Safety Of Cancer Vaccines Research Articles

Enhanced in vivo anti-tumor efficacy of whole tumor lysate in combination with whole tumor cell-specific polyclonal antibody.

Despite the widespread utilization of cancer vaccines with specified antigens, the use of whole tumor cell lysates in tumor immunotherapy would be a very promising approach that can overcome several significant obstacles in vaccine production. Whole tumor cells provide a broad source of tumor-associated antigens and can activate cytotoxic T lymphocytes and CD4+ T helper cells concurrently. On the other hand, as an effective immunotherapy strategy, recent investigations have shown that the multi-targeting of tumor cells with polyclonal antibodies, which are also more effective than monoclonal antibodies at mediating effector functions for target elimination, might minimize the escape variants. We prepared polyclonal antibodies by immunizing rabbits with the highly invasive 4T1 breast cancer cell line. In vitro investigation indicated that the immunized rabbit serum inhibited cell proliferation and induced apoptosis in target tumor cells. Moreover, in vivo analysis showed enhanced anti-tumor efficacy of whole tumor cell lysate in combination with tumor cell-immunized serum. This combination therapy proved beneficial in significant inhibition of the tumor growth and the established tumor was entirely eradicated in treated mice. Serial intravenous injections of tumor cell immunized rabbit serum significantly inhibited tumor cell proliferation and induced apoptosis in vitro and in vivo in combination with whole tumor lysate. This platform could be a promising method for developing clinical-grade vaccines and open up the possibility of addressing the effectiveness and safety of cancer vaccines.

Advanced therapies push regulatory boundaries: Novel therapeutic approaches require more regulatory flexibility and transparency.

The regulation of new medical applications has always been lagging behind the science that enabled these therapies in the first place, but emerging therapeutic approaches are pushing the boundaries harder than ever. Although fundamental principles around safety, efficacy and quality are cast in stone, new interpretations and greater flexibility are required for the clinical use of advanced medicines and treatments without introducing unacceptable risks. There are also ethical considerations that, although not new, are amplified by the potential of emerging therapies to address previously untreatable conditions. All major regulatory bodies, such as the US Food and Drug Administration (FDA) and the European Medical Agency (EMA), have for some years been aware of the challenges posed in particular by Advanced Therapy Medicinal Products (ATMPs). These roughly include three categories: gene therapy medicinal products (GTMPs), somatic cell therapy medicinal products (SCTMPs) and tissue‐engineered products (TEPs), many of which have emerged from the “omics” revolution and stem cell research. > All major regulatory bodies […] have for some years been aware of the challenges posed in particular by Advanced Therapy Medicinal Products ### Advanced Therapy Medicinal Products Both GTMPs and SCTMPs involve ex vivo manipulation of cells, but with a crucial difference in terms of manufacture and function. GTMPs deliver recombinant DNA to specific target cells in the body, whereas SCTMPs are whole cells or tissues genetically manipulated to change their biological characteristics or functions for preventing, diagnosing or treating disease. These cells can be autologous, coming from the patient, allogeneic from another human being or xenogeneic from animals. One recent example of GMTP is recombinant viral vaccines against cancer engineered from an immunogenic virus particle to express tumour antigens, cytokines or both [1]. SCTMPs were the first AMPs to be tested clinically in 1997 for corneal epithelial stem cell transplantation. Since then, the technique has been …

Current Algorithm for Treatment of Advanced NSCLC Patients: How to Include Active Immunotherapy?

Despite the availability of different treatments for advanced NSCLC, all of them have a palliative intention and a cure for the disease is unlikely. Thus, advanced lung cancer remains as an unmet medical need. Chemotherapy has been used as the therapy of choice for advanced NSCLC patients, but it is mainly limited by the patient’s performance status. More recently, targeted therapies have introduced more specific treatment options that show efficacy in specific niche of patients, but precisely due to their target specificity, they usually provoke early resistance. In addition to these limitations, most of the best drugs currently used for treatment of advanced NSCLC show small increases in patient survival with severe associated toxicity. Novel drugs with low toxicity that could be given chronically to control the advanced disease can make a difference. They could allow the management of advanced cancer as a chronic disease that, even when not cured, it can be controlled for long periods of time offering patients a good quality of life. Active-specific immunotherapy is an area of oncology that is rapidly expanding with encouraging results. Cancer vaccines against many potential targets have shown to increase patient survival in clinical trials at all stages NSCLC, when included as first-line, maintenance, or second-line therapy. Safety of cancer vaccines supposes a new hope for cancer therapy, and this unique characteristic makes it possible to be used in sub-sets of patients that cannot receive other approved treatments because of their high toxicity. In this paper, authors propose how active immunotherapy could be included in the current algorithm for treatment of advanced NSCLC patients.

Efficacy and safety of cancer vaccine with 4-fold gene-modified allogeneic tumor cells: Results of the phase I/II ASET study in patients with advanced renal cell carcinoma.

4636 Background: MGN1601 was tested in the first-in-man phase I-II clinical study in patients with advanced renal cell carcinoma (RCC) who failed several previous therapy lines and had no further standard therapy available. MGN1601 consists of two active pharmaceutical ingredients in fixed combination: fourfold gene-modified allogeneic tumor cells expressing IL-7, GM-CSF, CD80 and CD154 through MIDGE vectors and a TLR-9 agonist, the immunomodulator dSLIM. Methods: The ASET study is a multicentric, single-arm phase I-II clinical trial. Clinical response was evaluated using CT scans (RECIST 1.1 or immune related Response Criteria, irRC). Efficacy data were evaluated in terms of PFS and OS for the intended to treat and the treated per protocol (TPP) populations, clinical parameters and quality of life. Immune response was determined using DTH to MGN1601, LTT assay, frequency and activation of blood cells, and mRNA, chemokine and cytotoxic T cells analysis as well as tumor tissue evaluation. Results: Nine of 19 included patients completed the TPP, the others discontinued the study earlier due to PD. Median PFS in the TPP group was 12 wks (3 months) and OS (not reached yet) 46 wks (11 months). Three patients achieved disease control (1 PR, 2 SD) after 12 wks. Two patients are continuing treatment in the extension phase and are progression free since 37 and 46 wks, respectively. Re-evaluation of tumor response data using irRC revealed 1 additional patient with a delayed tumor response 4 wks after treatment stop. Herewith, 4 out of 9 TPP patients (45%) achieved disease control. Of 7 patients receiving targeted therapy upon stop of study treatment, 4 had substantial objective responses, providing evidence that the study drug is able to render their tumors more vulnerable to subsequent therapies. Immune analysis showed trends towards increases of T-, NKT-cell and pDC frequencies and other immune parameters in those patients with clinical responses, indicating anti-tumor immunity of study treatment. Conclusions: The therapeutic cancer vaccine MGN1601 shows promising efficacy in late stage mRCC patients. Results warrant further clinical studies with MGN1601.