Tag: immunotherapy

Categories : Cancer GastrointestinalTags :

Researchers Figure out Why Cancer Immunotherapy can Cause Colitis

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Gastrointestinal inflammation. Credit: Scientific Animations CC4.0

Researchers have identified a mechanism behind immunotherapy sometimes causing colitis. They also found a way to deliver immunotherapy’s cancer-killing impact without the unwelcome side effect. The researchers, from the University of Michigan Health Rogel Cancer Center, published their findings in Science.

“This is a good example of how understanding a mechanism helps you to develop an alternative therapy that’s more beneficial. Once we identified the mechanism causing the colitis, we could then develop ways to overcome this problem and prevent colitis while preserving the anti-tumour effect,” said senior study author Gabriel Nunez, MD, professor of pathology at Michigan Medicine.

Immunotherapy is a promising treatment for several types of cancer. But immune checkpoint inhibitors can also cause severe side effects, including colitis. Colitis can cause severe gastrointestinal discomfort, causing some patients to discontinue their cancer treatment because of it.

The problem facing researchers was that while patients were developing colitis, the laboratory mice were not, preventing them from studying the cause of this side effect.

To get past this, the Rogel team, led by first author Bernard C. Lo, PhD, created a new mouse model, injecting microbiota from wild-caught mice into the traditional mouse model.

In this model, the mice did develop colitis after administration of antibodies used for tumour immunotherapy. Now, researchers could trace back the mechanism to see what was causing this reaction.

In fact, colitis developed because of the composition of the gut microbiota, which caused immune T cells to be hyper-activated while regulatory T cells that put the brakes on T cell activation were deleted in the gut. This was happening within a specific domain of the immune checkpoint antibodies.

Researchers then removed that domain, which they found still resulted in a strong anti-tumour response but without inducing colitis.

“Previously, there were some data that suggested the presence of certain bacteria correlated with response to therapy. But it was not proven that microbiota were critical to develop colitis. This work for the first time shows that microbiota are essential to develop colitis from immune checkpoint inhibition,” Nunez said.

To follow up what they saw in mice, researchers reanalysed previously reported data from studies of human cells from patients treated with immune checkpoint antibodies, which reinforced the role of regulatory T cells in inducing colitis.

The Rogel team plans additional studies to further understand the mechanisms causing colitis and seeks clinical partners to move this knowledge to a clinical trial.

Source: Michigan Medicine – University of Michigan

Categories : CancerTags :

New Combination Salvages Immunotherapy Drug for Breast Cancer

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Immunotherapy in combination with chemotherapy has become an important therapeutic treatment option in some patients with metastatic breast cancer. Which patients will benefit the most, however, remains unclear; current biomarkers such as PD-L1 that are used to predict response are mediocre at best. Vanderbilt researchers led a clinical trial combining atezolizumab, an immunotherapy, in combination with chemotherapy in patients with metastatic triple-negative breast cancer to both evaluate the efficacy of the treatment combination and to understand biomarkers of response to immunotherapy.

Atezolizumab became the first approved immunotherapy for breast cancer when the Food and Drug Administration granted it accelerated approval in 2019, but two years later, its maker voluntarily withdrew the indication after additional data from a follow-up clinical trial failed to corroborate its efficacy. Atezolizumab had been approved for metastatic PD-L1-positive triple-negative breast cancer in combination with the chemotherapy nab-paclitaxel. Results from Vanderbilt’s clinical trial, published in JAMA Oncology, indicate that this immunotherapy does have a clinically meaningful benefit with a different chemotherapy partner and the correlative analyses provide insight to which patients will respond.

The clinical trial combined atezolizumab with carboplatin – a chemotherapy that works differently than nab-paclitaxel. The new combination significantly improved progression-free and overall survival of patients with metastatic triple-negative breast cancer. Atezolizumab with carboplatin lengthened progression-free survival from a median of 2.2 months to 4.1 months. Overall survival increased from a median of 8.6 months for the control group, who received carboplatin alone, to 12.6 months for those who received the combination therapy.

The phase 2 randomized clinical trial was conducted at six cancer centers through the Translational Breast Cancer Research Consortium and involved 106 patients of diverse ethnicities.

“Triple-negative breast cancer is difficult to treat because we don’t have a clear target, and understanding the underlying factors that affect response to a treatment is key. This study is so important because we were able to collect biopsies in all of the participants and really understand factors that affect response,” said Vandana Abramson, MD, the Donna S. Hall Professor in Cancer Research and co-leader of the Breast Cancer Research Program at Vanderbilt-Ingram Cancer Center.

The researchers hypothesised that atezolizumab would have superior efficacy to carboplatin because the chemotherapy is a platinum agent, which causes structural DNA changes and generates neoantigens that may stimulate an immune response. Nab-paclitaxel chemotherapy works differently: it is a microtubule-stabilising agent that stops cancer cell division.

“The tremendous knowledge gained from our multidisciplinary analyses of the patients and their tumours will continue to be important for clinical decision-making. After our first description of the triple-negative breast cancer subtypes over 10 years ago, more recently, we refined the subtypes further into four, which were analysed in this study: two basal-like subtypes, a mesenchymal subtype and a lumen androgen receptor-expressing subtype. When we refined the triple-negative breast cancer subtypes, we revealed an immune-modulatory descriptor or correlation.

“This JAMA Oncology study and others continue to confirm that lymphocytes, as measured by the immune-modulatory correlation, have predictive value for better relapse-free survival for triple-negative patients. Further, this study provides evidence that the luminal androgen receptor subtype is more like oestrogen receptor-positive (or ER+) disease. Prior studies investigating immunotherapy in breast cancers have shown that patients with ER+ disease have less benefit from immunotherapy, and we found that to be the case with patients with luminal androgen-positive tumours in this trial,” said Jennifer Pietenpol, PhD, the study’s corresponding author.

Interestingly, patients with higher body mass indexes and uncontrolled blood glucose levels had greater benefit from atezolizumab with carboplatin. The researchers noted that these patients may have more immune cells upon which anti-PD1/PD-L1 therapies can act. A lower risk of disease progression was also associated with high mutation burden and increased tumour-infiltrating lymphocytes.

“In this study, we observed that patients received benefit with atezolizumab even if the tumours were PD-L1 negative. We also show that, like prior clinical trials in melanoma and renal and lung cancers, tumours with high mutation burdens and the presence of immune cells within or around the tumour receive greater benefit from immunotherapy. This makes sense because each mutation has the potential to be recognised as non-self by the immune system, increasing the probability of immune cells already positioned around the tumour to recognise and target the cancer,” said Brian Lehmann, PhD, Research Associate Professor of Medicine and lead correlative scientist on the study.

“One surprising finding was the trend toward greater benefit for patients with higher body mass indexes and patients with uncontrolled blood glucose at prediabetic and diabetic levels while on the study. Both obesity and diabetes are linked to systemic inflammation, and the increased benefit may be attributed to higher adipose tissue composition in the breast and augmented by metabolic syndrome conditions such as Type 2 diabetes. Further studies are necessary to validate these findings and delineate the effects of blood glucose and obesity on immunotherapy,”

The combination therapy was generally well-tolerated, and toxic effects were consistent with previous reports for atezolizumab. The most common drug complications on the combination arm of the clinical trial were low blood platelet counts, anaemia, lymphocytopenia, nausea, fatigue and increased liver enzymes. The participants identified as 69% white, 19% African American, 10% unknown and 1% Asian.

Source: Vanderbilt University Medical Center

Categories : Cancer UrogenitalTags :

New Treatment Combination could Prevent Cystectomy in Invasive Bladder Cancer

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Photo by cottonbro studio

Mount Sinai investigators have developed a new approach for treating invasive bladder cancer without the need for surgical removal of the bladder, they report in their study published in Nature Medicine. At present, cystectomy (removal of the bladder) is currently a standard approach when cancer has invaded the muscle layer of the bladder.

In a phase 2 clinical trial that was the first of its kind, doctors found that some patients could be treated with a combination of chemotherapy and immunotherapy without the need to remove their bladder. Radical cystectomy can be curative in muscle-invasive bladder cancer, but the procedure is a life-changing operation due to the need for urinary diversion and is associated with a 90 day mortality risk of up to 6–8%.

“Treatment for muscle-invasive bladder cancer is in need of major improvements from both a quality-of-life and an effectiveness standpoint,” said Matthew Galsky, MD, Co-Director of the Center of Excellence for Bladder Cancer at The Tisch Cancer Institute, a part of the Tisch Cancer Center at Mount Sinai. “If additional research confirms our findings, this may lead to a new paradigm in the treatment of muscle-invasive bladder cancer.”

The 76 patients received four cycles of gemcitabine, cisplatin, plus nivolumab followed by clinical restaging. Approximately 43% (33 patients) achieved a complete response (no detectable cancer) when treated with this combination of chemotherapy and immunotherapy. Patients with a clinical complete response were offered the opportunity to proceed with additional immunotherapy, without surgical removal of the bladder. Among patients opting to proceed without surgical removal of the bladder, about 70% had no evidence of recurrent cancer after two years.

The most common adverse events were fatigue, anaemia, neutropenia and nausea. Somatic alterations in pre-specified genes or increased tumour mutational burden did not improve the positive predictive value of complete response.

Based on the results of this trial, two follow-up studies were launched to build on this approach; one is ongoing, and another will open in the next six months.

Source: The Mount Sinai Hospital / Mount Sinai School of Medicine

Categories : Cancer PaediatricsTags :

Neuroblastomas: ‘New’ Immune System Responds Better to Therapy

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Credit: National Cancer Institute

Cancer researchers have shown that immunotherapy after stem cell transplantation effectively combats neuroblastomas in children. Crucially, stem cells from a parent provide children with a new immune system that responds much better to immunotherapies. These results of an early clinical trial were published in the Journal of Clinical Oncology.

Tumours of the nervous system, neuroblastomas are associated with an unfavourable prognosis if the tumour is classified as a high-risk type. and particularly poor for patients in the relapsed stage. In this study by scientists at St. Anna Children’s Cancer Research Institute and the Eberhard Karls University of Tübingen, immunotherapy following stem cell transplantation is now associated with long-term survival in a substantial proportion of the patients. Compared to an earlier study the survival rate was increased.

“After the transplantation of stem cells from a parent, the patients are equipped with a new immune system. This enables a better immune response to the subsequent immunotherapy and clearly improves the outcome,” explains Prof Ruth Ladenstein, MD, co-first author.

Five-year survival exceeds 50%

“After a median follow-up of about eight years, we see that more than half of the study patients live five years or longer with their disease,” Prof Ladenstein reports (5-year overall survival: 53%). In comparison, the 5-year overall survival in an earlier study, in which stem cell transplantation was not followed by immunotherapy, was only 23%. Those patients who showed a complete or partial response to prior treatment had significantly better survival.

“In summary, immunotherapy with dinutuximab beta following transplantation of stem cells from matched family donors resulted in remarkable outcomes when patients had at least a partial response to prior treatment,” says Prof Ladenstein. “In our study, there were no unexpected side effects and the frequency of graft-versus-host-disease was low.”

Restoring natural killer cell potency

Dinutuximab beta is a monoclonal antibody that binds to a molecule, GD2, on the surface of tumour cells, marking them for destruction by natural killer cells. But prior chemotherapies may impair natural killer cells. “Therefore, a transplantation of intact natural killer cells from matched family donors seems reasonable before immunotherapy is administered. The transplanted, new natural killer cells are now able to target the tumour cells more efficiently – by means of an antibody-dependent reaction,” explains Prof Ladenstein.

According to the authors, further studies are needed to determine the individual components of the therapeutic approaches. Recently, conventional chemotherapy has also been combined with immunotherapy early in the treatment strategy, resulting in similarly improved response rates. The hope is that a renewed immune system through a healthy parent in combination with the described transplantation procedure could further increase survival rates: “Our approach could thus result in stronger and longer lasting tumour control. A randomised study would be necessary to scientifically substantiate the additional potential benefit of a new immune system in the context of relapse therapy,” Prof Ladenstein adds.

Source: St. Anna Children’s Cancer Research Institute

Categories : Cancer NeurologyTags :

In A First, Immunotherapy for Glioblastoma Successfully Tested in Mice

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Photo by Kanashi ZD on Unsplash

Immunotherapy has dramatically improved survival against many cancers but efforts to use it against glioblastomas have to date proven fruitless. Now, Salk scientists have found the immunotherapy treatment anti-CTLA-4 leads to considerably greater survival of mice with glioblastoma. Furthermore, they discovered that this therapy was dependent on immune cells called CD4+ T cells infiltrating the brain and triggering the tumour-destructive activities of other immune cells called microglia, which permanently reside in the brain.

The findings, published in the journal Immunity, show the benefit of harnessing the body’s own immune cells to fight brain cancer and could lead to more effective immunotherapies for treating brain cancer in humans.

Glioblastoma, the most common and deadly form of brain cancer, grows rapidly to invade and destroy healthy brain tissue. The tumour sends out cancerous tendrils into the brain that make surgical tumour removal extremely difficult or impossible.

“There are currently no effective treatments for glioblastoma – a diagnosis today is basically a death sentence,” says Professor Susan Kaech, senior author and director of the NOMIS Center for Immunobiology and Microbial Pathogenesis. “We’re extremely excited to find an immunotherapy regimen that uses the mouse’s own immune cells to fight the brain cancer and leads to considerable shrinkage, and in some cases elimination, of the tumour.”

For some tumours, immunotherapy can be used, in which the body’s own immune cells to seek and destroy cancer cells, leading to strong, lasting anti-cancer responses for many patients. Kaech sought new ways of harnessing the immune system to develop more safe and durable treatments for brain cancer.

Her team found three cancer-fighting tools that have been somewhat overlooked in brain cancer research that may cooperate and effectively attack glioblastoma: an immunotherapy drug called anti-CTLA-4 and specialized immune cells called CD4+ T cells and microglia.

Anti-CTLA-4 immunotherapy works by blocking cells from making the CTLA-4 protein, which, if not blocked, inhibits T cell activity. It was the first immunotherapy drug designed to stimulate our immune system to fight cancer, but it was quickly followed by another, anti-PD-1, that was less toxic and became more widely used. Whether anti-CTLA-4 is an effective treatment for glioblastoma remains unknown since anti-PD-1 took precedence in clinical trials. Unfortunately, anti-PD-1 was found to be ineffective in multiple clinical trials for glioblastoma – a failure that inspired Kaech to see whether anti-CTLA-4 would be any different.

As for the specialized immune cells, CD4+ T cells are often overlooked in cancer research in favour of a similar immune cell, the CD8+ T cell, because CD8+ T cells are known to directly kill cancer cells. Microglia live in the brain full time, where they patrol for invaders and respond to damage – whether they play any role in tumour death was not clear. When treated with anti-CLA-4, mice with glioblastoma had longer lifespans than those receiving anti-PD-1.

Upon investigation, they found that after anti-CTLA-4 treatment, CD4+ T cells secreted a protein called interferon gamma that caused the tumour to throw up “stress flags” while simultaneously alerting microglia to start eating up those stressed tumour cells. As they gobbled up the tumour cells, the microglia would present scraps of tumour on their surface to keep the CD4+ T cells attentive and producing more interferon gamma, creating a cycle that lasts until the tumour is destroyed.

“Our study demonstrates the promise of anti-CTLA-4 and outlines a novel process where CD4+ T cells and other brain-resident immune cells team up to kill cancerous cells,” says co-first author Dan Chen, a postdoctoral researcher in Kaech’s lab.

To understand the role of microglia in this cycle, the researchers collaborated with co-author and Salk Professor Greg Lemke. For decades, Lemke has investigated critical molecules, called TAM receptors, used by microglia to send and receive crucial messages. The researchers found that TAM receptors told microglia to gobble up cancer cells in this novel cycle.

“We were stunned by this novel codependency between microglia and CD4+ T cells,” says co-first author Siva Karthik Varanasi, a postdoctoral researcher in Kaech’s lab. “We are already excited about so many new biological questions and therapeutic solutions that could radically change treatment for deadly cancers like glioblastoma.”

Connecting the pieces of this cancer-killing puzzle brings researchers closer than ever to understanding and treating glioblastoma.

“We can now reimagine glioblastoma treatment by trying to turn the local microglia that surround brain tumours into tumour killers,” says Kaech. “Developing a partnership between CD4+ T cells and microglia is creating a new type of productive immune response that we have not previously known about.”

Next, the researchers will examine whether this cancer-killing cell cycle is present in human glioblastoma cases. Additionally, they aim to look at other animal models with differing glioblastoma subtypes, expanding their understanding of the disease and optimal treatments.

Source: Salk Institute

Categories : Ageing CancerTags :

Losing the Y Chromosome to Age Drives Bladder Cancers but Improves Immunotherapy

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Chromosomes. Credit: NIH

As men age, some of their cells lose their Y chromosome and this loss hampers the body’s ability to fight cancer, according to new research from Cedars-Sinai Cancer. The study, published in Nature, found that loss of the Y chromosome helps cancer cells evade the immune system, resulting in aggressive bladder cancer. Somehow, this also renders the disease more responsive to immune checkpoint inhibitors.

Based on their research, investigators are developing a test for loss of the Y chromosome in tumours with the goal of helping clinicians tailor immune checkpoint inhibitor treatment for male patients with bladder cancer.

“This study for the first time makes a connection that has never been made before between loss of the Y chromosome and the immune system’s response to cancer,” said corresponding author Dan Theodorescu, MD, PhD, who initiated the research. “We discovered that loss of the Y chromosome allows bladder cancer cells to elude the immune system and grow very aggressively.”

Lead collaborators on the study also included Johanna Schafer, a postdoctoral fellow, and Zihai Li, MD, PhD, medical oncologist and immunologist, both at The Ohio State University Comprehensive Cancer Center-James Cancer Hospital and Solove Research Institute.

In men, loss of the Y chromosome has been observed in several cancer types, including 10%–40% of bladder cancers. Loss of the Y chromosome also has been associated with heart disease and Alzheimer’s disease.

The Y chromosome contains the blueprints for certain genes. Based on the way these genes are expressed in normal cells in the bladder lining, investigators developed a scoring system to measure loss of the Y chromosome in cancers.  

The investigators then reviewed data on two groups of men. One group had muscle invasive bladder cancer and had their bladders removed, but were not treated with an immune checkpoint inhibitor. The other group participated in a clinical trial and were treated with an immune checkpoint inhibitor. They found that patients with loss of the Y chromosome had poorer prognosis in the first group and much better overall survival rates in the latter.

To determine why this happens, investigators next compared growth rates of bladder cancer cells from laboratory mice.

Cancer cells were grown in vitro and not exposed to immune cells. The researchers also grew the diseased cells in mice that were missing T-cells. In both cases, tumours with and without the Y chromosome grew at the same rate.

In mice with intact immune systems, tumours lacking the Y chromosome grew at a much faster rate than did tumours with the intact Y chromosome.

“The fact that we only see a difference in growth rate when the immune system is in play is the key to the ‘loss-of-Y’ effect in bladder cancer,” Theodorescu said. “These results imply that when cells lose the Y chromosome, they exhaust T-cells. And without T-cells to fight the cancer, the tumor grows aggressively.”

Based on their results derived from human patients and laboratory mice, Theodorescu and his team also concluded that tumours missing the Y chromosome, while more aggressive, were also more vulnerable and responsive to immune checkpoint inhibitors. This therapy, one of the two mainstay bladder cancer treatments available to patients today, reverses T-cell exhaustion and allows the body’s immune system to fight the cancer.

“Fortunately, this aggressive cancer has an Achilles’ heel, in that it is more sensitive than cancers with an intact Y chromosome to immune checkpoint inhibitors,” said co-first author Hany Abdel-Hafiz, PhD, associate professor at Cedars-Sinai Cancer.

Preliminary data not yet published shows that loss of the Y chromosome also renders prostate cancers more aggressive, Theodorescu said.

“Our investigators postulate that loss of the Y chromosome is an adaptive strategy that tumour cells have developed to evade the immune system and survive in multiple organs,” said Shlomo Melmed, MB, ChB, dean of the Medical Faculty at Cedars-Sinai. “This exciting advance adds to our basic understanding of cancer biology and could have far-reaching implications for cancer treatment going forward.”

Further work is needed to help investigators understand the genetic connection between loss of the Y chromosome and T-cell exhaustion.

“If we could understand those mechanics, we could prevent T-cell exhaustion,” Theodorescu said. “T-cell exhaustion can be partially reversed with checkpoint inhibitors, but if we could stop it from happening in the first place, there is much potential to improve outcomes for patients.”

While women do not have a Y chromosome, Theodorescu said these findings could have implications for them as well. The Y chromosome contains a set of related genes, called paralogue genes, on the X chromosome, and these might play a role in both women and in men. Additional research is needed to determine what that role might be.

“Awareness of the significance of Y chromosome loss will stimulate discussions about the importance of considering sex as a variable in all scientific research in human biology,” Theodorescu said. “The fundamental new knowledge we provide here may explain why certain cancers are worse in either men or women, and how best to treat them. It also illustrates that the Y chromosome does more than determine human biologic sex.”

Source: Cedars-Sinai Medical Center

Categories : Cancer Cardiovascular DiseaseTags :

Some Antihypertensives might Boost the Effectiveness of Cancer Immunotherapy

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Photo by CDC on Unsplash

A study reported in the latest issue of Nature has shown that some molecules previously used to treat hypertension might also help the immune system to better target cancer cells. The researchers believe that these findings could eventually be applied to significantly improve the effectiveness and applicability of cancer immunotherapy.

“Immunotherapy today can effectively fight only 30% to 40% of cancers,” said Benoît Van den Eynde, at the Ludwig Institute for Cancer Research, co-director of the de Duve Institute and professor of Tumour Immunology at the University of Oxford. “Many cancers are resistant, largely because their T lymphocytes are not reactive enough. We discovered that drugs once used to treat hypertension could have a very interesting effect in combating these forms of immunotherapy-resistant cancers.”

T lymphocytes are active components in the immune system, recognising and destroying cells that appear foreign. Cancer cells, however, are not foreign and are therefore often not recognised and attacked by T lymphocytes. But about thirty years ago, Thierry Boon and his colleagues at the former Brussels Branch of the Ludwig Institute for Cancer Research at the de Duve Institute discovered specific markers on the surface of cancer cells – tumour antigens – that can be recognised by T cells that then destroy the cancerous cells.

This work paved the way for cancer immunotherapy, a treatment approach that helps T cells destroy cancerous cells. Thanks to T cells’ specificity and memory of tumour antigens, immunotherapy makes it possible to treat advanced cancers with some success. It is now used worldwide. However, such therapies are not equally effective in all patients or against all types of cancer.

In the current study, a team led by Jingjing Zhu in Van den Eynde’s laboratory shows that anti-hypertensive drug-molecules known as α2-adrenergic receptor (α2AR) agonists also influence the behaviour of macrophages. While doing that job, macrophages also alert T cells of any abnormalities they encounter, presenting suspicious antigens to the cells to trigger a possible immune response.

Zhu, Van den Eynde and colleagues discovered that alongside their known hypotensive and anaesthetic effects, α2AR agonists can also stimulate macrophages in their role as sentinels, making T cells more reactive and more effective at rejecting cancer cells. The effect extended, most notably, to cancer models that are resistant to standard immunotherapy. This suggests the new approach could boost the efficacy of clinical immunotherapy, even for the many types of cancer that are largely unresponsive to such interventions.

These findings also present a rationale for the development of new molecules that might be used in combination with immunotherapy to improve its efficacy.

“One could imagine using existing blood pressure-lowering drugs,” said Van den Eynde. “But that would be quite risky, owing to the undesired effects and the toxicity of these drugs at the necessary doses. Another approach would be to develop new molecules that would act in the same way on macrophages but would not have the unwanted toxic effects. We have already made significant progress in this direction.”

Source: Ludwig Cancer Research

Categories : CancerTags :

Osteoporosis Drug Zolendronate Could also Help Fight Breast Cancer

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Killer T cells about to destroy a cancer cell.

Triple-negative breast cancer (TNBC) is the most aggressive and deadly form of breast cancer with limited treatment options and a high probability of recurrence. Researchers from the University of Frieburg discovered that coordinated differentiation and changes in the metabolism of breast cancer stem cells make them invisible for the immune system. Counteracting the metabolic change with the drug zolendronate could make immunotherapy using gamma delta T cells more efficient against TNBC. The research team was led by Prof Dr Susana Minguet and published in Cancer Immunology Research.

TNBC cells hide from gamma delta T cells

Gamma delta T cells recognise and kill cells that produce stress-induced molecules and phosphoantigens, a common characteristic of cancer cells. Because gamma delta T cells work differently to other types of T cells, they are being investigated as an alternative to existing immunotherapies. In the current study, the researchers tested the effect of gamma delta T cells on TNBC using isolated cancer cells and a recently developed mouse model that closely replicates the tumour properties found in human patients.

While the gamma delta T cells worked well against isolated breast cancer stem cells from patients, they had a much weaker effect in the mouse model. This was due to adaptations of the cancer cells that let them stay unnoticed by the immune system, the researchers found. These adaptations included the downregulation of the so-called mevalonate pathway: a metabolic pathway that leads to the production of phosphoantigens – one of the classes of molecules that gamma T cells recognise. This escape mechanism likely also happens in patients with TNBC: analysis of public patient databases showed that reduced expression of key molecules of the mevalonate pathway correlate with a worse prognosis.

The immune evasion of TNBC cells is reversible

This newly discovered escape mechanism can be counteracted by the drug zolendronate, which is FDA-approved for the treatment of osteoporosis and bone metastasis. When the researchers treated the escapist cells with zolendronate, the gamma T cells became a lot more efficient in clearing the cancer. “Our findings explain why current clinical trials using gamma delta T cells are not resulting in the expected success,” Minguet summarises. “We found a possible pharmacological-based approach to revert immune escape, which paves the way for novel combinatorial immunotherapies for triple negative breast cancer.”

Source: University of Freiburg

Categories : Cancer Immune SystemTags :

Vitamin D may be Necessary for Effective Immunotherapy in Skin Cancer

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

Vitamin D has many effects on the body, including regulation of the immune system. New research indicates that for patients with advanced skin cancer, it may be important to maintain normal vitamin D levels when receiving immunotherapy in the form of immune checkpoint inhibitors. The findings are published in CANCER.

To see whether levels of vitamin D might impact the effectiveness of immune checkpoint inhibitors, investigators analysed the blood of 200 patients with advanced melanoma both before and every 12 weeks during immunotherapy treatment.

A favourable response rate to immune checkpoint inhibitors was observed in 56.0% of patients in the group with normal baseline vitamin D levels or normal levels obtained with vitamin D supplementation, compared with 36.2% in the group with low vitamin D levels without supplementation. Progression‐free survival in these groups was 11.25 and 5.75 months, respectively.

“Of course, vitamin D is not itself an anti-cancer drug, but its normal serum level is needed for the proper functioning of the immune system, including the response that anti-cancer drugs like immune checkpoint inhibitors affect,” said lead author Łukasz Galus, MD, of Poznan University of Medical Sciences, in Poland. “In our opinion, after appropriately randomised confirmation of our results, the assessment of vitamin D levels and its supplementation could be considered in the management of melanoma.”

Source: Wiley

Categories : Cancer Immune SystemTags :

Towards Treating Dangerous Immunotherapy Side Effects

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Photo by Tima Miroshnichenko on Pexels

While immunotherapy has been shown to greatly improve survival rates for certain types of cancer, in some cases, it can lead to a dangerous over-activation of the immune system. In a recent review published in Journal for ImmunoTherapy of Cancer, potential therapies have been identified, which might make it possible to continue with immunotherapy even when facing severe side effects.

The rare immunotherapy side effect of over-activation was only clinically recognised during regular clinical use rather than in clinical trials or animal experiments. To better understand this over-activation, Lisa Liu, Marco Gerling, and colleagues analysed data from all published international reports on this issue after cancer immunotherapy. Their findings indicate that potentially life-threatening inflammation may occur more frequently than previously thought, and might be treatable with existing drugs such as steroids or anti-inflammatory therapies commonly used for rheumatoid arthritis.

“It will be exciting to follow up on the main findings of our systematic review, says Marco Gerling at the Department of Biosciences and Nutrition, Karolinska Institutet and lead author.

“We believe that inhibition of a specific inflammatory molecule, interleukin-6, could allow patients to continue immunotherapy despite strong, systemic activation of the immune system”, he continues. “But we need more data to support the regular use of interleukin-6 inhibitors. We also want to thank Narcisa Hannerz and Sabine Gillsund from Karolinska University Library for their invaluable help with finding articles for this review.“

Source: Karolinska Institutet