Thursday, 25 September 2014

Making Sense of Genetic Manipulation in humans results of Oligonucleotide trials

Limmroth V, Barkhof F, Desem N, Diamond MP, Tachas G; For the ATL1102 Study Group. CD49d antisense drug ATL1102 reduces disease activity in patients with relapsing-remitting MS.
Neurology. 2014 Sep. pii: 10.1212/WNL.0000000000000926. [Epub ahead of print]

OBJECTIVE: This study evaluated the efficacy and safety of ATL1102, an antisense oligonucleotide that selectively targets the RNA for human CD49d, the α subunit of very late antigen 4, in patients with relapsing-remitting multiple sclerosis (RRMS).
METHODS: In a multicenter, double-blind, placebo-controlled randomized phase II trial, 77 patients with RRMS were treated with 200 mg of ATL1102 subcutaneously injected 3 times in the first week and twice weekly for 7 weeks or placebo and monitored for a further 8 weeks. MRI scans were taken at baseline and weeks 4, 8, 12, and 16. The primary endpoint was the cumulative number of new active lesions (either new gadolinium-enhancing T1 lesions or nonenhancing new or enlarging T2 lesions) at weeks 4, 8, and 12.
RESULTS: A total of 72 patients completed the study and 74 intention-to-treat patients were assessed. ATL1102 significantly reduced the cumulative number of new active lesions by 54.4% compared to placebo (mean 3.0 [SD 6.12] vs 6.2 [9.89], p = 0.01). The cumulative number of new gadolinium-enhancing T1 lesions was reduced by 67.9% compared to placebo (p = 0.002). Treatment-emergent adverse events included mild to moderate injection site erythema and decrease in platelet counts that returned to within the normal range after dosing.
CONCLUSIONS: In patients with RRMS, ATL1102 significantly reduced disease activity after 8 weeks of treatment and was generally well-tolerated. This trial provides evidence for the first time that antisense oligonucleotides may be used as a therapeutic approach in neuroimmunologic disorders.

We all know that tysabri which blocks CD49d can inhibit lesion formation and the development of relapse. This is given once a month and blocks MRI lesions by about 90% and relapse rate by about 70% compared to placebo. This study looks at another way to block CD49d and uses antisense DNA

DNA is made of the doublehelix of nucleotides. A a single strand of DNA sense (or positive (+) ) if an RNA version of the same sequence is translated or translatable into protein. Its complementary strand is called antisense (or negative (-) sense).

The two complementary strands of double-stranded DNA (dsDNA) are usually differentiated as the "sense" strand and the "antisense" strand. The DNA sense strand looks like the messenger RNA (mRNA) and can be used to read the expected protein code (e.g. ATG codon = Methionine amino acid). However, the DNA sense strand itself is not used to make protein by the cell. It is the DNA antisense strand which serves as the source for the protein code, because, with bases complementary to the DNA sense strand, it is used as a template for the mRNA. Since transcription results in an RNA product complementary to the DNA template strand, the mRNA is complementary to the DNA antisense strand. The mRNA is what is used for translation (protein synthesis).

The DNA sense strand is called a "sense" strand not because it will be used to make protein (it won't be), but because it has a sequence that looks like the protein codon sequence. In biology and research, short antisense molecules can interact with complementary strands of nucleic acids, modifying expression of genes.

In this case the anti-sense nucleotide interacts with CD49d and so the CD49d protein does not get made and this results in no CD49d protein and so the cells cannot migrate into the CNS.

Whilst this interesting we are taking a one a month drug and converting it to a twice a week drug, which is not quite as active as the monoclonal antibody it seeks to replace. Will it have the side effect of PML....Quite possible but as it is less active it may not cause as many problems.

Is this a drug to knock tysabri of its perch well on cost front.... an oligonucleotide could cost a few cents/pence compared to thousands o euros/dollars/pounds for antibodies. However the implication is that we could knock out/knockdown any of the 30,000 genes in the human or easily combinations of genes. This could be say an anti-sense LINGO-1 to promote repair. We could reinvestigate CD4 removal, we could knockdown CD20, CD19 of CD52, Sphingosine-1-phosphate etc, etc. The sky could be the limit. Neuroprotection or repair. This is the very exciting implication from this study. However we would have to work out how best to deliver to the brain.

However, We are still at it when it comes to MS trials, placebo control is name of the game, especially when pharma is involved.

The regulators and people on the ethics panels have yet to get the spine to say enough is enough. There are treament options for RRMSers, However, it seems OK that we can go to Eastern Europe and offer test or nothing.

Maybe I should shut my cakehole as maybe people are being offered something, when there maybe no treatment option, but if the regulators got a spine they could insist on head to head trials of active verses active. Would they get away with this in Western Europe or USA? But hey the EMA is largely funded by Pharma and would they bite the hand that feeds them

Roll on the time when a cheap generic arrives and this practise for DMT function will stop! Come on you Neuros make an effort and find a way to do it...For the sake of people in areas of "Have nots" when it comes to DMTs

In this day and age there should be no excuse not to offer some form of treatment for MSers in trials. However if they had done a none-inferitority trial (the drug is no worse than the comparator) compared to tysabri which is the obvious comparator they would have lost.  This is why pharma want to test their drugs against nothing so it stands a chance of looking better

CoI None


  1. My first thought on this was : wow, cool that antisense RNA at last seems to work in clinical studies... that was until I got to your comment on placebo studies ... and yes, dear MouseDoctor, it is NOT OK in this day and age to conduct placebo controlled trials in MSers.
    I am surprised this was allowed by the ethics committees ( unless the application for this study was filed a very looong time ago.)

  2. It is filed in Eastern Europe where western Pharma are using MSers as guinea pigs as people with a choice no longer sign up to placebo. There is one trial ongoing where 600 people are going to get nothing useful....I find this unbelieveable. We have had active drugs for MSers for the past twenty years long before was RNA was every thought up.

  3. Is it possible to get the names of the companies involved in studies thus formulated? This seems like a human rights violation. Are licensed physicians involved?

    1. Check out the the authors list... I think the answer to licensed physicians is yes

    2. This trial just sounds extremely improbable. Did it really happen? A study registered in Australia/New Zealand, started by a company nobody has heard, fronted by some German? researchers and recruiting in many different countries in Eastern Europe. Hmmm... Anybody who has ever been involved in international trials with multiple centers knows that they are a logistical myre and that only Big Pharma with Big Money and Big Presence in every country can navigate that sort of minefield safely.

  4. "However we would have to work out how best to deliver to the brain." The mechanism is to block translation of an integrin protein and prevent lymphocyte trafficking into CNS. Why would the anti-sense oligo need to penetrate the CNS?

  5. How does the antisense oligonucleotide get into cells? Are there other antisense-based therapies?

  6. It wouldn't for this indication as the idea is to target the immune response in the blood....however if you extend this to think about neuroprotection and repair..logically you want your inhibitor to enter the brain. That was my point

    1. Sure - but even outside of brain, transcription (and translation) does not happen in plasma. Still, despite problems with oligonucleotide cellular intake, there are at least two approved anti-sense drugs (according to Wikipedia); modified nucleotides are used to increase stability with respect to hydrolytic cleavage by nucleases. Was anything done to improve stability and cell penetration of the antisense strand in the MS study?
      Is RNA-i a better approach than antisense strands?


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