Feeds:
Posts
Comments

Posts Tagged ‘DNA Sequencing’

Nanotechnology, personalized medicine and DNA sequencing

Author, reporter, Curator: Tilda Barliya PhD

Dr. Ritu Saxena’s exciting report on the fascinating work of Dr. Apostolia M. Tsimberidou “personalized medicine gearing up to tackle cancer”, inspired me to go back and review this topic and see how nanotechnology can be applied in personalized medicine.

To read the Dr. Saxena’s post, please see http://pharmaceuticalintelligence.com/2013/01/07/personalized-medicine-gearing-up-to-tackle-cancer/

It is based on an interview with Dr. A. M. Tsimberidou based on her paper:

Personalized medicine in a phase I clinical trials program: the MD Anderson Cancer Center initiative.

http://www.ncbi.nlm.nih.gov/pubmed?term=22966018

In March 2011 Nature Reviews issued a special issue features discussions of the advances, challenges and progress in the field of personalized cancer medicine by key opinion leaders who presented at the Worldwide Innovative Networking (WIN) symposium (**).

So what is personalized medicine?

Personalized medicine is a huge movement in the modern medical world. It aims to move away from the traditional practice of prescribing standard doses of standard drugs for a condition to every patient, and shifts the focus onto targeting the precise drug and dose required according to the patient’s physiology.

This is achieved by detecting and tracking molecular biomarkers, which indicate the presence and level of activity of a particular biological system in a patient’s body, whether inherent or foreign.

Another major part of the emerging field of personalized medicine is pharmacogenomics – analyzing the genetic makeup of the patient to determine whether a particular medication will be successful, or if it will have any adverse effects. (1). This is particularly important in cancer treatment, where the chemotherapy drugs used can be very damaging to healthy cells as well as cancerous ones, and the exact genetics of the tumor cells can vary widely between patients, and even between locations in one patient’s body.

Personalized medicine involves:

  • Detection (DNA polymorphism, RNA and protein expression, metabolits, Lipids etc)
  • Diagnosis (imaging)
  • Prognosis and
  • Treatment (targeted-therapy)

Given the size symmetry, nanomaterials offer unprecedented sensitivity, capable of sensing  biological markers and processes at the single-molecule or  single-cell level either in vitro or in vivo.  Techniques are being developed for high-throughput DNA sequencing using nanopores, to obtain genetic information from a patient so that targeted medication can be selected as rapidly as possible.

Cancer, a very complex disease, is propagated by various types of molecular aberrations which drive the development and progression of malignancies. Large-scale screenings of multiple types of molecular aberrations (e.g., mutations, copy number variations, DNA methylations, gene expressions) become increasingly important in the prognosis and study of cancer. Consequently, a computational model integrating multiple types of information is essential for the analysis of the comprehensive data.

One of the greatest promises of near-term nanotechnoloogy is cheaper DNA sequencing to speed the development of personalized medicine. (3)

Nanotechnology and DNA sequencing

Tumors are known to be highly heterogenetic, due to the many acquired aberration in the cancer cells. Therefore,  there are not only genetic differences between different patients, but also genetic differences within the same patient; for example from different locations in the same patient, that can greatly affect the success of a therapy.  Therefore, sensitive and extensive yet inexpensive whole-genome sequencing is of major medical need to enable the application personalized medicine.  A review of the potential of this emerging nanotechnology “Nanopore sensors for nucleic acid analysis ” was published recently in Nature Nanotechnology (4).

The growing need for cheaper and faster genome sequencing has prompted the development of new technologies that surpass conventional Sanger chain-termination methods in terms of speed and cost.  These second- and third-generation sequencing  technologies — inspired by the $1,000 genome challenge proposed by the National Institutes of Health in 2004 (ref. 5) — are expected to revolutionize genomic medicine. Nanopore sensors are one of a number of DNA sequencing technologies that are currently poised to meet this challenge.

Nanopore Sequencing:

Nanopore-based sensing is attractive for DNA sequencing applications because it is a

  • label-free,
  • amplification-free,
  • single-molecule
  • requires low reagent volumes

approach that can be scaled for high-throughput DNA analysis.

This approach can be scaled up for high-throughput DNA analysis, it typically requires low reagent volumes, benefits from
relatively low cost and supports long read lengths, so it could potentially enable de novo sequencing and long-range haplotype mapping. Although, nanopore technology is not conceptually new and raised many skeptical opinions it has made major progress in the past few years and are thus worth sharing.

The principle of nanopore sensing is analogous to that of a Coulter counter. A nanoscale aperture (the nanopore) is formed in an insulating membrane separating two chambers filled with conductive electrolyte. Charged molecules (A,G,C,T) are driven through the pore under an applied electric potential (a process known as electrophoresis), thereby modulating the ionic current through the nanopore. This current reveals useful information about the structure and dynamic motion of the molecule.

Here’s an example for  a nanopore-based sequencing device is a Graphene- chip that is used as trans-electrode membrane (5).

An external file that holds a picture, illustration, etc.Object name is nihms-225875-f0001.jpg Object name is nihms-225875-f0001.jpg

Electrical measurements on graphene membranes in which a single nanopore has been drilled show that the membrane’s effective insulating thickness is less than one nanometer. This small effective thickness makes graphene an ideal substrate for very high-resolution, high throughput nanopore-based single molecule detectors. The sensitivity of graphene’s in-plane electronic conductivity to its immediate surface environment, as influenced by trans-electrode potential, will offer new insights into atomic surface processes and sensor development opportunities. (4-6).

A nanopore-based diagnostic tool could offer various advantages:

  • it could detect target molecules at very low concentrations from very small sample volumes;
  • it could simultaneously screen panels of biomarkers or genes (which is important in disease diagnosis,
  • monitoring progression and prognosis);
  • it could provide rapid analysis at relatively low cost; and
  • it could eliminate cumbersome amplification and conversion steps such as PCR, bisulphite conversion and Sanger sequencing

Nanopores are likely to have an increasing role in medical diagnostics and DNA sequencing in years to come, but they will face competition from a number of other techniques. These include

  • single-molecule evanescent field detection of sequencing-by-synthesis in arrays of nanochambers (Pacific Biosciences),
  • sequencing by ligation on self-assembled DNA nanoarrays (Complete Genomics), and the
  • detection of H+ ions released during sequencing-by-synthesis on silicon field-effect transistors from multiple polymerase-template reactions (Ion Torrent).

However, the possibility of using nanopore-based sensors to perform long base reads on unlabelled ssDNA molecules in a rapid and costeffective manner could revolutionize genomics and personalized medicine.

Current trends suggest that many challenges in sequencing with biological nanopores

  • the high translocation velocity and the
  • lack of nucleotide specificity

have been resolved. Similarly, given the progress with solid-state nanopores, if the

  • translocation velocity could be reduced to a single nucleotide (which is ~3Å long) per millisecond, and if
  • nucleotides could be identified uniquely with an electronic signature (an area of intense research),

it would be possible to sequence a molecule containing one million bases in less than 20 minutes. Furthermore, if this technology could be scaled to an array of 100,000 individually addressed nanopores operating in parallel, it would be possible to sequence an entire human genome (some three billion base pairs) with 50-fold coverage in less than one hour.

Although, none of the nanopore-solid base sequencing technique have been used as a tool in a clinical trial, one UK-based biotechnology company has its way, nanopore sequencing may soon be available to the public. Earlier this year 2012 Oxford Nanopore Technologies (ONT) announced that it was on the verge of manufacturing a commercial nanopore sensor. [The company said that by year’s end it would release a $900 handheld model, which it claims can sequence a virus genome 48 000 bases long, and a larger, scalable model that could decode a human genome in as little as 15 minutes. In contrast, conventional systems cost upward of $500 000 and take weeks to sequence a human genome (7).]

REFERENCES

** http://www.nature.com/nrclinonc/focus/personalized-medicine/index.html

1. http://www.azonano.com/article.aspx?ArticleID=3078

2. G.E. Marchant. Small is Beautiful: What Can Nanotechnology Do for Personalized Medicine?. Current Pharmacogenomics and Personalized Medicine, 2009, 7, 231-237http://www.benthamscience.com/cppm/Sample/cppm7-4/002AF.pdf

3. http://www.foresight.org/nanodot/?p=4992

4. Venkatesan BM and Bashi R. Nanopore sensors for nucleic acid analysis. Nature Nanotechnology 2011; 18: http://libna.mntl.illinois.edu/pdf/publications/127_venkatesan.pdf

5. Garaj S., Hubbard W., Reina A., King J., Branton D and Golovchenko JA. Graphene as a sub-nanometer trans-electrode membrane. Nature 2010 (9) 467(7312): 190-193. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2956266/

6. Min SK., Kim WY., Cho Y and Kim KS. Fast DNA sequencing with a graphene-based nanochannel device. Nature Nanotechnology 2011; 6: 162-165.  http://biophy.nju.edu.cn/lablog/wp-content/uploads/2011/10/Fast-DNA-sequencing-with-a-graphene-based.pdf

7. http://www.physicstoday.org/resource/1/phtoad/v65/i11/p29_s1?bypassSSO=1

Read Full Post »

Reporter: Larry H Bernstein, MD, FCAP

Big Data in Genomic Medicine

Image Source: Created by Noam Steiner Tomer 7/31/2020

Pathologists May Be Healthcare’s Rock Stars of Big Data in Genomic Medicine’s ’Third Wave’

Published: December 17 2012

Pathologists are positioned to be the primary interpreters of big data as genomic medicine further evolves

Pathologists and clinical laboratory managers may be surprised to learn that at least one data scientist has proclaimed pathologists the real big data rock stars of healthcare. The reason has to do with the shift in focus of genomic medicine from therapeutics and presymptomatic disease assessment to big data analytics.

In a recent posting published at Forbes.com, data scientist Jim Golden heralded the pronouncement of Harvard pathologist Mark S. Boguski, M.D., Ph.D., FACM. He declared that “The time of the $1,000 genome meme is over!”

DNA Sequencing Systems and the $1,000 Genome

Golden has designed, built, and programmed DNA sequencing devices. He apprenticed under the Human Genome program and spent 15 years working towards the $1,000 genome. “I’m a believer,” he blogged. “[That’s] why I was so intrigued [by Boguski’s remarks].

Boguski is Associate Professor of Pathology at the Center for Biomedical Informatics at Harvard Medical School and the Department of Pathology at Beth Israel Deaconess Medical Center. It was in a presentation at a healthcare conference in Boston that Boguski pronounced that it is time for the $1,000 genome to go.

“Big data analytics” will be required for translational medicine to succeed in the Third Wave of Genetic Medicine. That’s the opinion of Mark S. Boguski, M.D., Ph.D., who is a pathologist-informatist at Harvard Medical School and Beth Israel Deaconess Medical Center. Boguski predicts that pathologists are positioned to become the “rock stars” of big data analytics. For pathologists and clinical laboratory administrators, that means that big computer power will become increasingly important for all medical laboratories. (Photo by Medicine20Congress.com.)

Both Golden and Boguski acknowledged the benefits generated by the race to the $1,000 genome. Competition to be first to achieve this milestone motivated scientists and engineers to swiftly drive down the cost of decoding DNA. The result was a series of advances in instrumentation, chemistry, and biology.

Pathologists and Big Data Analytics

“Our notions about how genome science and technology would improve health and healthcare have changed,” Boguski wrote in an editorial published at Future Medicine. He then noted that the focus has shifted to big data analytics.

In the editorial, Boguski described the phases of development of genomic medicine as “waves.” The first wave occurred during the mid- to late-1990s. It focused on single- nucleotide polymorphisms (SNP) and therapeutics.

Medical Laboratories Have Opportunity to Perform Presymptomatic Testing

The second wave focused on presymptomatic testing for disease risk assessment and Genome Wide Association Studies (GWAS). Researchers expected this data to help manage common diseases.

The first two waves of medical genomics were conducted largely by the pharmaceutical industry, as well as with  primary care and public health communities, according to Boguski. Considerable optimism accompanied each wave of medical genomics.

“Despite the earlier optimism, progress in improving human health has been modest and incremental, rather than paradigm-shifting,” noted Boguski, who wrote that,to date, only a handful of genome-derived drugs have reached the market. He further observed that products such as direct-to-consumer genomic testing have proved more educational and recreational than medical.

“Third Wave” of Genomic Medicine

It was rapid declines in the cost of next-generation DNA sequencing technologies that now has triggered the third wave of genomic medicine. Its focus is postsymptomatic genotyping for individualized and optimized disease management.

“This is where genomics is likely to bring the most direct and sustained impact on healthcare for several reasons,” stated Boguski. “Genomics technologies enable disease diagnosis of sufficient precision to drive both cost-effective [patient] management and better patient outcomes. Thus, they are an essential part of the prescription for disruptive healthcare reform.”

Boguski reiterated the case for the value of laboratory medicine. He stated the following critical—but often overlooked—points, each of which is familiar to pathologists and clinical laboratory managers:

1. Pathologist-directed, licensed clinical laboratory testing has a major effect on clinical decision-making.

2. Medical laboratory testing services account for only about 2% of healthcare expenditures in the United States.

3. Medical laboratory services strongly influence the remaining 98% of costs through the information they provide on the prevention, diagnosis, treatment, and management of disease.

Molecular Diagnostics Reaching Maturity for Clinical Laboratory Testing

“Genome analytics are just another technology in the evolution of molecular diagnostics,” Boguski declared in his editorial.

Read more: Pathologists May Be Healthcare’s Rock Stars of Big Data in Genomic Medicine’s ’Third Wave’ | Dark Daily http://www.darkdaily.com/pathologists-may-be-healthcare%e2%80%99s-rock-stars-of-big-data-in-genomic-medicines-third-wave-1217#ixzz2FL24IRAA

English: Created by Abizar Lakdawalla.

English: Created by Abizar Lakdawalla. (Photo credit: Wikipedia)

English: Workflow for DNA nanoball sequencing

English: Workflow for DNA nanoball sequencing (Photo credit: Wikipedia)

DNA sequence

DNA sequence (Photo credit: Wikipedia)

Big Data: water wordscape

Big Data: water wordscape (Photo credit: Marius B)

Comment & Response

Right now the cost of the testing and the turnaround times are not favorable. It is going to take a decade or more for clinical labs to catch up. For some time it will be send out tests to Quest, LabCorp, and State or University lab consortia.

The power of the research technology is pushing this along, but for Personalized Medicine the testing should be coincident with the patient visit, and the best list of probable issues should be accessible on the report screen. The EHR industry is dominated by 2 companies that I see have no interest in meeting the needs of the physicians. The payback has to be on efficient workflow, accurate assessment of the record, and timely information. The focus for 25 years has been on billing structure. But even the revised billing codes (ICD10) can’t be less than 5 years out-of-date because of improvements in the knowledge base and improvements in applied math algorithms.

The medical record still may have information buried min a word heap, and the laboratory work is a go-to-you know where sheet with perhaps 15 variables on a page, with chemistry and hematology, immunology, blood bank, and microbiology on separate pages. The ability of the physician to fully digest the information with “errorless” discrimination is tested, and the stress imposed by the time for each patient compromises performance. There is work going on in moving proteomics along to a high throughput system for improved commercial viability, that was reported by Leigh Anderson a few years ago. The genomics is more difficult, but the genomics is partly moving to rapid micropanel tools.

In summary, there are 3 factors:

1. Automation and interpretation
2. Integration into the EHR in real time and usable by a physician.
3. The sorting out of the highest feature “predictors” and classifying them into clinically meaningful sets and subsets.

When this is done, then the next generation of recoding will be in demand.
The Automated Malnutrition Assessment
Gil David1, Larry Bernstein2, Ronald R. Coifman1

1Department of Mathematics, Program in Applied Mathematics,
Yale University, New Haven, CT 06510, USA,
2Triplex Consulting, Trumbull, CT 06611

Abstract

Introduction: We propose an automated nutritional assessment (ANA) algorithm that provides a method for malnutrition risk prediction with high accuracy and reliability.

Materials and Methods: The database used for this study is a file of 432 patients, where each patient is described by 4 laboratory parameters and 11 clinical parameters. A malnutrition risk assessment of low (1), moderate (2) or high (3) was assigned by a dietitian for each patient. An algorithm for data organization and classification via characteristic metrics is proposed. For each patient, the algorithm characterizes its unique profile and builds a characteristic metric to identify similar patients who are mapped into a classification.

Results: The algorithm assigned a malnutrition risk level for each patient based on different training sizes that were taken out of the data.

Our method resulted in an average error (distance between the automated score and the real score) of 0.386, 0.3507, 0.3454, 0.34 and 0.2907 for 10%, 30%, 50%, 70% and 90% training sizes, respectively.

Our method outperformed the compared method even when our method used a smaller training set then the compared method. In addition, we show that the laboratory parameters themselves are sufficient for the automated risk prediction and organize the patients into clusters that correspond to low, low-moderate, moderate, moderate-high and high risk areas.

Discussion: The problem of rapidly identifying risk and severity of malnutrition is crucial for minimizing medical and surgical complications. These are not easily performed or adequately expedited. We characterize for each patient a unique profile and map similar patients into a classification. We also find that the laboratory parameters themselves are sufficient for the automated risk prediction.

Keywords: Network Algorithm, unsupervised classification, malnutrition screening, protein energy malnutrition (PEM), malnutrition risk, characteristic metric, characteristic profile, data characterization, non-linear differential diagnosis.

Read Full Post »

 

Reporter: Aviva Lev-Ari, PhD, RN

J Cardiovasc Transl Res. 2012 Sep 7. [Epub ahead of print]

Next Generation Diagnostics in Inherited Arrhythmia Syndromes : A Comparison of Two Approaches.

Ware JSJohn SRoberts AMBuchan RGong SPeters NSRobinson DOLucassen ABehr ERCook SA.

Source

MRC Clinical Sciences Centre, Imperial College London, London, UK, j.ware@imperial.ac.uk.

Abstract

Next-generation sequencing (NGS) provides an unprecedented opportunity to assess genetic variation underlying human disease. Here, we compared two NGS approaches for diagnostic sequencing in inherited arrhythmia syndromes. We compared PCR-based target enrichment and long-read sequencing (PCR-LR) with in-solution hybridization-based enrichment and short-read sequencing (Hyb-SR). The PCR-LR assay comprehensively assessed five long-QT genes routinely sequenced in diagnostic laboratories and “hot spots” in RYR2. The Hyb-SR assay targeted 49 genes, including those in the PCR-LR assay. The sensitivity for detection of control variants did not differ between approaches. In both assays, the major limitation was upstream target capture, particular in regions of extreme GC content. These initial experiences with NGS cardiovascular diagnostics achieved up to 89 % sensitivity at a fraction of current costs. In the next iteration of these assays we anticipate sensitivity above 97 % for all LQT genes. NGS assays will soon replace conventional sequencing for LQT diagnostics and molecular pathology.

PMID: 22956155 [PubMed]
Source: 
http://www.ncbi.nlm.nih.gov/pubmed/22956155

Researchers in the UK have compared a PCR-based and a capture hybridization-based assay for sequencing panels of inherited cardiovascular disease genes and have found both to be suitable for diagnostics in principle, though their sensitivity needs to be optimized.

According to James Ware, a clinical lecturer at Imperial College London, the purpose of the study, published online this month in the Journal of Cardiovascular Translational Research, was to evaluate different approaches for sequencing cardiovascular disease genes, both for molecular diagnosis and for large-scale resequencing research studies.

His group, in the National Institute for Health Research Royal Brompton Cardiovascular Biomedical Research Unit, is interested in a range of inherited heart disease types, including cardiomyopathies and inherited arrhythmia syndromes such as long QT syndrome.

For their study, they compared two next-gen sequencing assays: a PCR-based approach that uses Fluidigm’s Access Array to amplify 96 amplicons in five LQT genes and one other gene, followed by sequencing on the 454 GS Junior; and an in-solution hybridization approach that uses Agilent’s SureSelect to target 49 inherited arrhythmia genes and sequences them on Life Technologies’ SOLiD 4.

The study focused on the sensitivity of the assays, or how well they were able to capture their intended targets, rather than their specificity, or their ability to avoid false positives.

Ware said that at the time of the study, PCR and in-solution capture were the two main target selection methods available. The researchers are still using both approaches but are now employing “a wide range of sequencers” from various providers for both types of assays, including Illumina instruments and Life Tech’s Ion Torrent.

For their comparison, they analyzed 48 samples, of which they sequenced 33 with both approaches and 15 using either one or the other.

The samples included 19 known variants in three disease genes, of which the hybridization-SOLiD method detected 17 and the PCR-454 method 14. Undetected variants were generally in areas that were not well covered, either due to a failure in enrichment, sequencing, or because the alignment was not unique. One variant that was missed by both approaches fell in a very GC-rich region.

Consumables costs for both assays were considerably lower than with Sanger sequencing: While sequencing five genes by Sanger costs more than $700 in consumables, the five-gene PCR/454 assay cost about $55 and the 49-gene hybridization/SOLiD assay cost about $200, according to the study.

Turnaround time is the shortest for Sanger sequencing, which, according to the study, can be done in one day for five genes and 17 samples, not including sample prep. The PCR/454 assay takes about two days for target enrichment and sequencing 48 samples, and the hybridization/SOLiD assay takes about two weeks for sequencing alone, they wrote.

Overall, Ware said, both sequencing approaches performed “reasonably well” and are significantly cheaper than Sanger sequencing. He said that in the UK, molecular diagnosis for inherited cardiovascular disease has traditionally been performed by Sanger, at a cost of approximately £500 to £1,000 ($800 to $1,600) for several genes involved in a clinical condition. However, for cost reasons, not all relevant genes are usually sequenced.

Target selection was the performance-limiting step for both approaches, a result the researchers expected. “It sounds obvious, but not all genes are equally easy to target,” Ware said. For example, in the hybridization assay, the overall target coverage was about 98 percent, but for some genes, it was only 80 percent or 90 percent. The two most important genes in long QT syndrome, KCNQ1 and KCNH2, “proved to be the hardest to sequence.”

Thus, for diagnostic use of NGS gene panels, “it’s important to know not just how the system performs overall but really how it’s performing for the specific genes you’re interested in,” he said.

To use either approach in diagnostics, the target selection step would need to be optimized. Ware’s team has already improved both assays and is now trying them in a number of fully Sanger-sequenced samples to study both sensitivity and specificity.

Longer term, the sensitivity of next-gen sequencing could approach that of Sanger sequencing, he said. And even if it does not reach 100 percent, because NGS approaches can target so many more genes, “maybe you can afford a very slight tradeoff in the per-gene sensitivity if the overall diagnostic sensitivity of the panel goes up,” he said. “At the moment, because we don’t have that much experience in sequencing the less-common genes, we don’t exactly know where that tradeoff lies.” In addition, any gaps could be filled by Sanger sequencing, while the test would probably still be cost effective.

Each approach also has some features that make it more suitable for certain applications. The PCR-based method has a fast turnaround and an “extremely user-friendly workflow,” Ware said, but it can only accommodate a small number of genes at the moment. His team also found it to be easier to optimize and improve. Thus, in the short term, PCR and sequencing “is probably closer to providing a diagnostic solution,” he said, especially for conditions where only a few genes are causative.

The hybridization-based approach, on the other hand, has much greater capacity, and there are advantages in “having a single assay that covers everything,” he said. It might also be possible to detect copy number variants using this approach, but not the more limited PCR method, he added.

Ware and his colleagues are currently using the hybridization approach to study a large panel of genes in 2,000 well-phenotyped volunteers, both healthy individuals and heart disease patients.

They have also started to use the hybridization method to sequence the TTN gene, truncating mutations in which were recently found to be a common cause of dilated cardiomyopathy. They are running the TTN test routinely for patients consented for research diagnostic testing that is not available anywhere else. Because this gene is so large, it is “completely impractical to be sequenced by conventional Sanger,” Ware said.

Julia Karow tracks trends in next-generation sequencing for research and clinical applications for GenomeWeb’s In Sequenceand Clinical Sequencing News. E-mail her here or follow her GenomeWeb Twitter accounts at @InSequence and@ClinSeqNews.

 

Read Full Post »

Curator: Aviva Lev-Ari, PhD, RN

Sunitinib brings Adult acute lymphoblastic leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade

http://pharmaceuticalintelligence.com/2012/07/09/sunitinib-brings-adult-all-to-remission-rna-sequencing/

 

Read Full Post »

Curator: Aviva Lev-Ari, PhD, RN

Sunitinib brings Adult acute lymphoblastic leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade

Screen Shot 2021-07-19 at 7.36.02 PM

Word Cloud By Danielle Smolyar

http://pharmaceuticalintelligence.com/2012/07/09/sunitinib-brings-adult-all-to-remission-rna-sequencing/

 

Read Full Post »

Curator: Aviva Lev-Ari, PhD, RN

Sunitinib brings Adult acute lymphoblastic leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade

http://pharmaceuticalintelligence.com/2012/07/09/sunitinib-brings-adult-all-to-remission-rna-sequencing/

 

Read Full Post »

Sunitinib brings Adult Acute Lymphoblastic Leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade

Curator: Aviva Lev-Ari, PhD, RN

Article ID #1: Sunitinib brings Adult Acute Lymphoblastic Leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade. Published on 7/9/2012

WordCloud Image Produced by Adam Tubman

Sunitinib brings Adult Acute Lymphoblastic Leukemia (ALL) to Remission – RNA Sequencing – FLT3 Receptor Blockade

Word Cloud by Daniel Menzin

Updated 11/13/2013

Pazopanib versus Sunitinib in Renal Cancer

N Engl J Med 2013; 369:1968-1970November 14, 2013DOI: 10.1056/NEJMc1311795

Article

To the Editor:

Cancer treatments are expensive. The estimation of the total cost can be challenging because of several factors such as efficacy, toxicity, and the costs and duration of supportive care and end-of-life care. Motzer et al. (Aug. 22 issue)1 report similar efficacy but a favorable safety and quality-of-life profile and less medical resource utilization with pazopanib as compared with sunitinib in first-line therapy for metastatic renal cancer. Since oncology is becoming an increasingly value-based specialty, we wanted to highlight another important aspect of this trial. Pazopanib appears to be favorable not only in terms of safety and quality of life, but also in terms of overall cost. A 30-day supply of pazopanib (at a dose of 800 mg daily) ranges from $3,500 to $8,556, whereas a 30-day supply of sunitinib (at a dose of 50 mg daily) ranges from $4,500 to $13,559.2 The total cost of pazopanib during the median progression-free survival of 8.4 months is $29,400 to $71,870, and the total cost of sunitinib during the median progression-free survival of 9.5 months is $42,750 to $127,454. Less toxicity and less medical resource utilization with pazopanib will most likely further lower the overall costs of treatment with this agent. Comparative-effectiveness trials hold great promise for maximizing patient safety, improving treatment outcomes, and reducing costs.

Ryan Ramaekers, M.D.
Mark Tharnish, Pharm.D.
M. Sitki Copur, M.D.
Saint Francis Cancer Treatment Center, Grand Island, NE
mcopur@sfmc-gi.org

No potential conflict of interest relevant to this letter was reported.

2 References

To the Editor:

Motzer et al. report a combined analysis of two open-label noninferiority trials (927 patients in the original trial and 183 patients in a second trial), each of which compared pazopanib with sunitinib with respect to progression-free survival in renal-cell carcinoma. Quality-of-life outcomes were subjective.

Analysis of noninferiority trials is notoriously difficult.1,2 The authors’ analysis of the trials, which was open-label because of the different administration schedules of the drugs, presents problems in interpreting progression-free survival and quality of life. The studies define disease progression differently. The larger study defined progression-free survival according to independent review. The protocol for the smaller study states that progression-free survival “will be summarized . . . based on the investigator assessment.” Inference from subjective outcomes in unmasked trials (e.g., quality of life in both studies and progression-free survival in the smaller study and therefore in the combined analysis) is subject to well-known bias. Moreover, the article does not state how many of the 379 participants (34%) who discontinued the intervention before death or disease progression (see Fig. S2 in the Supplementary Appendix, available with the full text of the article at NEJM.org) were assessed for progression-free survival. A fair comparison must use rigorous methods to handle missing data.3 Since the article did not deal appropriately with missing data, its conclusions regarding noninferiority are uninterpretable.

Janet Wittes, Ph.D.
Statistics Collaborative, Washington, DC
janet@statcollab.com

Dr. Wittes reports that her company, Statistics Collaborative, has consulting agreements with both GlaxoSmithKline and Pfizer, the manufacturers of the drugs discussed in the article by Motzer et al. In addition, Statistics Collaborative has contracts with several other companies that produce drugs for patients with cancer. No other potential conflict of interest relevant to this letter was reported.

3 References

To the Editor:

Motzer et al. state that “the results of the progression-free survival analysis in the per-protocol population were consistent with the results of the primary analysis.” However, the predefined margin of noninferiority (<1.25) was not met. The upper limit of the confidence interval (1.255) was clearly above the defined threshold.1 In a noninferiority trial, the use of the intention-to-treat population is generally nonconservative,2 the full analysis set and the per-protocol analysis set are considered to have equal importance, and the use of the intention-to-treat population should lead to similar conclusions for a robust interpretation.3 Thus, it is surprising that the authors did not come to or discuss the same conclusions as that of the French National Authority for Health4: “serious doubt exists about the noninferiority result of pazopanib compared to sunitinib” and “the clinical significance of the noninferiority threshold defined in the protocol was an efficacy loss of 2.2 months in the median progression-free survival. This is too large for patients.”

Jochen Casper, M.D.
Silke Schumann-Binarsch, M.D.
Claus-Henning Köhne, M.D.
Klinikum Oldenburg, Oldenburg, Germany
casper.jochen@klinikum-oldenburg.de

Dr. Casper reports receiving consulting fees from Bayer, Novartis, and Pfizer and speaking fees from Novartis and Pfizer. No other potential conflict of interest relevant to this letter was reported.

4 References

The authors reply: In reply to Ramaekers et al.: we agree that decisions regarding the provision of health care include economic evaluations to identify treatments that provide the best clinical benefit at an acceptable cost.

To clarify a point in the letter by Wittes: the primary end point of this phase 3 trial was progression-free survival evaluated by an independent review committee; these data were assessed for all 1110 patients from both trials. This is specified in the protocol. The consistency of the quality-of-life results with the observed differences in the safety profiles for the two drugs speaks to the absence of bias in the quality-of-life outcome. The number of patients in whom follow-up ended before progression was assessed by the independent review committee was balanced between the two groups: 156 patients in the pazopanib group (28%) and 168 patients in the sunitinib group (30%). To Wittes’s final point regarding rigorous methods to handle missing data: the algorithm for assigning disease-progression and censoring dates followed the Guidance for Industry of the Food and Drug Administration1 and is included in the protocol of our article.

In reply to Casper et al.: there is no consensus regarding whether the per-protocol population is more conservative than the intention-to-treat population for the noninferiority analysis.2,3Reviews of noninferiority trials indicate that the per-protocol population is not generally more conservative than the intention-to-treat population, and there are scenarios in which the per-protocol analysis itself could introduce bias.3 A systematic review indicated that more than 70% of published findings from noninferiority trials in oncology show results in only the intention-to-treat population and not in the per-protocol population.4 Our phase 3 trial had a single primary analysis in the intention-to-treat population, with the per-protocol population included as a key sensitivity analysis, as supported by Fleming et al.5 No formal hypothesis testing was planned for the per-protocol population, nor was the trial powered for this. Consistency of the point estimates was desired to show an absence of bias due to the analysis population. This absence of bias was shown by the consistency of the hazard ratios (1.07 in the per-protocol analysis vs. 1.05 in the primary analysis). For an underpowered per-protocol comparison, it is inappropriate for Casper et al. to interpret that the upper bound that barely exceeded 1.25 in our per-protocol analysis is an indication of inconsistency of results across the two populations. The noninferiority margin was selected in consultation with oncology experts, and justification of the margin is in the protocol.

Robert J. Motzer, M.D.
Memorial Sloan-Kettering Cancer Center, New York, NY
motzerr@mskcc.org

Lauren McCann, Ph.D.
Keith Deen, M.S.
GlaxoSmithKline, Collegeville, PA

Since publication of their article, the authors report no further potential conflict of interest.

REFERENCES

Food and Drug Administration. Guidance for industry: clinical trial endpoints for the approval of cancer drugs and biologics. May 2007 (http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm071590.pdf).
Jones B, Jarvis P, Lewis JA, Ebbutt AF. Trials to assess equivalence: the importance of rigorous methods. BMJ 1996;313:36-39[Erratum, BMJ 1996;313:550.]
CrossRef | Web of Science | Medline
Brittain E, Lin D. A comparison of intent-to-treat and per-protocol results in antibiotic non-inferiority trials. Stat Med 2005;24:1-10
CrossRef | Web of Science | Medline
Tanaka S, Kinjo Y, Kataoka Y, Yoshimura K, Termukai S. Statistical issues and recommendations for noninferiority trials in oncology: a systematic review. Clin Cancer Res 2012;18:1837-1847
CrossRef | Web of Science | Medline
Fleming TR, Odem-Davis K, Rothmann MD, Li Shen Y. Some essential considerations in the design and conduct of non-inferiority trials. Clin Trials2011;8:432-439
CrossRef | Web of Science | Medline
SOURCE

Original Article Published on 7/9/2012

July 6, 2012 NY Times reports on a new approach based on DNA and RNA sequencing and a cancer drug for kidney cancer to bring REMISSION to Adult acute lymphoblastic leukemia (ALL).

On the lower left corner of this page – Watch the VIDEO

second-chance.html

Dr. Lukas Wartman, is a Cancer Researcher specializing in Leukemia. He suspected he had Leukemia, the very disease he had devoted his medical career to studying.

After years of treatment and two relapses of ALL, he has exhaused all conventional approaches to his disease. At Washington University in St. Louis, his colleagues in the lab, decoded Dr. Wartman’s genetic information by genome sequencing techniques t determine the genetic cause of his ALL. The team found an overactive gne, FLT3 on Chromosome 13. The gene was treated with pfizer’s Suntinib drug for advanced kidney cancer.

Blood samples free of ALL found in days after using the drug. As results were very promising, Pfizer, the drug’s maker who has turned down Dr. Wartman’s request for the drug under their compassionate use program, though he explained that his entire salary was only enough to pay for 7 1/2 months of Sutent (Suntinib). While he does not know why Pfizer gave him the drug finally, he suspects it was the plea of his Nurse Practitioner, Stephanie Bauer, NP.

Identification of the genetic cause for his ALL, thus discovering a breakthough in understanding and treatment for ALL in other patients, involved the following steps:

SAMPLE

two tissue samples taken from Dr. Wartman’s Bone marrow and skin cells

SEQUENCE

Extracts of DNA and RNA from Dr. Wartman’s cells, two types of genetic material tested

COMPARISON

DNA sequesnces showed genetic mutations possibly related to his ALL, none seemed treatable. However, RNA sequencing revealed that a normal Gene, FLT3, on cheomozome 13, was overactive in his leukemia cells

TARGETING

The FLT3 gene helps create new white blod cells in the bone marrow. Dr. Wartman’s marrow bone cells were covered with an extreme number of FLT3 receptors which possibly caused the growth of his leukemia.

TREATMENT – Receptor Blockade 

Drug known to block FLT3 receptor, Sunitinib, used for kedney cancer treatment, was given to Dr. Wartman. Two weeks after Dr, Wartman began taking the drug, tests revealed that his leukenia was in remission.

NEW MARKETS FOR FLT3  GENE BLOCKADE DRUG  – KIDNEY CANCER AND LEUKEMIA

Pfizer has NOW a NEW market for Sunitinib — All CANCER PATIENTS DIAGNOSED WITH Adult acute lymphoblastic leukemia (ALL) where an overactive FLT3 gene on chomosome 13 is found.

NEW TREATMENT OPTIONS FOR Adult acute lymphoblastic leukemia (ALL)

Thus, any (ALL) diagnosed patient needs to be tested for Chromosome 13, ONLY rather then the entire genome sequencing of the Patient. If FLT3 is not found overactive, THEN proceed with entire genome sequencing of the Patient. IF another gene is overactive FIND DRUG FOR RECEPTOR BLOCKADE.

SIZING THE MARKET FOR FLT3 BLOCKADE DRUGS: KIDNEY CANCER vs LEUKEMIA

The Market for Adult ALL is much bigger than the market for kidney cancer. Thus, this discovery regarding the remission of Dr. Wartman’s remission following two relapses is so significant for Pfizer and for any patient with the diagnosis of Adult ALL.

I recommend the reader to click on the links and follow the reactions of the public to this article in The New York Times.

http://www.nytimes.com/2012/07/08/health/in-gene-sequencing-treatment-for-leukemia-glimpses-of-the-future.html?pagewanted=all

Read HUNDREDS of Comments by Cancer Patients and the readers of The New York Times Health Section

http://www.nytimes.com/2012/07/08/health/in-gene-sequencing-treatment-for-leukemia-glimpses-of-the-future.html?pagewanted=all#commentsContainer

Read Full Post »

« Newer Posts