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PTC124, a Drug Against Genetic Diseases: Overview

I’ve already written about the Times Online article (Daily pill to beat genetic diseases), but I would like to give a clear overview of this “miracle-drug”. The story of PTC124 is not new, it goes back to 2004. Anyway, what is it about?

PTC124 is a novel, orally administered small-molecule compound that targets a particular genetic alteration known as a nonsense mutation. Genetic disorders occur as a consequence of mutations in an individual’s DNA. Nonsense mutations are alterations in the DNA that, when transcribed into mRNA, introduce a premature translation termination codon. This change halts the ribosomal translation process at an earlier site than normal, producing a truncated, non-functional protein.

ptc.jpg

So PTC124 binds to the ribosome, ignores the nonsense mutation, but doesn’t repair it and make the genetic disease “go away” as it makes it possible for the body to produce the proper protein. Just some examples for genetic diseases caused by nonsense mutation (of the approximately 1800 similar diseases):

As it doesn’t repair the mutation, patients have to take the pill throughout their lives. Here is an image, how it works exactly:

ptc_technology.jpg

OK, it sounds fantastic, but what about the studies?

You can read more about the phase 2 clinical trials of Duchenne muscular dystrophy and cystic fibrosis as well. The description of phase 2 clinical trials for Duchenne muscular dystrophy says:

The results from this study indicate that PTC124 is well-tolerated and imply pharmacological activity based on preliminary data that suggest increases in dystrophin in muscle biopsies in a number of patients and statistically significant improvements in creatine kinase in blood… several parents and teachers have reported that boys participating in the study have had improvements in terms of greater activity and increased endurance during treatment.


Phase 2 clinical trials for Cystic Fibrosis:

Across the two studies, at both PTC124 dose levels tested, TEPD assessments showed statistically significant improvements of average CFTR-dependent chloride secretion in the airwaysAlthough a formal symptom assessment was not a component of the Phase 2 program, a number of patients described decreased sputum volume and thickness, decreased frequency and severity of coughing and a better sense of well-being during PTC124 therapy.

I have to admit that these results are incredible, look how dystrophin was rebuilt:

dystrophin.jpg

It also sounds great, though I think we should be a little skeptic as new therapies are always presented as miracle methods in spite of side effects and non-expected mistakes. Anyway, it might be a really exceptional improvement in the future. I’m eagerly waiting for the results of the next clinical trials. Until then, in case you’re still interested, read more about PTC124:

Related links:

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32 Comments Post a comment
  1. What a great post. How come I never bumped into this great blog before. If you ever need any advice re: specialty or anything else send me a line.

    -Steve
    http://www.thegenesherpa.blogspot.com

    May 5, 2007
  2. You see,
    the first thing to go is your short term memory. Of course…..
    Remember, write everything down :)
    Everything
    -Steve
    http://www.thegenesherpa.blogspot.com

    May 5, 2007
  3. Thank you for the kind words, Steven! You do the greatest blog on the subject, so I have a lot of things to learn from you…

    And if you need a new collaborator who is a medical blogger and plans to spend his lifetime specializing in clinical genetics, send me a line. :)

    May 5, 2007
  4. sparc #

    To my best kowledge to overcome PTC induced NMD another amino acid has to be introduced in the growing peptide chain via a suppressor t-RNA. Thus, I wonder which amino acid was introduced in the described cases and if PTC124 will work with every PTC in every gene. Or will treatment of other PTCs result in a full length abeit non-functional proteins?

    May 7, 2007
  5. It’s interesting what you’re saying. Do you happen to know any kind of publications on the field?

    May 7, 2007
  6. K.K.Sharma #

    I like to know if ptc124 will be suitable for post polio syndrums( PPS). That also damage muscles. Although mechanism is diffrent and PPS patients have very high level of CK in their blood. That can be said it is nerve related but end results are same. If any body have full knowledge of PTC124 working and are there any trials going on relative to polio effected patients.

    May 31, 2007
  7. Kathryn Wright #

    PTC124 will only work on inherited diseases caused by a premature stop codon mutation in a gene. All genes have stop codons at the end, but the “premature stop codon” is a mutation which happens too early in the gene. Due to this mutation, the protein you need isn’t made or is too short.

    PTC124 will not work on muscles or other parts of the body which are damaged by an infection like polio or by any other kind of physical damage – like an car accident.

    PTC124 will ONLY help people who have a premature stop codon mutation, not any other kind of mutation.

    September 25, 2007
  8. David Hagert #

    Will PTC-124 work on all nonsense mutations in mRNA? Like with all the stop codons UAA,UAG,UGA. Or just one type like the UAG?

    April 23, 2008
    • Feng Feng #

      However, it is not equally effective with every stop codon, working best on the sequence ‘UGA’ [1] – PTC124 WIKI

      October 7, 2009
  9. It seems it would work with all nonsense mutations.

    April 24, 2008
  10. K.K.Sharma #

    Kythryn Wright.
    Thanks for the info about PTC124. After long search and talking to several well known neurologists/proffessors. It is clear this medicine is not for polio or PPS. My friends have wasted large sum of money on stem cells if anybody have any info let us know or had any body any beneficial effects.

    August 25, 2008
  11. Abdoul Hossein Niksirat #

    dear sir ,
    Please give further information about the medicin PTC124 (inclding
    price and how to buy from my country Iran)
    Thanking you in anticipation of your kind attention.
    Yours faithfully
    Abdoul hossein Niksirat

    February 9, 2009
  12. Hi friens,

    upcourse ptc124 is available in U.SA and in U.K . I too dontknow howto get these medicines. Its very beneficial for all type of muscular dystrophy.

    Yours faithfully
    MAHESH

    March 3, 2009
  13. Hi This message for All Indian peoples who are all suffering from muscular dystrophy(different types).

    dear friends here a hppy news that the scientists discovered the medicine ptc 124 . still the clinical trials are going on. Eventhough these pills are avaailable in USA and UK. So why cant it is not possible to get in India. Plese try to publish the matter in Daily news papers.

    With hope,
    Mahesh

    March 3, 2009
  14. hi ptc 124 clinical trials finished. it may come 2 market wth a week.

    March 12, 2009
    • Feng Feng #

      PTC124 is scheduled to enter the final phase2b of clinical trials in 2009.

      Please see the link below for the clinical trials.

      http://www.clinicaltrials.gov

      October 7, 2009
  15. Hans Lindh #

    Does PTC 124 have effect on X-linked spondyloepiphyseal dysplasia tarda? I understand that it can be nonsense mutations involved i that Genetic Disease as well.

    December 9, 2009
  16. shashankgupta225 #

    Symptoms & Characteristics
    X-linked spondyloepiphyseal dysplasia tarda is a genetic condition that impairs bone growth and occurs almost exclusively in males. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends (epiphyses) of long bones in the arms and legs. “Tarda” indicates that signs and symptoms of this condition are not present at birth, but appear later in childhood, typically between ages 6 and 10.

    Males with X-linked spondyloepiphyseal dysplasia tarda have skeletal abnormalities and short stature. Affected boys grow steadily until late childhood, when their growth slows. Male adult height ranges from 4 feet 10 inches to 5 feet 6 inches. Individuals with X-linked spondyloepiphyseal dysplasia tarda have a short trunk and neck, and their arms appear disproportionately long. Impaired growth of the spinal bones (vertebrae) causes the short stature seen in this disorder. The spinal abnormalities include flattened vertebrae (platyspondyly) with hump-shaped bulges, progressive thinning of the discs between vertebrae, and an abnormal curvature of the spine (scoliosis or kyphosis). Other skeletal features of X-linked spondyloepiphyseal dysplasia tarda include an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); a broad, barrel-shaped chest; and decreased mobility of the elbow and hip joints. Arthritis often develops in early adulthood, typically affecting the hip joints and spine.

    January 1, 2010
  17. JYOTIRMAI BARTARIA #

    i want to know ptc124 when come in market and who and where i get it my 7 year old child suffering dmd

    January 4, 2010
    • Feng Feng #

      The pivotal trial of ataluren (formerly known as PTC124 ) in Duchenne’s muscular dystrophy has been completed and top-line pivotal data are expected in the first half 2010. If the data are positive, PTC could be on track to file a new drug application for ataluren in mid-2010 and potential accelerated approval in the first half of 2011. [Reference: http://www.bioworld.com/servlet/com.accumedia.web.Dispatcher?next=bioWorldHeadlines_article&forceid=53098%5D

      A specific type of mutation, called a nonsense (premature stop codon) mutation is the cause of DMD/BMD in approximately 10-15% of boys with the disease. Ataluren (PTC124) is an orally delivered, investigational drug that has the potential to overcome the effects of the nonsense mutation.

      January 5, 2010
  18. Anonymous #

    What is this suppose to do for kids with Hurler Syndrome? What about if they have been transplanted or not?

    January 5, 2010
  19. Here is a link to more information about the genetics of X-Linked Spondyloepiphyseal Dysplasia Tarda that was prepared by our genetic counselor and which has links to some useful resource for those dealing with this condition: http://www.accessdna.com/condition/_X-Linked_Spondyloepiphyseal_Dysplasia_Tarda/677. I hope it helps.  AccessDNA

    January 17, 2010
  20. Nice post. scienceroll.com deserves an oscar.

    March 10, 2010
  21. jack #

    I’m Iranian. duchenne one of my relatives has the disease. In our country for this disease is no treatment. But as far as I saw the Americans found the drug for this disease. I request that you support our oppressed people And poor in this country do not let our beloved bloodthirsty go of my hand.

    March 10, 2010
  22. SUDHAKARA REDDY.G #

    Respected Sir,
    My son (Master G.Venu Gopal Reddy ) has been suffering from Duchene Muscular Destrophy It has no treatment .But I felt very happy When I saw your blug. I would like to know the some information such as 1) How long does it take to come to the patients ?
    Thank u sir
    Yours truely,
    G.SUDHAKARA REDDY School Teacher
    H.No : 21/ 40 f Balakonda hall street
    Nandyal ( Town ) Andhra Pradesh ( State ) India

    March 19, 2010
  23. N.Gandhi Prasad #

    i want ur medicine PTC124 because i am suffering from MD from last 6 years

    August 27, 2011
  24. N.Gandhi Prasad #

    hi when ptc 124 medicine is available in the market can tell me about it. dis my mail id: gandhi.mca02@gmail.com
    pls tell i am suffering MD from 6years so kindly tell me information about PTC124

    September 1, 2011
  25. r #

    When ptc124 medicine come in market?

    May 27, 2012
  26. Hawas #

    hawas..
    Please…
    there is anyone know some news about ptc124 medicine , my relative suffering from DMD.
    My regards..
    KSA

    October 4, 2012

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  1. Gene Genie: a Famous Blog Carnival's Sixth Issue « ScienceRoll
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