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Espaço de publicação e discussão sobre oncologia. GBM IMMUNOTHERAPY ONCO-VIRUS ONCOLOGY CANCER CHEMOTHERAPY RADIOTHERAPY


Sábado, 25.07.15

Low-grade brain tumor diagnosis redefined

 

Low-grade brain tumor diagnosis redefined

 

A tumor's DNA, and not just the tumor stage and what the affected cells look like under a microscope, is key to determining if a lower-grade malignant brain tumor (glioma) may rapidly progress to glioblastoma, the most common and deadliest form of malignant brain cancer. This multicenter, national study, and its proposed changes in how some brain tumors are classified and ultimately treated, were published in the New England Journal of Medicine (2015; doi:10.1056/NEJMoa1402121).

The findings, according to researchers from the Hermelin Brain Tumor Center at Henry Ford Hospital in Detroit, MI, could result in earlier and more aggressive treatment for those tumors projected to be on the fast path. Looking at DNA changes may also open treatment options in a move toward precision medicine.

Glioma is the most common type of malignant brain tumor with 6,500 expected cases of grade 2 and grade 3, and 12,500 expected cases of grade 4 (glioblastoma) each year.

Though glioblastoma has notably poor prognosis, the lower grades have survival that is harder to predict. Some patients may progress and succumb by 6 months, while others may survive 15 years. In this study, diagnosis criteria using changes in tumor DNA was found to improve the prediction.

Glioma is very difficult to treat successfully because, rather than being a clearly defined mass, the tumor blends with healthy brain tissue and sends out tentacles of microscopic cancer cells. This makes complete neurosurgical resection impossible and leaves the chance for tumor recurrence and progression.

"This new study holds a great deal of promise for our patients because we will no longer have to wait the months or years after surgery to determine if a particular glioma will progress to a glioblastoma," said Steven N. Kalkanis, MD, co-director of the Hermelin Brain Tumor Center.

"Now genes in the tumor can be quickly analyzed to look for any changes, deletions or other mutations, allowing us the opportunity to treat gliomas that may become glioblastomas more aggressively at the start, potentially leading to longer survival."

For more than 100 years, clinicians have been diagnosing and determining treatment for gliomas based on histologic classes developed in the early 1900s. Using this method, gliomas were classified microscopically on the basis of their similarity to a specific cell of origin (astrocyte, oligodendrocyte or a mixture of these cells), often making diagnosis subjective.

But diagnosis based on the molecular make up of a tumor takes away a great deal of uncertainty and offers a more concrete diagnosis. The study analyzed 293 lower-grade gliomas (grade 2 and grade 3) from adults. The samples were integrated with patient clinical data to test for associations.

For the study, gliomas were clustered into classes based on their genetic similarity. These clusters were then compared against tumor grade, histologic class, and molecular subtype.

When the researchers grouped gliomas according to IDH gene mutation and chromosome deletion status, they found three distinct molecular classes emerge that were more consistent with IDH gene mutation and 1p/19q chromosome deletion than with histologic class.

These findings suggest that lower-grade gliomas with wild-type IDH gene mutations are likely to behave like tumors diagnosed as glioblastoma with wild-type IDH.

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por cyto às 11:54

Terça-feira, 21.07.15

Ludwig, CRI launch clinical trials to evaluate immunotherapies for treatment of GBM and solid tumors

 

Ludwig, CRI launch clinical trials to evaluate immunotherapies for treatment of GBM and solid tumors

Published on July 8, 2015 at 11:50 PM 

Ludwig Cancer Research (Ludwig) and the Cancer Research Institute (CRI) have launched clinical trials evaluating an immunotherapy for the treatment of the brain cancer glioblastoma multiforme (GBM), and a combination of immunotherapies for a variety of solid tumors.

The trials are being conducted through the CVC Clinical Trials Network in collaboration with MedImmune, the global biologics research and development arm of AstraZeneca. The CVC Clinical Trials Network -- jointly managed by Ludwig and CRI -- is a coordinated global network of basic and clinical immunologists with expertise in devising and developing immunotherapies for the treatment of cancer. The CVC Clinical Trials Network is led by Jedd Wolchok, Ludwig member and director of the Ludwig Collaborative Laboratory at Memorial Sloan Kettering Cancer Center, as well as associate director of the CRI Scientific Advisory Council.

The GBM trial is a nonrandomized, multicenter Phase 2 trial testing the effects of MedImmune's checkpoint blockade antibody durvalumab (MEDI4736) in patients with GBM, which is the most aggressive and deadly type of adult brain cancer. The study will be conducted using three cohorts of patients - newly diagnosed, recurrent patients and those with tumors which have become unresponsive to standard treatment of care.

"GBM is an inevitably lethal cancer that has so far eluded every therapy in the pharmaceutical arsenal," said Jonathan Skipper, Ludwig's executive director of technology development. "We are hopeful that adding a promising immunotherapy to the treatment regimen for this brain cancer will yield significant benefits for patients who today have a median life expectancy of roughly 15 months, even with the best treatment available."

Durvalumab is an investigational human monoclonal antibody directed against programmed cell death ligand 1 (PD-L1). Signals from PD-L1 help tumors avoid detection by the immune system. Durvalumab blocks these signals, countering the tumor's immune-evading tactics. The antibody belongs to an emerging class of immunotherapies commonly referred to as checkpoint inhibitors because they remove checks the body places on immune activation.

"Checkpoint inhibitors have deservedly stirred considerable excitement in the oncology community as their application yields notable results against a growing variety of cancers," said Adam Kolom, managing director of CRI's venture fund and Clinical Accelerator, which organizes and provides philanthropic funding and clinical resources for this and other promising immunotherapy trials. "This will be the first time the immunotherapeutic agent will be tested against this difficult-to-treat cancer, and its outcomes are eagerly anticipated by the GBM patient community."

The other trial, which Ludwig and CRI launched in 2013, is a Phase 1 nonrandomized multicenter trial evaluating the combination of durvalumab with another checkpoint blockade therapy (tremelimumab, anti-CTLA-4) for the treatment of a variety of advanced solid tumors including ovarian cancer, non-small cell lung cancer, colorectal cancer, head and neck cancer, cervical cancer and kidney cancer.

Both clinical trials, which are now under way, are part of a larger clinical research program supported by Ludwig and CRI to speed the evaluation of novel cancer immunotherapies, alone or in combination with other cancer drugs. All of the studies will include collection of genetic and immunologic data derived from clinical samples obtained from patients. Such information will provide clues to the impact of the evaluated therapies and suggest refined or new strategies for treating cancer.

Source:

Ludwig Institute for Cancer Research

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por cyto às 18:12

Sábado, 04.07.15

gene mutation linked to anaplastic oligodendroglioma

Scientists identify gene mutation linked to anaplastic oligodendroglioma

Published on June 12, 2015 at 9:23 AM · 

Scientists have identified a gene mutation linked to the development of an aggressive form of brain cancer.

Researchers found that errors in a gene known as TCF12 - which plays a key role in the formation of the embryonic brain are associated with more aggressive forms of a disease called anaplastic oligodendroglioma.

The new research is the largest ever genetic study of oligodendrogliomas, and provides important insights into their causes - and how they might be treated.

Oligodendrogliomas are fast-growing cancers that account for around 5-10 per cent of all tumours of the brain and central nervous system, and typically have a very poor prognosis.

Researchers at The Institute of Cancer Research, London, in collaboration with laboratories in France and Canada, compared the genetic sequence of 134 of these brain tumours with the DNA of healthy cells.

The study was largely funded by Investissements d'avenir and Génome Québec, with support from Cancer Research UK, and was published in the journal Nature Communications.

Researchers identified mutations in the TCF12 gene in 7.5 per cent of anaplastic oligodendrogliomas. They found that this subset of cancers grew more rapidly, and in other ways seemed more aggressive, than those where the gene was intact.

TCF12 is the genetic code for a protein that binds to DNA and controls the activity of other genes. The researchers found that mutations in TCF12 rendered the protein less able to bind to DNA, and this in turn led to a reduction in activity of other key genes - including one already associated with cancer spread, known as CHD1.

The researchers initially read the DNA sequence of 51 tumours and went on to look for TCF12 mutations in an additional group of 83.

The researchers also discovered errors in the gene IDH1 in 78 per cent of the tumours, confirming the findings of an initial scan of the data.

Finding out more about what genetic faults cause anaplastic oligodendrogliomas will allow scientists and clinicians to develop new personalised therapies that target a range of the mutations driving the disease.

Professor Richard Houlston, Professor of Molecular and Population Genetics at The Institute of Cancer Research, London, said:

"Our in-depth study has set out many of the genetic defects that cause this rare but highly aggressive form of brain cancer - including identifying a gene mutation that appears in particularly fast-growing forms.

"Anaplastic oligodendrogliomas are difficult to remove by surgery and don't respond well to other forms of treatment. We hope this new information might be used to discover new targeted therapies, offering patients a better chance at survival from this aggressive cancer."

Source:

Institute of Cancer Research

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por cyto às 11:46

Sábado, 04.07.15

way to stop growth of cancer cells by targeting the Warburg Effect

SLU researchers find way to stop growth of cancer cells by targeting the Warburg Effect

Published on June 26, 2015 at 10:55 PM 

In research published in Cancer Cell, Thomas Burris, Ph.D., chair of pharmacology and physiology at Saint Louis University, has, for the first time, found a way to stop cancer cell growth by targeting the Warburg Effect, a trait of cancer cell metabolism that scientists have been eager to exploit.

Unlike recent advances in personalized medicine that focus on specific genetic mutations associated with different types of cancer, this research targets a broad principle that applies to almost every kind of cancer: its energy source.

The Saint Louis University study, which was conducted in animal models and in human tumor cells in the lab, showed that a drug developed by Burris and colleagues at Scripps Research Institute can stop cancer cells without causing damage to healthy cells or leading to other severe side effects.

The Warburg Effect

Metabolism -- the ability to use energy -- is a feature of all living things. Cancer cells aggressively ramp up this process, allowing mutated cells to grow unchecked at the expense of surrounding tissue.

"Targeting cancer metabolism has become a hot area over the past few years, though the idea is not new," Burris said.

Since the early 1900s, scientists have known that cancer cells prefer to use glucose as fuel even if they have plenty of other resources available. In fact, this is how doctors use PET (positron emission tomography) scan images to spot tumors. PET scans highlight the glucose that cancer cells have accumulated.

This preference for using glucose as fuel is called the Warburg effect, or glycolysis.

In his paper, Burris reports that the Warburg effect is the metabolic foundation of oncogenic (cancer gene) growth, tumor progression and metastasis as well as tumor resistance to treatment.

Cancer's goal: to grow and divide

Cancer cells have one goal: to grow and divide as quickly as possible. And, while there are a number of possible molecular pathways a cell could use to find food, cancer cells have a set of preferred pathways.

"In fact, they are addicted to certain pathways," Burris said. "They need tools to grow fast and that means they need to have all of the parts for new cells and they need new energy."

"Cancer cells look for metabolic pathways to find the parts to grow and divide. If they don't have the parts, they just die," said Burris. "The Warburg effect ramps up energy use in the form of glucose to make chemicals required for rapid growth and cancer cells also ramp up another process, lipogenesis, that lets them make their own fats that they need to rapidly grow."

If the Warburg effect and lipogenesis are key metabolic pathways that drive cancer progression, growth, survival, immune evasion, resistance to treatment and disease recurrence, then, Burris hypothesizes, targeting glycolysis and lipogenesis could offer a way to stop a broad range of cancers.

Cutting off the energy supply

Burris and his colleagues created a class of compounds that affect a receptor that regulates fat synthesis. The new compound, SR9243, which started as an anti-cholesterol drug candidate, turns down fat synthesis so that cells can't produce their own fat. This also impacts the Warburg pathway, turning cancer cells into more normal cells. SR9243 suppresses abnormal glucose consumption and cuts off cancer cells' energy supply.

When cancer cells don't get the parts they need to reproduce through glucose or fat, they simply die.

Because the Warburg effect is not a feature of normal cells and because most normal cells can acquire fat from outside, SR9243 only kills cancer cells and remains non-toxic to healthy cells.

The drug also has a good safety profile; it is effective without causing weight loss, liver toxicity, or inflammation.

Promising Results So far, SR9243 has been tested in cultured cancer cells and in human tumor cells grown in animal models. Because the Warburg pathway is a feature of almost every kind of cancer, researchers are testing it on a number of different cancer models.

"It works in a wide range of cancers both in culture and in human tumors developing in animal models," Burris said. "Some are more sensitive to it than others. In several of these pathways, cells had been reprogramed by cancer to support cancer cell growth. This returns the metabolism to that of more normal cells."

In human tumors grown in animal models, Burris said, "It worked very well on lung, prostate, and colorectal cancers, and it worked to a lesser degree in ovarian and pancreatic cancers."

It also seems to work on glioblastoma, an extremely difficult to treat form of brain cancer, though it isn't able to cross the brain/blood barrier very effectively. The challenge for researchers in this scenario will be to find a way to allow the drug to cross this barrier, the body's natural protection for the brain, which can make it difficult for drug treatments to reach their target.

And, in even more promising news, it appears that when SR9243 is used in combination with existing chemotherapy drugs, it increases their effectiveness, in a mechanism apart from SR9243's own cancer fighting ability.

Source:

Saint Louis University

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por cyto às 11:25

Terça-feira, 23.06.15

NW Bio releases promising new data on DCVax-Direct Phase I trial for inoperable solid tumors

NW Bio releases promising new data on DCVax-Direct Phase I trial for inoperable solid tumors

Published on June 2, 2015 at 10:00 AM · 

Northwest Biotherapeutics (NASDAQ: NWBO) ("NW Bio"), a U.S. biotechnology company developing DCVax® personalized immune therapies for solid tumor cancers, over the weekend in Chicago released promising new data on their Phase I trial of DCVax-Direct for direct injection into all types of inoperable solid tumors.

The patients enrolled in the trial had late stage cancers, with an average of three inoperable tumors. The patients had failed multiple prior therapies and had a poor prognosis.

The trial enrolled 40 patients, and 39 were evaluable. A conservative treatment regimen was used. Although the patients had multiple inoperable tumors, only 1 tumor was injected with DCVax-Direct. The treatments included only 3 injections in the first 2 weeks (Day 0, 7 and 14), and up to 3 additional injections spaced months apart thereafter (Weeks 8, 16 and 32), over a total period of 8 months.

Patients typically received their first injection about 1-1/2 months after recruitment. Four patients are still in the process of completing the study visits, and data collection is ongoing on all of the patients.

The trial tested three different dose levels of DCVax-Direct, two different methods of activating the dendritic cells that comprise DCVax-Direct, and a dozen different cancers. Findings to date include encouraging survival data and substantial induction of immune checkpoint expression (PDL-1).

The webcast and presentation by Dr. Bosch can be found on the Company's website at nwbio.com/webcast

Findings to date include the following:

  • 27 of 39 patients are still alive at up to 18 months after first injection.
  • Patient survival correlates with the method of dendritic cell activation used. With the preferred method, 18 of 21 patients are still alive.
  • Treatment effects have been observed in diverse cancers, including lung, breast, colorectal, pancreatic, sarcoma, melanoma, neuro-endocrine and other cancers.
  • Patient survival correlates with the number of DCVax-Direct injections.
  • Patient survival also correlates with stabilization of disease at Week 8 (4th injection visit). Among patients treated with the preferred method of dendritic cell activation, 16 of 19 achieved stable disease (i.e., less than 25% increase in tumor size from baseline) at Week 8.

Findings to date relating to immunological responses include the following:

  • Induction of PDL-1 immune checkpoint expression was seen in 64% of evaluable patients (14 of 22) following DCVax-Direct treatment. This suggests that the tumors are putting up defenses against the immune responses induced by DCVax-Direct, and marks these patients as potential candidates for treatment with checkpoint inhibitor therapies.
  • An increase in T-cell infiltration into tumors, by functionally active T-cells, was seen following DCVax-Direct treatment.
  • Both local effects (in the injected tumor) and systemic effects were observed.

Based on the findings from the Phase I trial, the Company plans to enhance its Phase II trials in several ways, including by:

  • Using only the preferred activation method of the DCVax dendritic cells.
  • Injecting multiple inoperable tumors at each treatment visit, not just one.
  • Providing more frequent treatments and a larger total number of treatments.

The Company plans to pursue Phase II trials in non-small cell lung cancer and sarcoma, as well as a Phase II trial for multiple diverse types of cancers similar to the Phase I study. The Company also plans to expand the trial sites to include countries beyond the U.S.

"We are quite encouraged to see these results across diverse types of cancers, in late stage patients with multiple inoperable tumors who have exhausted other treatment options, and with quite a conservative DCVax-Direct treatment regimen," commented Linda Powers, CEO of NW Bio. "We are looking forward to proceeding with Phase II trials applying the lessons learned from this informative Phase I trial."

Source:

Northwest Biotherapeutics, Inc.

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por cyto às 17:20


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