Addition of SRL 172 to standard chemotherapy in small cell lung cancer (SCLC) improves symptom control

Mycobacteria-Based Vaccines as Immunotherapy for Non-urological Cancers

The arsenal against different types of cancers has increased impressively in the last decade. The detailed knowledge of the tumor microenvironment enables it to be manipulated in order to help the immune system fight against tumor cells by using specific checkpoint inhibitors, cell-based treatments, targeted antibodies, and immune stimulants. In fact, it is widely known that the first immunotherapeutic tools as immune stimulants for cancer treatment were bacteria and still are; specifically, the use of Mycobacterium bovis bacillus Calmette-Guérin (BCG) continues to be the treatment of choice for preventing cancer recurrence and progression in non-invasive bladder cancer. BCG and also other mycobacteria or their components are currently under study for the immunotherapeutic treatment of different malignancies. This review focuses on the preclinical and clinical assays using mycobacteria to treat non-urological cancers, providing a wide knowledge of the beneficial applications of these microorganisms to manipulate the tumor microenvironment aiming at tumor clearance.

Immunotherapy treatments for small-cell lung cancer: past, present and future

Small-cell lung cancer remains a considerable cause of morbidity and mortality. To this day, first-line therapy continues to be a platinum agent with etoposide, combined with radiation therapy in cases of limited stage disease. Numerous, largely unsuccessful, attempts at controlling the disease have included different chemotherapy strategies, the utilization of antiangiogenic agents, tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors and other treatment modalities. Immunotherapy, including vaccines, immune response modifiers, inhibitors of check point blockades and immunologic-targeted toxins may well be the future of treatment, not only to enhance the proven chemotherapy effects, but to improve the control of minimal residual disease and the response with salvage chemotherapy. This article reviews the current advances in immunotherapeutic strategies against small-cell lung cancer.

Immunotherapy of cancer in 2012

The immunotherapy of cancer has made significant strides in the past few years due to improved understanding of the underlying principles of tumor biology and immunology. These principles have been critical in the development of immunotherapy in the laboratory and in the implementation of immunotherapy in the clinic. This improved understanding of immunotherapy, enhanced by increased insights into the mechanism of tumor immune response and its evasion by tumors, now permits manipulation of this interaction and elucidates the therapeutic role of immunity in cancer. Also important, this improved understanding of immunotherapy and the mechanisms underlying immunity in cancer has fueled an expanding array of new therapeutic agents for a variety of cancers. Pegylated interferon-α2b as an adjuvant therapy and ipilimumab as therapy for advanced disease, both of which were approved by the United States Food and Drug Administration for melanoma in March 2011, are 2 prime examples of how an increased understanding of the principles of tumor biology and immunology have been translated successfully from the laboratory to the clinical setting. Principles that guide the development and application of immunotherapy include antibodies, cytokines, vaccines, and cellular therapies. The identification and further elucidation of the role of immunotherapy in different tumor types, and the development of strategies for combining immunotherapy with cytotoxic and molecularly targeted agents for future multimodal therapy for cancer will enable even greater progress and ultimately lead to improved outcomes for patients receiving cancer immunotherapy.

Potential for immunotherapy with heat-killed Mycobacterium vaccae in respiratory medicine

Immunotherapy with Mycobacterium vaccae has been shown to be beneficial as part of the treatment for a wide range of diseases. In the respiratory system, the late airway response in bronchial asthma is modified by a single dose and bronchial aspects of hayfever are reduced allowing a major reduction in the use of bronchial dilators. In studies of advanced adenocarcinoma of the lung survival is increased by an average of 4 months when up to five doses of M. vaccae are added to the course of chemotherapy. The quality of life of cancer patients receiving immunotherapy with M. vaccae is improved, even if survival is not increased. It is suggested that the mechanism of action of immunotherapy with heat-killed, borate-buffered M. vaccae is likely to be very similar in all these diseases for which human pulmonary tuberculosis provides a model. In this study, additional immunological data are reported from material stored from an earlier study of immunotherapy for pulmonary tuberculosis to help complete the information on the way that treatment with three monthly injections of heat-killed, borate-buffered M. vaccae (SRL172) may act.

Current developments with peptide-based human tumor vaccines

PURPOSE OF REVIEW

Cancer immunology became scientifically credible only some 20 years ago with the demonstration of the existence of human tumor antigens. In this short time span, outcomes of cancer vaccine trials have raised hopes and also surfaced disappointments. This review focuses on the prospects of peptide-based vaccines in cancer immunotherapy.

RECENT FINDINGS

Accurate descriptions of the natural immune responses to cancer allow for a more precise targeting of such tumors by boosting preexisting antitumor immune responses in patients. The development of synthetic long-peptide vaccines avoids many of the pitfalls of previous vaccination trials through the presence of multiple epitopes that may elicit memory antitumor immune responses. Furthermore, the combination of standard therapy with newly developed immunomodulating agents, such as antibodies blocking cytotoxic T lymphocyte-associated antigen-4 or programmed death receptor-1, and more efficient immune adjuvants has shown promising results.

SUMMARY

Immunotherapy is becoming an effective means of targeting human cancers, and the application of such approaches in combination with current standard schemes of treatment can lead to a significant benefit in survival and quality of life for cancer patients.

Immunotherapy for malignant melanoma--tracing Ariadne's thread through the labyrinth

A working group (FEBIM) within the European Organisation for Research and Treatment of Cancer undertook extensive studies on the possible association of infectious diseases and the risk of malignant melanoma. These studies provided evidence that several infectious diseases and also some vaccines including the anti-tuberculosis vaccine, BCG, derived from Mycobacterium bovis, confer a significant level of protection against this form of cancer. In recent years, the importance of immunoregulatory networks in the establishment of tolerance to tumour antigens and the key role of the innate immune system in the development of such networks have been recognised. The molecular patterns of micro-organisms activate pattern recognition receptors on antigen presenting cells and determine the qualitative nature of the ensuing immune response. Bacteria in the actinomycetales family, notably members of the genus Mycobacterium, exhibit particularly powerful adjuvant activity and profoundly affect underlying patterns of immune reactivity. In particular, there is growing evidence that a heat-killed preparation of a strain of Mycobacterium vaccae is able to down-regulate patterns of immune reactivity that favour the tumour and to induce those that lead to anti-cancer immune responses. The results of preliminary clinical observations with melanoma patients, and published studies on other cancers, point to the need for more formal clinical trials.

An evaluation of a preparation of Mycobacterium vaccae (SRL172) as an immunotherapeutic agent in renal cancer

Two studies were carried out to evaluate heat-killed Mycobacterium vaccae SRL172 as an immunotherapeutic agent for patients with metastatic, post-nephrectomy, renal cell carcinoma. In the first study, 60 patients in France and the UK received injections of SRL172, and their survival was compared with that of historical controls who had been treated either with biological response modifiers (IL-2, IFN-alpha) or chemotherapy. In the second study, 36 patients were randomised to receive treatment with IL-2 alone or IL-2 plus SRL172. Survival and adverse events related to the treatments were assessed and compared between treatment groups. The first study showed that those treated with SRL172 alone survived equally as long as those receiving IL-2 or IFN-alpha and both treatment groups survived longer than those on chemotherapy (p<0.001), a result supported by Cox's proportional hazards regression analysis. The second study, stopped early due to drug supply issues, showed that the addition of SRL172 to IL-2 made no difference to survival compared to IL-2 alone, in the limited numbers treated. Adverse events occurring in those receiving SRL172 in the first study were mild and in the second study those receiving IL-2 alone had significantly more adverse events than those receiving SRL172 plus IL-2 (p<0.001). It is concluded that SRL172 may have activity in metastatic renal cancer and has very low toxicity, making it worthy of further study.

Cancer vaccines as a therapeutic modality: The long trek

The development of cancer vaccines has been one of the several false dawns in which initial promising Phase I and Phase II clinical data have not been followed up with conclusive Phase III trials. In this review, we describe some of the successes and failures, and review the most likely reasons for Phase III failure, such as protocol changes, which are common between Phase II and III, and poorly defined patient groups. Nevertheless, significant survival results have been reported with autologous vaccines for colorectal, renal and, more recently, prostate cancer. In addition, it is becoming evident that immunotherapy is potentially synergistic with other treatment modalities, such as chemotherapy, which can reduce T-regulatory activity that inhibits the immune response to cancer vaccines. This potential for synergy should allow cancer vaccines to become part of the standard treatment regimen for many common tumours.