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Research from Rutgers Cancer Institute of New Jersey shows administering the immunotherapy drug pembrolizumab together with chemotherapy given at the same time as radiation treatment (chemoradiation) is safe and tolerable as a first-line therapy for patients with stage 3 non-small cell lung cancer (NSCLC). The work, stemming from a multi-center phase 1 clinical trial led by Rutgers Cancer Institute, is published in the February 20 online edition of JAMA Oncology.

“Locally advanced NSCLC accounts for 20 to 25 percent of all new diagnoses of NSCLC, with five-year overall survival rates of between 25 to 30 percent when standard therapy is given. Current standard treatment in which an immunotherapy drug is administered after chemoradiaton offers a 57 percent progression-free survival rate compared to 43.5 percent when chemoradiation is given alone. Our team wanted to examine the safety and tolerability of the immunotherapy drug pembrolizumab when administered concurrently with chemoradiation, as we’ve learned from first-line treatment of stage 4 disease that we see better patient outcomes the earlier immunotherapy is given,” shares Rutgers Cancer Institute radiation oncologist Salma Jabbour, MD, who is the lead and corresponding author of the current work.

Typically, the human body’s immune system recognizes abnormal cells in the body and destroys them. Cancer cells frequently create proteins (PD-L1, programmed cell death ligand-1) on the cell surface that act as signals to turn off this part of the immune system. Pembrolizumab is a drug approved by the Food and Drug Administration to treat melanoma and other forms of cancer that targets PD-1 receptors, which act as a signaling ‘switch.’ Pembrolizumab blocks this action and turns the ‘switch’ back on, allowing the immune system to recognize cancer cells as foreign and attack them.

For a 27 month period between 2016 and 2018, 23 participants were enrolled (52 percent were women; median age 69 years). Five cohorts evaluating different timing and dosing of pembrolizumab combined with chemotherapy (carboplatin and paclitaxel weekly) and definitive radiation therapy (60 Gy in 2 Gy/day x 30 fractions) for unresectable, locally advanced, stage 3 disease were examined. Median follow-up time was 16 months.

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Results show the combined treatment is feasible and well tolerated with a 12-month progression-free survival of 69.7 percent. Clinical benefit accounted for 94.6 percent at a median of 12.6 months. Of 19 evaluable patients (those who received 2 or more cycles of pembrolizumab) for response, the best response to therapy was a partial response seen in 73.7 percent, followed by 15.8 percent with a complete response, and 5.3 percent with stable disease. Local progression occurred in one patient, and of the six who developed metastatic disease, the median time to metastatic disease was 14.7 months. While there was an increased rate of pneumonitis, the authors note that patients with this form of lung inflammation responded to high-dose steroid treatment.

This study demonstrates that the combination of immunotherapy with chemoradiation has the potential to improve cure rates for patients with stage 3 non-small cell lung cancer.”

Dr. Salma Jabbour, professor of radiation oncology at Rutgers Robert Wood Johnson Medical School

Given the risk of pneumonitis when pembrolizumab is given with chemoradiation, the authors note further evaluation of the treatment combination through clinical trials is warranted, where careful radiation design to limit key lung parameters and biomarkers can be implemented. They add study limitations include the small sample size and limited follow-up duration.

Source:

Rutgers Cancer Institute of New Jersey

Journal reference:

Jabbour, S.K, et al. (2020) Phase 1 Trial of Pembrolizumab Administered Concurrently With Chemoradiotherapy for Locally Advanced Non–Small Cell Lung Cancer. JAMA Oncology. doi.org/10.1001/jamaoncol.2019.6731.

Using cutting-edge imaging technology, researchers at Massachusetts General Hospital (MGH) have shown that the brains of young men with autism spectrum disorder (ASD) have low levels of a protein that appears to play a role in inflammation and metabolism. This surprising discovery, which published online today in the journal Molecular Psychiatry provides an important new insight into the possible origins of ASD, which affects one in 59 children.

ASD is a developmental disorder that emerges in early childhood and is characterized by difficulty communicating and interacting with others. While the cause is unknown, growing evidence has linked ASD to inflammation of brain tissue, or neuroinflammation. One sign of neuroinflammation is elevated levels of a substance called translocator protein (TSPO), which can be measured and located in the brain using positron-emission tomography (PET) and anatomical magnetic resonance imaging (MRI). The MGH study, led by Nicole Zurcher, PhD, an investigator in MGH's Athinoula A. Martinos Center for Biomedical Imaging, was the first to use a new generation of PET "tracers," which more accurately detect TSPO, to examine the brains of people with ASD.

In the study, Zurcher and her colleagues scanned the brains of 15 young adult males (average age, 24) with ASD. The group included both high- and low-functioning subjects with varying degrees of intellectual abilities. For comparison, Zurcher's team scanned the brains of 18 healthy control subjects who were similar in age. The investigators hypothesized that the scans would show increased levels, or expression, of TSPO in subjects who have ASD.

"To our surprise, that's not what we saw," says Zurcher. Instead, the scans showed that the brains of males with ASD had lower levels of TSPO than those of the healthy subjects. In fact, the men with the most severe symptoms of ASD tended to have the lowest expression of TSPO. When the tests were repeated several months later, the pattern persisted. The brain regions found to have low expression of TSPO have previously been linked to ASD in earlier studies, and are believed to govern social and cognitive capacities such as processing of emotions, interpreting facial expressions, empathy, and relating to others. "We know these brain regions are involved in autism," says Zurcher.

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To understand this unexpected finding, Zurcher notes that TSPO does more than serve as a marker of inflammation. "It has multiple complex roles," she says, and some actually promote brain health. For example, adequate TSPO is necessary for normal functioning of mitochondria, which are the "power houses" in cells that produce energy. Earlier research has linked malfunctioning mitochondria in brain cells to ASD.

Zurcher and her colleagues next plan to study brains from deceased donors with the goal of determining which brain cells in people with ASD might experience mitochondrial dysfunction, which she says may well be occurring alongside neuroinflammation and other mechanisms to cause ASD.

Our study has generated new hypotheses that now need to be investigated. There's more work to be done."

Nicole Zurcher, PhD, investigator, MGH's Athinoula A. Martinos Center for Biomedical Imaging

Source:

Massachusetts General Hospital

Journal reference:

Zürcher, N.R., et al. (2020) [11C]PBR28 MR–PET imaging reveals lower regional brain expression of translocator protein (TSPO) in young adult males with autism spectrum disorder. Molecular Psychiatry. doi.org/10.1038/s41380-020-0682-z.