling and vacuolization of rat T9 glioma cells. Cell lysis is preceded by a depletion of intracellular ATP. Six-hour exposure to BK channel activation caused T9 cells to over express heat shock proteins (Hsp 60, 70, 90 and gp96). This same treatment forced HMGB1 translocation from the nuclear region to the periphery. These last molecules are “danger signals” that can stimulate immune responses. Similar inductions of mitochondrial swelling and increased Hsp70 and 90 expressions by BK channel activation were observed with the non-immunogenic F98 glioma cells. Rats injected with T9 cells which were killed by prolonged BK channel activation developed immunity against the T9 cells, while the injection of x-irradiated apoptotic T9 cells failed to produce the vaccinating effect. These results are the first to show that glioma cellular death induced by prolonged BK channel activation improves tumor immunogenicity; this treatment reproduces the vaccinating effects of mM-CSF transduced cells. Elucidation of strategies as described in this study may prove quite valuable in the development of clinical immunotherapy against cancer.

New developments in immunotherapy for non-Hodgkin’s lymphoma

The clinical development of immunotherapy with rituximab (chimeric anti-CD20 monoclonal antibody) has markedly affected the treatment approach for patients with B-cell non-Hodgkin's lymphoma (NHL). Rituximab was initially evaluated in relapsed indolent lymphoma and has substantial activity in this setting both alone and in combination with chemotherapy. Ongoing efforts in indolent NHL are seeking to optimize the dose and schedule of rituximab through "maintenance" strategies exploring chemotherapy-rituximab combinations and the use of other biologic agents or antibodies that may enhance activity when employed together with rituximab. Other studies in indolent NHL suggest that radiolabeled anti-CD20 antibodies (such as I-131 tositumomab and Y-90 ibritumomab tiuxetan) may be useful in relapsed and refractory disease and have potential utility as part of initial treatment as well. In diffuse large B-cell lymphoma, the addition of rituximab to CHOP chemotherapy can improve survival, though benefits are more limited in mantle cell lymphoma. Further studies of unlabeled and radiolabeled immunotherapies are ongoing in order to optimize their use for maximal clinical benefit.

Selective MHC expression in tumours modulates adaptive and innate antitumour responses.

Progress towards developing vaccines that can stimulate an immune response against growing tumours has involved the identification of the protein antigens associated with a given tumour type. Epitope mapping of tumour antigens for HLA class I- and class II-restricted binding motifs followed by immunization with these peptides has induced protective immunity in murine models against cancers expressing the antigen. MHC class I molecules presenting the appropriate peptides are necessary to provide the specific signals for recognition and killing by cytotoxic T cells (CTL). The principle mechanism of tumour escape is the loss, downregulation or alteration of HLA profiles that may render the target cell resistant to CTL lysis, even if the cell expresses the appropriate tumour antigen. In human tumours HLA loss may be as high as 50%, inferring that a reduction in protein levels might offer a survival advantage to the tumour cells. Alternatively, MHC loss may render tumour cells susceptible to natural killer cell-mediated lysis because they are known to act as ligands for killer inhibitory receptors (KIRs). We review the molecular features of MHC class I and class II antigens and discuss how surface MHC expression may be regulated upon cellular transformation. In addition, selective loss of MHC molecules may alter target tumour cell susceptibility to lymphocyte killing. The development of clinical immunotherapy will need to consider not only the expression of relevant CTL target MHC proteins, but also HLA inhibitory to NK and T cells.