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Archive for the ‘Genomics Pharmacy’ Category


Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

Researchers have embraced CRISPR gene-editing as a method for altering genomes, but some have reported that unwanted DNA changes may slip by undetected. The tool can cause large DNA deletions and rearrangements near its target site on the genome. Such alterations can confuse the interpretation of experimental results and could complicate efforts to design therapies based on CRISPR. The finding is in line with previous results from not only CRISPR but also other gene-editing systems.

 

CRISPR -Cas9 gene editing relies on the Cas9 enzyme to cut DNA at a particular target site. The cell then attempts to reseal this break using its DNA repair mechanisms. These mechanisms do not always work perfectly, and sometimes segments of DNA will be deleted or rearranged, or unrelated bits of DNA will become incorporated into the chromosome.

 

Researchers often use CRISPR to generate small deletions in the hope of knocking out a gene’s function. But when examining CRISPR edits, researchers found large deletions (often several thousand nucleotides) and complicated rearrangements of DNA sequences in which previously distant DNA sequences were stitched together. Many researchers use a method for amplifying short snippets of DNA to test whether their edits have been made properly. But this approach might miss larger deletions and rearrangements.

 

These deletions and rearrangements occur only with gene-editing techniques that rely on DNA cutting and not with some other types of CRISPR modifications that avoid cutting DNA. Such as a modified CRISPR system to switch one nucleotide for another without cutting DNA and other systems use inactivated Cas9 fused to other enzymes to turn genes on or off, or to target RNA. Overall, these unwanted edits are a problem that deserves more attention, but this should not stop anyone from using CRISPR. Only when people use it, they need to do a more thorough analysis about the outcome.

 

References:

 

https://www.nature.com/articles/d41586-018-05736-3?utm_source=briefing-dy

 

https://www.ncbi.nlm.nih.gov/pubmed/28561021

 

https://www.ncbi.nlm.nih.gov/pubmed/30010673

 

https://www.ncbi.nlm.nih.gov/pubmed/24651067

 

https://www.ncbi.nlm.nih.gov/pubmed/25398350

 

https://www.ncbi.nlm.nih.gov/pubmed/24838573

 

https://www.ncbi.nlm.nih.gov/pubmed/25200087

 

https://www.ncbi.nlm.nih.gov/pubmed/25757625

 

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Acute Coronary Syndrome (ACS): Strategies in Anticoagulant Selection: Diagnostics Approaches – Genetic Testing Aids vs. Biomarkers (Troponin types and BNP)

Curator: Aviva Lev-Ari, PhD, RN

UPDATED on 8/7/2018

Siemens’ high-sensitivity Troponin I (TnIH) assaysgot FDA clearance for use in diagnosing acute myocardial infarction. (Cardiovascular Business) The first high-sensitivity Troponin T test was cleared last year, as MedPage Today reported.

SOURCE

https://www.medpagetoday.com/cardiology/prevention/74423?xid=nl_mpt_cardiobreak2018-08-06&eun=g99985d0r&utm_source=Sailthru&utm_medium=email&utm_campaign=CardioBreak_080618&utm_term=SM%20CardioBreak%20Alert

UPDATED on 3/17/2018

An NT-proBNP <300 pg/ml strongly excludes the presence of acute HF.

J Am Coll Cardiol. 2018 Mar 20;71(11):1191-1200. doi: 10.1016/j.jacc.2018.01.021.

N-Terminal Pro-B-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study

 

A breakthrough in emergence of

  • Genetic Testing Aids as a Personalized approach, genomics-based approach to selecting antiplatelet therapy, for reduction in ischemic and bleeding events, and
  • Biochemical Biomarker approaches for dosing anti-thrombotic drugs are presented here.

“This study fills in a part of the puzzle of genomic testing,” said Craig Beavers, PharmD, of the University of Kentucky in Lexington. “It shows we can use genomic information in clinical decision making. It was interesting that there appeared to be a change in prescribing based on genomics.”

SOURCE

https://www.medpagetoday.com/meetingcoverage/acc/71722?xid=nl_mpt_DHE_2018-03-13&eun=g99985d0r&pos=3&utm_source=Sailthru&utm_medium=email&utm_campaign=Daily%20Headlines%202018-03-13&utm_term=Daily%20Headlines%20-%20Active%20User%20-%20180%20days

At 12 months, 25.9% of patients receiving standard care had experienced the trial’s primary composite endpoint — cardiovascular death, non-fatal MI or stroke, and Bleeding Academic Research Consortium (BARC) 3-5 major bleeding — compared with 15.8% of patients receiving an anticoagulant drug on the basis of genetic testing (P<0.001), reported Diego Ardissino, MD, of Azienda Ospedaliero-Universitaria di Parma in Italy, and colleagues.

PHARMCLO is the first trial to combine clinical characteristics with genetic information to inform the choice of P2Y12 receptor antagonist in patients with ACS, Ardissino said in a presentation at the American College of Cardiology annual meeting. The study was simultaneously published in the Journal of the American College of Cardiology.

“Selecting treatment on the basis of genetic data in addition to considerations concerning the patients’ clinical characteristics may lead to a more personalized, and therefore more efficient, antiplatelet therapy, thus reducing both ischemic and bleeding risk,” he said. “PHARMCLO is the first step of a new approach that will see a shift in emphasis away from trying to discover ever-more potent anti-thrombotic drugs, and toward ensuring that the right therapy is given to each individual patient.”

However, PHARMCLO was halted after about a fourth of the intended population was recruited. The Ethics Committee of Modena (Italy) required the trial to be prematurely stopped because of a lack of in vitro diagnosis certification for the testing instruments. The original patients were still followed, Ardissino stated.

The authors enrolled 888 patients, and randomly assigned them to be tested for

  • three genes associated with resistance to clopidogrel (Plavix), and then were assigned a
  • treatment based on clinical data informed by the testing results.
  • Tested genes were ABCB1, 2C19*2 and 2C19*17 with the STQ3 system.
  • Another group was assigned to treatment without reference to genetic testing.
  • Standard of care treatment was with Clopidogrel, Ticagrelor (Brilinta), or Prasugrel (Effient).
  1. Clopidogrel was more frequently used in the standard arm (50.7% versus 43.3%), while
  2. Ticagrelor in the pharmacogenomic arm (42.6% versus 32.7%, P<0.05) and
  3. Prasugrel were used equally in both.

The primary endpoint hazard ratio was 0.58 versus the standard arm (95% CI 0.43-0.78, P<0.001).

Previous studies have shown Prasugrel and Ticagrelor to be superior to Clopidogrel at preventing ischemic events. However, prasugrel and ticagrelor, which are more potent, are also known to increase the risk of bleeding. The findings suggest that having more information about a specific patient’s likely response to clopidogrel can help doctors weigh this trade-off, Ardissino said.

 SOURCES

The STANDARD OF CARE in Diagnosis of Acute Coronary Syndrome (ACS) using BioMarkers in serum blood relays of values of Troponin types and BNP for dosing anti-thrombotic drugs.

The team at LPBI Group published the following articles on this topic:

A search into our Journal Archive for “Acute Coronary Syndrome” yielded 210 articles

https://pharmaceuticalintelligence.com/?s=Acute+Coronary+Syndrome

  1. High Sensitivity Troponin (hs cTn) Assays 

  • Previously undiscerned value of hs-troponin

Curators: Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/06/18/previously-undiscerned-value-of-hs-troponin/

  • Recent Insights into the High Sensitivity Troponins for Acute Coronary Syndromes

Curator: Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2014/09/08/recent-insights-into-the-high-sensitivity-troponins-for-acute-coronary-syndromes/

  • Dealing with the Use of the High Sensitivity Troponin (hs cTn) Assays: Preparing the United States for High-Sensitivity Cardiac Troponin Assays

Author and Curator: Larry H Bernstein, MD, FCAP and Author and Curator: Aviva Lev-Ari, PhD, RD

https://pharmaceuticalintelligence.com/2013/05/18/dealing-with-the-use-of-the-hs-ctn-assays/

  • Preparing the United States for High-Sensitivity Cardiac Troponin Assays

Curator: Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2013/06/13/high-sensitivity-cardiac-troponin-assays/

 

2. BNP and proBNP

Brain natriuretic peptide (BNP), also known as B-type natriuretic peptide, is a hormone secreted by cardiomyocytes in the heart ventricles in response to stretching caused by increased ventricular blood volume, decrease in systemic vascular resistance and central venous pressure as well as an increase in natriuresis. The net effect of these peptides is a decrease in blood pressure due to the decrease in systemic vascular resistance and, thus, afterload. Additionally, the actions of both BNP and ANP result in a decrease in cardiac output due to an overall decrease in central venous pressure and preload as a result of the reduction in blood volume that follows natriuresis and diuresis.

SOURCE

Maisel A, Krishnaswamy P, Nowak R, McCord J, Hollander J, Duc P, Omland T, Storrow A, Abraham W, Wu A, Clopton P, Steg P, Westheim A, Knudsen C, Perez A, Kazanegra R, Herrmann H, McCullough P (2002). “Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure“. N Engl J Med347 (3): 161–7. 

 

The team at LPBI Group published the following articles on this topic:

  • Effect of Coronary Atherosclerosis and Myocardial Ischemia on Plasma Levels of High-Sensitivity Troponin T and NT-proBNP in Patients With Stable Angina

https://pharmaceuticalintelligence.com/2016/02/17/effect-of-coronary-atherosclerosis-and-myocardial-ischemia-on-plasma-levels-of-high-sensitivity-troponin-t-and-nt-probnp-in-patients-with-stable-angina/

  • More on the Performance of High Sensitivity Troponin T and with Amino Terminal Pro BNP in Diabetes

Writer and Curator: Larry H. Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2014/01/20/more-on-the-performance-of-high-sensitivity-troponin-t-and-with-amino-terminal-pro-bnp-in-diabetes/

  • Erythropoietin (EPO) and Intravenous Iron (Fe) as Therapeutics for Anemia in Severe and Resistant CHF: The Elevated N-terminal proBNP Biomarker

Co-Author of the FIRST Article: Larry H. Bernstein, MD, FCAP. Reviewer and Curator of the SECOND and of the THIRD Articles: Larry H. Bernstein, MD, FCAP and Article Architecture Curator: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2013/12/10/epo-as-therapeutics-for-anemia-in-chf/

  • Highlights of LIVE Day 1: World Medical Innovation Forum – CARDIOVASCULAR • MAY 1-3, 2017  BOSTON, MA • UNITED STATES

Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2017/05/01/highlights-of-live-day-1-world-medical-innovation-forum-cardiovascular-%E2%80%A2-may-1-3-2017-boston-ma-%E2%80%A2-united-states/

 

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Pharmacotyping Pancreatic Cancer Patients in the Future: Two Approaches – ORGANOIDS by David Tuveson and Hans Clevers and/or MICRODOSING Devices by Robert Langer

Curator: Aviva Lev-Ari, PhD, RN

 

UPDATED on 4/5/2018

Featured video: Magical Bob

A fascination with magic leads Institute Professor Robert Langer to solve world problems using the marvels of chemical engineering.Watch Video

MIT News Office
March 27, 2018

http://news.mit.edu/2018/featured-video-magical-bob-langer-0327

 

This curation provides the resources for edification on Pharmacotyping Pancreatic Cancer Patients in the Future

 

  • Professor Hans Clevers at Clevers Group, Hubrecht University

https://www.hubrecht.eu/onderzoekers/clevers-group/

  • Prof. Robert Langer, MIT

http://web.mit.edu/langerlab/langer.html

Langer’s articles on Drug Delivery

https://scholar.google.com/scholar?q=Langer+on+Drug+Delivery&hl=en&as_sdt=0&as_vis=1&oi=scholart&sa=X&ved=0ahUKEwixsd2w88TTAhVG4iYKHRaIAvEQgQMIJDAA

organoids, which I know you’re pretty involved in with Hans Clevers. What are your plans for organoids of pancreatic cancer?

Organoids are a really terrific model of a patient’s tumour that you generate from tissue that is either removed at the time of surgery or when they get a small needle biopsy. Culturing the tissue and observing an outgrowth of it is usually successful and when you have the cells, you can perform molecular diagnostics of any type. With a patient-derived organoid, you can sequence the exome and the RNA, and you can perform drug testing, which I call ‘pharmacotyping’, where you’re evaluating compounds that by themselves or in combination show potency against the cells. A major goal of our lab is to work towards being able to use organoids to choose therapies that will work for an individual patient – personalized medicine.

Organoids could be made moot by implantable microdevices for drug delivery into tumors, developed by Bob Langer. These devices are the size of a pencil lead and contain reservoirs that release microdoses of different drugs; the device can be injected into the tumor to deliver drugs, and can then be carefully dissected out and analyzed to gain insight into the sensitivity of cancer cells to different anticancer agents. Bob and I are kind of engaged in a friendly contest to see whether organoids or microdosing devices are going to come out on top. I suspect that both approaches will be important for pharmacotyping cancer patients in the future.

From the science side, we use organoids to discover things about pancreatic cancer. They’re great models, probably the best that I know of to rapidly discover new things about cancer because you can grow normal tissue as well as malignant tissue. So, from the same patient you can do a comparison easily to find out what’s different in the tumor. Organoids are crazy interesting, and when I see other people in the pancreatic cancer field I tell them, you should stop what you’re doing and work on these because it’s the faster way of studying this disease.

SOURCE

Other related articles on Pancreatic Cancer and Drug Delivery published in this Open Access Online Scientific Journal include the following:

 

Pancreatic Cancer: Articles of Note @PharmaceuticalIntelligence.com

Curator: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/05/26/pancreatic-cancer-articles-of-note-pharmaceuticalintelligence-com/

Keyword Search: “Pancreatic Cancer” – 275 Article Titles

https://pharmaceuticalintelligence.wordpress.com/wp-admin/edit.php?s=Pancreatic+Cancer&post_status=all&post_type=post&action=-1&m=0&cat=0&paged=1&action2=-1

Keyword Search: Drug Delivery: 542 Articles Titles

https://pharmaceuticalintelligence.wordpress.com/wp-admin/edit.php?s=Drug+Delivery&post_status=all&post_type=post&action=-1&m=0&cat=0&paged=1&action2=-1

Keyword Search: Personalized Medicine: 597 Article Titles

https://pharmaceuticalintelligence.wordpress.com/wp-admin/edit.php?s=Personalized+Medicine&post_status=all&post_type=post&action=-1&m=0&cat=0&paged=1&action2=-1

  • Cancer Biology & Genomics for Disease Diagnosis, on Amazon since 8/11/2015

http://www.amazon.com/dp/B013RVYR2K

 

 

VOLUME TWO WILL BE AVAILABLE ON AMAZON.COM ON MAY 1, 2017

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

Scientists think excessive population growth is a cause of scarcity and environmental degradation. A male pill could reduce the number of unintended pregnancies, which accounts for 40 percent of all pregnancies worldwide.

 

But, big drug companies long ago dropped out of the search for a male contraceptive pill which is able to chemically intercept millions of sperm before they reach a woman’s egg. Right now the chemical burden for contraception relies solely on the female. There’s not much activity in the male contraception field because an effective solution is available on the female side.

 

Presently, male contraception means a condom or a vasectomy. But researchers from Center for Drug Discovery at Baylor College of Medicine, USA are renewing the search for a better option—an easy-to-take pill that’s safe, fast-acting, and reversible.

 

The scientists began with lists of genes active in the testes for sperm production and motility and then created knockout mice that lack those genes. Using the gene-editing technology called CRISPR, in collaboration with Japanese scientists, they have so far made more than 75 of these “knockout” mice.

 

They allowed these mice to mate with normal (wild type) female mice, and if their female partners don’t get pregnant after three to six months, it means the gene might be a target for a contraceptive. Out of 2300 genes that are particularly active in the testes of mice, the researchers have identified 30 genes whose deletion makes the male infertile. Next the scientists are planning a novel screening approach to test whether any of about two billion chemicals can disable these genes in a test tube. Promising chemicals could then be fed to male mice to see if they cause infertility.

 

Female birth control pills use hormones to inhibit a woman’s ovaries from releasing eggs. But hormones have side effects like weight gain, mood changes, and headaches. A trial of one male contraceptive hormone was stopped early in 2011 after one participant committed suicide and others reported depression. Moreover, some drug candidates have made animals permanently sterile which is not the goal of the research. The challenge is to prevent sperm being made without permanently sterilizing the individual.

 

As a better way to test drugs, Scientists at University of Georgia, USA are investigating yet another high-tech approach. They are turning human skin cells into stem cells that look and act like the spermatogonial cells in the testes. Testing drugs on such cells might provide more accurate leads than tests on mice.

 

The male pill would also have to start working quickly, a lot sooner than the female pill, which takes about a week to function. Scientists from University of Dundee, U.K. admitted that there are lots of challenges. Because, a women’s ovary usually release one mature egg each month, while a man makes millions of sperm every day. So, the male pill has to be made 100 percent effective and act instantaneously.

 

References:

 

https://www.technologyreview.com/s/603676/the-search-for-a-perfect-male-birth-control-pill/

 

https://futurism.com/videos/the-perfect-male-birth-control-pill-is-coming-soon/?utm_source=Digest&utm_campaign=c42fc7b9b6-EMAIL_CAMPAIGN_2017_03_20&utm_medium=email&utm_term=0_03cd0a26cd-c42fc7b9b6-246845533

 

http://www.telegraph.co.uk/women/sex/the-male-pill-is-coming—and-its-going-to-change-everything/

 

http://www.mensfitness.com/women/sex-tips/male-birth-control-pill-making

 

http://health.howstuffworks.com/sexual-health/contraception/male-bc-pill.htm

 

http://europe.newsweek.com/male-contraception-side-effects-study-pill-injection-518237?rm=eu

 

http://edition.cnn.com/2016/01/07/health/male-birth-control-pill/index.html

 

http://www.nhs.uk/Conditions/contraception-guide/Pages/male-pill.aspx

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

MicroRNAs (miRNAs) are a group of small non-coding RNA molecules that play a major role in posttranscriptional regulation of gene expression and are expressed in an organ-specific manner. One miRNA can potentially regulate the expression of several genes, depending on cell type and differentiation stage. They control every cellular process and their altered regulation is involved in human diseases. miRNAs are differentially expressed in the male and female gonads and have an organ-specific reproductive function. Exerting their affect through germ cells and gonadal somatic cells, miRNAs regulate key proteins necessary for gonad development. The role of miRNAs in the testes is only starting to emerge though they have been shown to be required for adequate spermatogenesis. In the ovary, miRNAs play a fundamental role in follicles’ assembly, growth, differentiation, and ovulation.

 

Deciphering the underlying causes of idiopathic male infertility is one of the main challenges in reproductive medicine. This is especially relevant in infertile patients displaying normal seminal parameters and no urogenital or genetic abnormalities. In these cases, the search for additional sperm biomarkers is of high interest. This study was aimed to determine the implications of the sperm miRNA expression profiles in the reproductive capacity of normozoospermic infertile individuals. The expression levels of 736 miRNAs were evaluated in spermatozoa from normozoospermic infertile males and normozoospermic fertile males analyzed under the same conditions. 57 miRNAs were differentially expressed between populations; 20 of them was regulated by a host gene promoter that in three cases comprised genes involved in fertility. The predicted targets of the differentially expressed miRNAs unveiled a significant enrichment of biological processes related to embryonic morphogenesis and chromatin modification. Normozoospermic infertile individuals exhibit a specific sperm miRNA expression profile clearly differentiated from normozoospermic fertile individuals. This miRNA cargo has potential implications in the individuals’ reproductive competence.

 

Circulating or “extracellular” miRNAs detected in biological fluids, could be used as potential diagnostic and prognostic biomarkers of several disease, such as cancer, gynecological and pregnancy disorders. However, their contributions in female infertility and in vitro fertilization (IVF) remain unknown. Polycystic ovary syndrome (PCOS) is a frequent endocrine disorder in women. PCOS is associated with altered features of androgen metabolism, increased insulin resistance and impaired fertility. Furthermore, PCOS, being a syndrome diagnosis, is heterogeneous and characterized by polycystic ovaries, chronic anovulation and evidence of hyperandrogenism, as well as being associated with chronic low-grade inflammation and an increased life time risk of type 2 diabetes. Altered miRNA levels have been associated with diabetes, insulin resistance, inflammation and various cancers. Studies have shown that circulating miRNAs are present in whole blood, serum, plasma and the follicular fluid of PCOS patients and that these might serve as potential biomarkers and a new approach for the diagnosis of PCOS. Presence of miRNA in mammalian follicular fluid has been demonstrated to be enclosed within microvesicles and exosomes or they can also be associated to protein complexes. The presence of microvesicles and exosomes carrying microRNAs in follicular fluid could represent an alternative mechanism of autocrine and paracrine communication inside the ovarian follicle. The investigation of the expression profiles of five circulating miRNAs (let-7b, miR-29a, miR-30a, miR-140 and miR-320a) in human follicular fluid from women with normal ovarian reserve and with polycystic ovary syndrome (PCOS) and their ability to predict IVF outcomes showed that these miRNAs could provide new helpful biomarkers to facilitate personalized medical care for oocyte quality in ART (Assisted Reproductive Treatment) and during IVF (In Vitro Fertilization).

 

References:

 

http://link.springer.com/chapter/10.1007%2F978-3-319-31973-5_12

 

http://onlinelibrary.wiley.com/doi/10.1111/andr.12276/abstract;jsessionid=F805A89DCC94BDBD42D6D60C40AD4AB0.f03t03

 

http://www.sciencedirect.com/science/article/pii/S0009279716302241

 

http://link.springer.com/article/10.1007%2Fs10815-016-0657-9

 

http://www.nature.com/articles/srep24976

 

 

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Postmarketing Safety or Effectiveness Data Needed: The 2013 paper was funded by the firm Sarepta Therapeutics, sellers of eteplirsen, a surge in its shares seen after the approval. Eteplirsen will cost patients around $300,000 a year.

 

Curator: Aviva Lev-Ari, PhD, RN

 

On September 19, the FDA okayed eteplirsen to treat Duchenne muscular dystrophy (DMD), a rare genetic disorder that results in muscle degeneration and premature death. Several of its top officials disagreed with the drug’s approval, questioning how beneficial it will be for patients, as ForbesMedPage Today and others reported.

http://retractionwatch.com/2016/09/21/amid-controversial-sarepta-approval-decision-fda-head-calls-for-key-study-retraction/

Factors at play for FDA Approval of eteplirsen

  1. the help of the families of young boys with Duchenne muscular dystrophy, emotional scenes from these families who have campaigned for so long
  2. an executive team from Sarepta who wouldn’t give up,

Ed Kaye, Sarepta, CEO – EK: It’s all about resilience. One of the things we’ve had is a group of people of like minds and anytime one of us gets down, somebody else is there to pick you up. One of the things we’ve always done is: Every time we’ve felt sorry for ourselves, we just need to think about those patients and what they go through. Our struggles in comparison very quickly become meaningless. You end up saying to yourself: What am I complaining about? Quit whining; get up and do your job.

and

3. an emerging new philosophy from some within the FDA, eteplirsen, now Exondys 51, was approved in patients with a confirmed mutation of the dystrophin gene amenable to exon 51 skipping.

http://www.fiercebiotech.com/biotech/sarepta-ceo-ed-kaye-fda-courage-nice-and-resilience?utm_medium=nl&utm_source=internal&mrkid=993697&mkt_tok=eyJpIjoiTXpBeU56aGpNREV3T1RZMiIsInQiOiJIM2poTkVOQ0N6YmxaenVHZDM1RlVvbTFmRkdwZGdxQ0pmYXNVOG5PKzRyenFXTkRMV0dcL3l0bVBPNkJ2NFV3Rnc3bWVFVnUwMCs3YVhWeVhvRkkrUU5FMFJ1RndSQTlHWFRnQmFTbUo3ODg9In0%3D

9/19/2016

FDA grants accelerated approval to first drug for Duchenne muscular dystrophy

The accelerated approval of Exondys 51 is based on the surrogate endpoint of dystrophin increase in skeletal muscle observed in some Exondys 51-treated patients. The FDA has concluded that the data submitted by the applicant demonstrated an increase in dystrophin production that is reasonably likely to predict clinical benefit in some patients with DMD who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping. A clinical benefit of Exondys 51, including improved motor function, has not been established. In making this decision, the FDA considered the potential risks associated with the drug, the life-threatening and debilitating nature of the disease for these children and the lack of available therapy.

The FDA granted Exondys 51 fast track designation, which is a designation to facilitate the development and expedite the review of drugs that are intended to treat serious conditions and that demonstrate the potential to address an unmet medical need. It was also granted priority review and orphan drug designationPriority review status is granted to applications for drugs that, if approved, would be a significant improvement in safety or effectiveness in the treatment of a serious condition. Orphan drug designation provides incentives such as clinical trial tax credits, user fee waiver and eligibility for orphan drug exclusivity to assist and encourage the development of drugs for rare diseases.

SOURCE

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm521263.htm

The viability of this drug approval depends  on “to be gathered” Postmarketing safety or effectiveness data, aka follow-up confirmatory trials.

Sarepta CEO Ed Kaye on FDA courage, NICE and resilience

BA: When it comes to flexibility, however, the FDA will likely not be flexible if your drug doesn’t prove the desired efficacy in your longer term postmarketing studies. If at the end of this period your drug doesn’t come through, how easy will it be for you to take this off the market? I don’t think anyone, including the FDA, wants a repeat of what happened in 2011 when Roche saw its breast cancer license for Avastin, which had been approved under an accelerated review, pulled after not being safe or effective enough in the follow-up confirmatory trials. But you face this as a possible scenario.

EK: That’s true, but one of the things we’re trying to do to mitigate that is to obviously, with our ongoing studies, prove the efficacy that the FDA wants to see. And you know, if there is a problem with one study then we’d hope to have other data that are supportive. The other thing we’re doing of course is developing that next-generation chemistry in DMD that could prove more effective, so we could certainly consider using that next-gen chemistry to take our work forward and try and make it better.

We have a lot of shots on goal to make sure we can continue to supply a product for these boys, but there is always a risk. If we can’t show efficacy in the way the FDA wants, then yes they have the option to take it off the market.

http://www.fiercebiotech.com/biotech/sarepta-ceo-ed-kaye-fda-courage-nice-and-resilience?utm_medium=nl&utm_source=internal&mrkid=993697&mkt_tok=eyJpIjoiTXpBeU56aGpNREV3T1RZMiIsInQiOiJIM2poTkVOQ0N6YmxaenVHZDM1RlVvbTFmRkdwZGdxQ0pmYXNVOG5PKzRyenFXTkRMV0dcL3l0bVBPNkJ2NFV3Rnc3bWVFVnUwMCs3YVhWeVhvRkkrUU5FMFJ1RndSQTlHWFRnQmFTbUo3ODg9In0%3D

Need for follow-up confirmatory trials remains outstanding

FDA’s Postmarketing Surveillance Programs

http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Surveillance/ucm090385.htm

FDA’s Regulations and Policies and Procedures for Postmarketing Surveillance Programs

http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Surveillance/ucm090394.htm

 

Positions on Sarepta’s eteplirsen Scientific Approach

Gene Editing for Exon 51: Why CRISPR Snipping might be better than Exon Skipping for DMD

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/01/23/gene-editing-for-exon-51-why-crispr-snipping-might-be-better-than-exon-skipping-for-dmd/

 

QUOTE START

Retraction Watch

Tracking retractions as a window into the scientific process

Amid controversial Sarepta approval decision, FDA head calls for key study retraction

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FDAThe head of the U.S. Food and Drug Administration (FDA) has called for the retraction of a study about a drug that the agency itself approved earlier this week, despite senior staff opposing the approval.

On September 19, the FDA okayed eteplirsen to treat Duchenne muscular dystrophy (DMD), a rare genetic disorder that results in muscle degeneration and premature death. Several of its top officials disagreed with the drug’s approval, questioning how beneficial it will be for patients, as ForbesMedPage Today and others reported.

In a lengthy report Commissioner Robert Califf sent to senior FDA officials on September 16 — that was made public on September 19 — he called for the retraction of a 2013 study published in Annals of Neurologyfunded by the seller of eteplirsen, which showed beneficial effects of the drug in DMD patients. Califf writes inthe report:

The publication, now known to be misleading, should probably be retracted by its authors.

In a footnote in the report, Califf adds:

In view of the scientific deficiencies identified in this analysis, I believe it would be appropriate to initiate a dialogue that would lead to a formal correction or retraction (as appropriate) of the published report.

The study was not the key factor in the agency’s decision to approve the drug, according to Steve Usdin, Washington editor of the publication BioCentury; still, Usdin told Retraction Watch he is “really surprised” at the call for retraction from top FDA staff, the first he has come across in the last two decades.

The 2013 paper was funded by the firm Sarepta Therapeutics, sellers of eteplirsen, which has seen a surge in its shares after the approval. Eteplirsen will cost patients around $300,000 a year.

DMD affects around 1 in 3,600 boys due to a mutation in the gene that codes for the protein dystrophin, which is important for structural stability of muscles. Eteplirsen is the first drug to treat DMD, and was initially given a green light by Janet Woodcock, director of Center for Drug Evaluation and Research, after a split vote from the FDA’s advisory committee. Despite Califf’s issues with the literature supporting the drug’s use in DMD, he did not overturn Woodcock’s decision, and the agency approved the drug this week.

In 2014, an inspection team visited the Nationwide Children’s Hospital in Columbus, Ohio, where the research was conducted, according to the report. In the report, Ellis Unger, director of the Office of Drug Evaluation I in FDA’s Center for Drug Evaluation, notes:

We found the analytical procedures to be typical of an academic research center, seemingly appropriate for what was simply an exploratory phase 1/2 study, but not suitable for an adequate and well controlled study aimed to serve as the basis for a regulatory action. The procedures and controls that one would expect to see in support of a phase 3 registrational trial were not in evidence.

Specifically, Unger describes concerns about blinding during the experiments, and notes:

The immunohistochemistry images were only faintly stained, and had been read by a single technician using an older liquid crystal display (LCD) computer monitor in a windowed room where lighting was not controlled. (The technician had to suspend reading around mid-day, when brighter light began to fill the room and reading became impossible.)

Unger adds:

Having uncovered numerous technical and operational shortcomings in Columbus, our team worked collaboratively with the applicant to develop improved methods for a reassessment of the stored images…This re-analysis, along with the study published in 2013, provides an instructive example of an investigation with extraordinary results that could not be verified.

Luciana Borio, acting chief scientist at the FDA, is cited in the report saying:

I would be remiss if I did not note that the sponsor has exhibited serious irresponsibility by playing a role in publishing and promoting selective data during the development of this product. Not only was there a misleading published article with respect to the results of Study–which has never been retracted—but Sarepta also issued a press release relying on the misleading article and its findings…As determined by the review team, and as acknowledged by Dr. Woodcock, the article’s scientific findings—with respect to the demonstrated effect of eteplirsen on both surrogate and clinical endpoints—do not withstand proper and objective analyses of the data. Sarepta’s misleading communications led to unrealistic expectations and hope for DMD patients and their families.

Here’s how Sarepta describes the study’s findings in the press release Borio refers to:

Published study results showed that once-weekly treatment with eteplirsen resulted in a statistically significant increase from baseline in novel dystrophin, the protein that is lacking in patients with DMD. In addition, eteplirsen-treated patients evaluable on the 6-minute walk test (6MWT) demonstrated stabilization in walking ability compared to a placebo/delayed-treatment cohort. Eteplirsen was well tolerated in the study with no clinically significant treatment-related adverse events. These data will form the basis of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for eteplirsen planned for the first half of 2014.

However, Usdin noted that the drug’s approval and the study are two independent events, adding that the 2013 study just “got the ball rolling” for eteplirsen, and the FDA conducted many of its own experiments analyses, as detailed in the newly released report.

Jerry Mendell, the corresponding author of the study (which has so far been cited 118 times, according to Thomson Reuters Web of Science) from Ohio State University in Columbus, told us the allegations were “unfounded” and said the data are “valid.” Therefore, he added, he will not be approaching the journal for a retraction, noting that the FDA asked him hundreds of questions about the paper and audited the trials.

Clifford Saper, the editor-in-chief of Annals of Neurology from the Beth Israel Deaconess Medical Center (which is part of Harvard Medical School), said in an email:

It takes more than a call by a politician for retraction of a paper. It takes actual evidence.

He added:

If the FDA commissioner has, or knows of someone who has, evidence for an error in a paper published in Annals of Neurology, I encourage him to send that evidence to me and a copy to the authors of the article, for their reply. At that point we will engage in a scientific review of the evidence and make appropriate responses.

Linda Lowes, sixth author of the present study, is the last author of a 2016 study in Physical Therapy that was retracted months after publication. Its notice reads:

This article has been retracted by the author due to unintentional deviations in the use of the described modified technique to assess plagiocephaly in the study participants, such that the use of the modified technique cannot be defended for the stated purpose in this population at this time.

Califf was a cardiologist at Duke University during the high-profile scandal of researcher Anil Potti at Duke, which led to more than 10 retractions, settled lawsuits, and medical board reprimands. In 2015, he told TheTriangle Business Journal:

I wish I had gotten myself more involved earlier…There were systems that were not adequate, as we stated. … That was a tough one, I think, for the whole institution.

We’ve contacted the FDA for comment, and will update the post with anything else we learn.

END QUOTE

Correction 9/21/16 10:44 p.m. eastern: When originally published, this post incorrectly reported that Califf was part of an inspection team that visited the Nationwide Children’s Hospital in Ohio, and attributed quotes from Ellis Unger to Califf. We have made appropriate corrections, and apologize for the error.

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SOURCE

http://retractionwatch.com/2016/09/21/amid-controversial-sarepta-approval-decision-fda-head-calls-for-key-study-retraction/

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Durable responses with checkpoint inhibitor

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Immunotherapy Active in ‘Universally Lethal’ Glioblastoma

ACTIVATE CME    by Kristin Jenkins 

  • Contributing Writer, MedPage Today

http://www.medpagetoday.com/HematologyOncology/BrainCancer/57641

 

Two pediatric siblings with recurrent multifocal glioblastoma multiforme (GBM) refractory to current standard therapies exhibited “remarkable and durable” responses to immune checkpoint inhibition with single-agent nivolumab (Opdivo), researchers said.

Following pre-clinical testing in 37 biallelic mismatch repair deficiency (bMMRD) cancers, a regimen of 3 mg/kg nivolumab every 2 weeks resulted in clinically significant responses and a profound radiologic response, Uri Tabori, MD, of The Hospital for Sick Children, Toronto, Ontario, Canada, and colleagues reported in the Journal of Clinical Oncology.

The 6-year-old white female patient and her 3.5-year-old brother resumed normal schooling and daily activities after 9 and 5 months of therapy, respectively, the researchers said.

“This observation is especially encouraging because these children are still clinically stable, whereas most relapsed pediatric GBMs will progress within 1 to 2 months despite salvage treatment, and survival is usually 3 to 6 months post-recurrence. It also highlights the utility of germline predisposition in guiding novel treatment options — in this case, immunotherapy — for cancer treatment.”

Findings from this lab study and small case series report may have implications for GBM as well as for other hypermutant cancers arising from primary (genetic predisposition) or secondary MMRD, the researchers said. “Given the increasing availability of commercial sequencing platforms, analysis of mutation burden and neoantigens can play a role in transforming treatment of these patients.”

Still, they added that these results, while encouraging, need to be validated in multinational prospective clinical trials of these “universally lethal” bMMRD-driven hypermutant cancers.

“Sometimes very small studies can yield meaningful results,” Robert Fenstermaker, MD, of Roswell Park Cancer Institute in Buffalo, N.Y., told MedPage Today via email. “Although anecdotal, the results of this study are quite encouraging because they tend to confirm current theory about immunotherapy for glioblastoma.”

Although these kinds of clinical responses to single-agent drug therapy in GBM are uncommon and the results may not be broadly applicable to all glioblastoma patients, this paper “is of much greater importance than just these few cases,” Fenstermaker emphasized. “The excellent responses in these particular cases suggest that an immune checkpoint inhibitor (nivolumab) may have enabled the immune system to respond fully.”

This “very small case series” report of a “compelling clinical experience” is a “fascinating and beautiful example of how mechanistic insight can be linked to rationally designed clinical applications — in turn, stimulating new downstream ideas,” Stephanie Weiss, MD, a radiation oncologist at Fox Chase Cancer Center in Philadelphia, commented in an email.

“This series also tests ‘proof of principle,’ that bMMRD tumors are hypermutated and associated with a high neoantigen load, and therefore may respond much like other immune checkpoint inhibitor-sensitive tumors. In this sense, the results reveal a tantalizing glimpse into the disease process of at least a subset of GBMs and can guide high-quality study of novel treatment for GBM.”

For the study, Tabori and colleagues performed exome sequencing and neoantigen prediction on 37 bMMRD-associated tumors, including 21 GBMs, and compared them with childhood and adult brain neoplasms.

The bMMRD GBMs were found to be hypermutant and to have an extremely strong neoantigen load — up to 16 times higher than the signature commonly seen in known immune checkpoint inhibitors (P<.001).

The female patient, diagnosed with a left parietal GBM, underwent near-total resection and focal irradiation over 6.5 weeks. After a clinical remission lasting 3 months, surveillance MRI revealed recurrence in the initial tumor bed and a second lesion in the left temporal lobe.

Six months earlier, the index patient’s brother had been diagnosed with a right frontoparietal GBM and treated with surgery, focal irradiation, and temozolomide (Temodal). Ten months after diagnosis, surveillance MRI revealed an asymptomatic diffuse multinodular GBM recurrence.

When given nivolumab as a last-resort therapeutic agent, both children initially experienced serious symptoms that on imaging mimicked tutor progression. After symptomatic management and observation, both stabilized, and follow-up imaging demonstrated significant improvement in tumor-related abnormalities.

Fenstermaker said that important next steps lie ahead, such as combining immune checkpoint inhibitors with specific cancer vaccines designed to immunize patients with glioblastomas other than this rare hypermutated type. “There are a number of prospective vaccines currently in the glioblastoma drug pipeline that would be candidates for this kind of approach,” he told MedPage Today. Examples include SurVaxM, NeoVax, HSPPC-96, and various dendritic cell vaccines.

In addition, newer genomic techniques are being developed that could make it possible to create a personalized profile of the mutant proteins in a given patient’s tumor, he noted. “One can imagine combining such a personalized vaccine against these mutant proteins together with an immune checkpoint inhibitor. Such a combination might result in many more responses like the ones seen in this small study.”

 

PD-1 Blockade in Tumors with Mismatch-Repair Deficiency

Dung T. Le, Jennifer N. Uram, Hao Wang, Bjarne R. Bartlett, Holly Kemberling, Aleksandra D. Eyring, et al.
http://www.nejm.org/doi/full/10.1056/NEJMoa1500596

BACKGROUND

Somatic mutations have the potential to encode “non-self” immunogenic antigens. We hypothesized that tumors with a large number of somatic mutations due to mismatch-repair defects may be susceptible to immune checkpoint blockade.

METHODS

We conducted a phase 2 study to evaluate the clinical activity of pembrolizumab, an anti–programmed death 1 immune checkpoint inhibitor, in 41 patients with progressive metastatic carcinoma with or without mismatch-repair deficiency. Pembrolizumab was administered intravenously at a dose of 10 mg per kilogram of body weight every 14 days in patients with mismatch repair–deficient colorectal cancers, patients with mismatch repair–proficient colorectal cancers, and patients with mismatch repair–deficient cancers that were not colorectal. The coprimary end points were the immune-related objective response rate and the 20-week immune-related progression-free survival rate.

RESULTS

The immune-related objective response rate and immune-related progression-free survival rate were 40% (4 of 10 patients) and 78% (7 of 9 patients), respectively, for mismatch repair–deficient colorectal cancers and 0% (0 of 18 patients) and 11% (2 of 18 patients) for mismatch repair–proficient colorectal cancers. The median progression-free survival and overall survival were not reached in the cohort with mismatch repair–deficient colorectal cancer but were 2.2 and 5.0 months, respectively, in the cohort with mismatch repair–proficient colorectal cancer (hazard ratio for disease progression or death, 0.10 [P<0.001], and hazard ratio for death, 0.22 [P=0.05]). Patients with mismatch repair–deficient noncolorectal cancer had responses similar to those of patients with mismatch repair–deficient colorectal cancer (immune-related objective response rate, 71% [5 of 7 patients]; immune-related progression-free survival rate, 67% [4 of 6 patients]). Whole-exome sequencing revealed a mean of 1782 somatic mutations per tumor in mismatch repair–deficient tumors, as compared with 73 in mismatch repair–proficient tumors (P=0.007), and high somatic mutation loads were associated with prolonged progression-free survival (P=0.02).

CONCLUSIONS

This study showed that mismatch-repair status predicted clinical benefit of immune checkpoint blockade with pembrolizumab. (Funded by Johns Hopkins University and others; ClinicalTrials.gov number, NCT01876511.)

Eric BouffetValérie LaroucheBrittany B. CampbellDaniele MericoRichard de Borja, et al.

Purpose Recurrent glioblastoma multiforme (GBM) is incurable with current therapies. Biallelic mismatch repair deficiency (bMMRD) is a highly penetrant childhood cancer syndrome often resulting in GBM characterized by a high mutational burden. Evidence suggests that high mutation and neoantigen loads are associated with response to immune checkpoint inhibition.

Patients and Methods We performed exome sequencing and neoantigen prediction on 37 bMMRD cancers and compared them with childhood and adult brain neoplasms. Neoantigen prediction bMMRD GBM was compared with responsive adult cancers from multiple tissues. Two siblings with recurrent multifocal bMMRD GBM were treated with the immune checkpoint inhibitor nivolumab.

Results All malignant tumors (n = 32) were hypermutant. Although bMMRD brain tumors had the highest mutational load because of secondary polymerase mutations (mean, 17,740 ± standard deviation, 7,703), all other high-grade tumors were hypermutant (mean, 1,589 ± standard deviation, 1,043), similar to other cancers that responded favorably to immune checkpoint inhibitors. bMMRD GBM had a significantly higher mutational load than sporadic pediatric and adult gliomas and all other brain tumors (P < .001). bMMRD GBM harbored mean neoantigen loads seven to 16 times higher than those in immunoresponsive melanomas, lung cancers, or microsatellite-unstable GI cancers (P < .001). On the basis of these preclinical data, we treated two bMMRD siblings with recurrent multifocal GBM with the anti–programmed death-1 inhibitor nivolumab, which resulted in clinically significant responses and a profound radiologic response.

Conclusion This report of initial and durable responses of recurrent GBM to immune checkpoint inhibition may have implications for GBM in general and other hypermutant cancers arising from primary (genetic predisposition) or secondary MMRD.

Glioblastoma multiforme (GBM) is a highly malignant brain tumor and the most common cause of death among children with CNS neoplasms.1 Despite primary management, which consists of surgical resection followed by radiation therapy and chemotherapy, most GBMs will recur, resulting in rapid death. Patients with recurrent disease have a particularly poor prognosis, with a median survival of fewer than 6 months; no effective therapies currently exist.

In contrast to adult CNS malignancies, a significant proportion of childhood brain tumors occur in the context of cancer predisposition syndromes.2 Pediatric GBMs are associated with germline mutations in TP53 (Li-Fraumeni syndrome)1 and the mismatch repair (MMR) genes (biallelic MMR deficiency syndrome [bMMRD]).3 Patients with bMMRD are unique in both the molecular events that lead to GBM formation and opportunities for innovative management of these tumors to possibly improve survival.

bMMRD is caused by homozygous germline mutations in one of the four MMR genes (PMS2, MLH1, MSH2, and MSH6) and is arguably the most penetrant cancer predisposition syndrome, with 100% of biallelic mutation carriers developing cancers in the first two decades of life. These are most commonly malignant gliomas, hematologic malignancies, and GI cancers.3,4 Understanding the relationship between the bMMRD somatic mutational landscape and tumor biology can lead to development of novel therapies and improved patient outcomes.

bMMRD GBMs harbor the highest mutation load among human cancers.5 Combined germline mutations in the MMR genes and somatic mutations in DNA polymerase result in complete ablation of proofreading during DNA replication and underpin this phenomenon. bMMRD GBMs, in contrast to other childhood cancers and adult MMR-proficient gliomas, exhibit a molecular signature characterized by single-nucleotide changes present in exponentially higher numbers. An important characteristic of non-bMMRD cancers exhibiting high mutation loads—subsets of malignant melanomas and lung, bladder, and microsatellite-unstable GI cancers—is responsiveness to immune checkpoint inhibitors.69

Checkpoint inhibitors target the immunomodulatory effect of CTLA-4 (cytotoxic T lymphocyte–associated protein 4) and programmed death-1 (PD-1)/programmed death-ligand 1, restoring effector T-cell function and antitumor activity. Recent reports have shown that patients whose tumors bear a high mutation load and/or definedtumor-associated antigen (neoantigen) signatures derive enhanced clinical benefit from checkpoint inhibitor therapy.10

Nivolumab is an anti–PD-1–directed immune checkpoint inhibitor approved for use in the treatment of non–small-cell lung cancer11and melanoma and under clinical investigation in multiple adult and pediatric tumors.12,13 However, this response is currently unknown in bMMRD-associated cancers and the uniformly lethal GBM.

 

Fig 1.

Fig 1.   Clinical and molecular features of the biallelic mismatch repair (MMR) deficiency (bMMRD) family. (A) Pedigree of the family with both bMMRD-affected children (solid square and circle). Both siblings presented with glioblastoma multiforme (GBM), whereas parents remained unaffected, as observed in other bMMRD families. (B) Immunohistochemistry staining of the index patient’s GBM for the four MMR genes: MSH2, MSH6,MLH1, and PMS2. A PMS2-negative stain in both tumor and normal cells prompted subsequent genetic testing that confirmed the diagnosis of bMMRD. NF1, neurofibromatosis type 1.   http://jco.ascopubs.org/content/early/2016/03/17/JCO.2016.66.6552/F1.small.gif

 

To examine whether immune checkpoint inhibitors would be applicable for bMMRD cancers, we surveyed the extent of hypermutation across bMMRD tumors form various tissues. Exome sequencing of 37 cancers collected from the bMMRD consortium revealed that all malignant tumors (n = 32) were hypermutant. Although bMMRD brain tumors had the highest mutational load resulting from secondary polymerase mutations (mean, 17,740 ± standard deviation [SD], 7,703), all other high-grade tumors were hypermutant, harboring more than 100 exonic mutations (mean, 1,589 ± SD, 1,043; Fig 2A). Lower-grade bMMRD tumors (n = 5) did not exhibit hypermutation (mean, 40 ± SD, 18). Importantly, bMMRD GBMs had a significantly higher mutational load than sporadic pediatric and adult gliomas and all other brain tumors (P < .001; Fig 2A). To test the extent to which hypermutation translates to a strong neoantigen signature, a current predictor of response to immune checkpoint inhibition, we performed genome-wide somatic neoepitope analysis using similar algorithms previously used for melanoma, lung, and colon cancers.9,14,15 For each study, we compared our cohort of tumors with other tumors that were reported to respond to immune checkpoint inhibitors (Fig 2B). Strikingly, bMMRD GBMs had a significantly higher number of predicted neoantigens, whereas other tumors responded with a fraction of the neoantigens found in our patients (P < .001; Fig 2B). The mean neoantigen load was seven to 16 times higher than those of immunoresponsive melanomas, lung cancers, and microsatellite-unstable GI cancers.

 

Fig 2.

Fig 2.  Tumor mutation and neoantigen analysis. (A) Boxplot comparing the number of mutations per tumor exome in several biallelic mismatch repair deficiency (bMMRD) cancer types with pediatric and adult brain tumors. (B) Ratio of the number of neoantigens found in immunoresponsive tumors from melanoma (n = 27), lung cancer (n = 14), and colon cancer (n = 7) data sets compared with median number of neoantigens in bMMRD glioblastoma multiforme (GBM; n = 13). ATRT, atypical teratoid rhabdoid tumor; DIPG, diffuse intrinsic pontine glioma; L/L, leukemia/lymphoma; LGG, low-grade glioma; MB, medulloblastoma; PA, pilocytic astrocytoma; PNET, primitive neuroectodermal tumor.

 

We describe two pediatric patients with recurrent multifocal GBM refractory to current standard therapies who exhibited remarkable and durable responses to immune checkpoint inhibition with single-agent nivolumab. This observation is especially encouraging because these children are still clinically stable, whereas most relapsed pediatric GBMs will progress within 1 to 2 months19 despite salvage treatment, and survival is usually 3 to 6 months postrecurrence.20 Furthermore, bMMRD GBMs have outcomes similar to those of sporadic childhood GBMs,21 and data gathered from the consortium reveal a mean time from relapse to death of 2.6 months in bMMRD GBM. To our knowledge, this is the first report of such a response in childhood or adult GBM. It also highlights the utility of germline predisposition in guiding novel treatment options—in this case, immunotherapy—for cancer treatment. ….

sjwilliamspa

Not sure if the link between PD-L1 response and MMR status is causal in this ase. there are many tumors with MMR and especially all tumors had high degree of MMR. Perhaps they need to look at tumors that have a more stable genome like certain hepatocarcinomas.

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