PTC Therapeutics Full-Length Huntingtin-Targeting Pill Comes Up Short, Setting Stage for Exon 1-targeting ddRNAi by UniQure

Today, PTC Therapeutics reported full results from a 52-week trial with PTC518 for Huntington’s Disease.  The data failed to support an intriguing early data cut last year that prompted Novartis to pay $1B for shared US profits and majority rights outside the US.  Unlike the previous n=32 data hinting at dose-dependent full-length huntingtin lowering (up to -43% in the CSF at the high dose) and corresponding improvements in functional outcome measures, the company had to dig deep to find hints of functional efficacy in today’s n=159 dataset.  In other words, an accelerated approval based on the PIVOT-HD trial is now highly unlikely.  Even huntingtin knockdown came down from -43% reported last year to the -20-25% range in the CSF and was not dose dependent.

That Novartis licensed the PCT molecule was surprising to me in the face of overwhelming evidence that protein derived from exon 1 huntingtin mRNA is the toxic molecule and increases in production as the CAG triplett somatically expands during the disease course (see this blog entry).  To me at least it seems that full-length huntingtin has fairly little to do with contributing to the disease.  Indeed, some had started to worry that targeting (full-length) huntingtin may even be harmful based on striatal atrophy caused by an antisense compound by Roche and Ionis (which I and others think can be attributed to the problematic phosphorothioate backbone chemistry of tominersen).  So at least in that sense, comfort can be taken from the PIVOT-HD results that there was no apparent worsening of disease caused by full-length huntingtin-lowering by the PTC518 splice modulator pill.

I can see that taking a once daily oral pill instead of drilling a hole in your skull may be preferable and an enticing prospect for a Big Pharma, but what good is that when the pill aims at the wrong target and will not work?  Of course, UniQure’s AAV-based DNA-directed RNAi therapy capable of targeting exon 1 mRNA will eventually be challenged and complemented by similar, but less invasive exon 1-targeting oligonucleotides or the nascent class of triplett expansion inhibitors, but a lot has to be said about the virtues of a drug that is not only targeted at the right transcript, but also where the exposure is limited to the main affected structure in the CNS.  

So while I understand that PIVOT-HD will cause some disappointment in the Huntington’s community, the data is making much more sense again from a mechanistic point of view following the confusion caused by the earlier data cut.  This should also give regulators further impetus to fast-track AMT-130 towards accelerated approval based on an upcoming 3-year comparison with propensity-matched natural history data.

Antisense Technology Is Feasable for Neurodegenerative Drug Development

Last week at World Muscle, ISIS Pharmaceuticals provided an update on their phase II study results for ISIS-SMNRx for the infant- and child-onset forms of spinal muscular atrophy (SMA).  Importantly, biomarker and biodistribution results were reported that clearly showed that ISIS-SMNRx is doing exactly at what it was designed to do, namely meaningfully increase target gene expression in the central nervous system (CNS).

The data not only greatly de-risk ISIS-SMNRx, but open up phosphorothioate-based antisense technology for a whole range of other, largely severe CNS-based diseases of high unmet need, including Huntington's disease, the spinal cerebellar ataxias, Alzheimer's, Parkinston's- you name it!

Biodistribution

Specifically, the data showed that despite only a focal, intrathecal infusion of the antisense drug into the lower spine, it readily distributed throughout the CNS up to the brain and at concentrations (10-30ug per gram tissue) that are strongly predicted to support both steric blocking and RNaseH antisense mechanism of actions in the CNS for 2' MOE chemistry.  Further chemistry improvements such as cET are opening the therapeutic window even more so.  What is more, these concentrations were maintained for months, thus further supporting the apparent therapeutic benefits seen in these open-label studies.

Note that the effective concentration for antisense mechanisms will differ according to target tissues; e.g. in the liver, largely due to competition from phagocytic Kupffer cells, the effective concentrations are 100ug/g and above with 2' MOE chemistry.

With the generous support of SMA families, the company was also able to look for the drug and the SMN protein in tissue sections from 3 deceased infants.  These investigations showed that the phosphorothioate oligo had been taken up pretty much in every neuronal and non-neuronal cell types. 

Such broad-based uptake may be quite important according to the opening keynote address of ISIS collaborator Don Cleveland last night at the annual OTS meeting in San Diego, given that expressions of disease-causing genes in various cell types, not just the neurons, seem to contribute to most neurodegenerative diseases.


Biomarker

In terms of drug action, the SMN protein was found to be re-expressed in the corresponding cells as intended for the splice-modulating approach of ISIS-SMNRx.  This was shown by immunofluorescent analysis.  Moreover, quantitative PCR showed that the expression of the intended full-length SMN2 mRNA was increased by 2 to 3-fold, consistent with the 2 to 3-fold increases in SMN2 proteins found from cerebrospinal fluid (CSF) samples in the child-onset studies.

No dose-limiting safety issues were seen and the intrathecal infusions which are predicted to be needed on a ~6 month-basis for many of the anticipated CNS-related antisense applications could be performed without having to resort to general anesthesia.

For SMA, genetically speaking all this essentially turns a type I infant-onset SMA baby into a less severe type II/III child, and a type II/III SMA child into a normal one, with the caveat that this benefit obviously only accrues from the time the drug is given which, unfortunately, may be too late for many type I SMA babies.  I was e.g. somewhat disappointed that no apparent correlation was seen between onset of antisense administration and therapeutic outcomes in the infant study, although clearly the numbers may well have been too small (n=20). I am very hopeful, however, that those infants making it out to say 18 months and beyond with ISIS-SMNRx may see very good outcomes indeed.

Despite the caution, all this was accompanied by apparent therapeutic benefits in terms of survival and muscle strength.  While highly intriguing, due to the open-label nature of the studies and the small patient numbers, it is not my intention to delve more into that aspect of the data and instead focus today on the truly mind-blowing pharmacodynamic data.  These should provide hope for many patients and families with neurodegenerative diseases. If not, we might as well give up on rational drug development.

 

Black Box Therapeutics Finds Small Molecule Cure for Spinal Muscular Atrophy

After curing Cystic Fibrosis and Duchenne Muscular Dystrophy with nonsense drug ataluren, PTC Therapeutics is moving on to relieving the sufferings of many more children afflicted with severe genetic diseases.  This time it is spinal muscular atrophy (SMA).  In a publication that recently appeared in SCIENCE, PTC Therapeutics has stumbled upon another orally bioavailable small molecule that is claimed to modulate an RNA processing event for therapeutic purposes.

The reason why I’m interested in the PTC story is that their small molecule approach to RNA modulation is counter-intuitive as it instinctively calls for a nucleic acid-based solution.  On the other hand, an oral alternative to what are usually more invasive routes of administration could have certain advantages such as patient convenience and access.

Naryshkin paper

The paper by Naryshkin and colleagues is on the discovery of RG7800, a compound partnered with the new LNA antisense owner Roche.  It is an illustration of the general strategy taken by PTC Therapeutics of finding RNA sequence-specific small molecule modulators of genes of interest. 

In this example, the company began the panning process by hooking up RNA elements from the SMN2 gene that are involved in the splicing of an exon of interest with a luciferase reporter gene so as to enable large-scale small molecule library screening.  If left untouched, this reporter construct will produce very little light emission due to luciferase expression.  On the other hand, if the small molecule is successful in biasing splicing towards the inclusion of exon 7, the intended outcome of this particular SMA treatment approach, then light is produced.

As one might expect there are numerous ‘hits’ that come out of such primary screens.  In this case, 2000 small molecules from the library increased luciferase expression.  Since such expression changes can be due to a myriad of causes, selected candidates were put through a number of tests such as whether the increase was dependent on the SMN2 sequence elements (reporter constructs without the SMN2 sequences would take care of this), whether the selected small molecules change the expression or splicing of other RNAs (à off-targets; e.g. by RNA seq) etc.

RG7800 apparently survived all these tests and was found to increase the desired SMN2 splice form by about 70% in a number of cell models (including patient-derived cells) and in a mouse model.  It also has entered clinical development.

Comparison with ISIS drug

Since RG7800 is in direct competition with antisense drug candidate ISIS-SMNRx by ISIS and Biogen as both aim to increase SMN2 exon inclusion, a brief comparison is warranted.

While RG7800 has the obvious advantage of being orally bioavailable versus the need for intrathecal administration of ISIS-SMNRx, in terms of molecular outcome, exon inclusion in spinal motor neurons, it appears to be lacking: a ~70% increase compared to ~100-150% increases in the good SMN2 isoform achieved by ISIS-SMNRx in two clinical trials in SMA infants and children, and even more than that in rodent studies before (Passini et al. 2011).    However, RG7800 achieves SMN2 splice modulation not just in the motorneurons of the CNS, but in many other places, in and outside the CNS. 

There is ongoing debate as to whether such body-wide modulation is required, a question also prompted by a study by ISIS and collaborators on the systemic/subQ application of the antisense drug (Hua et al. 2011).  Parenthetically, this also means that if ISIS/Biogen wanted global SMN2 regulation, they have an option with subcutaneous administration in addition to intrathecal administration.  Interestingly, with the subcutaneous administration of ISIS-SMNRx, the mice lived much longer than when the oligo was given intrathecally (days/weeks versus months).  Indeed, consistent with those studies, the PTC small molecule also prolonged the lives of SMA mice considerably.  

I guess it will have to be the clinical trials which will be most informative as to whether this is an artefact of the mouse model or not.  If so, systemic drug exposure would add no benefit and only increase the risk of adverse events from off-targeting.

At the end of the day, what I find remarkable is that it is apparently possible to find small molecules that can modulate gene expression in a fairly sequence-selective manner.  While I don’t doubt that you can change splicing with small molecules, it is the apparent specificity of a simple molecule such as RG7800 that perplexes me.  

PTC Therapeutics did not disclose how many compounds they had to sift through to find RG7800.  If they really just picked one or a few after the initial screen that yielded ~2000 hits and then got lucky, I’d be quite skeptical.  Adding to my skepticism is that drug concentrations in the CNS were reported that greatly (>10x) exceeded those in the plasma (supplementary figure S7).  I’m no small molecule guy, but for an oligo guy who has been following drug development in general, that seems very unique. The blood-brain-barrier apparently does not exist for PTC.  

As a result, and also given the controversy around the discovery of ataluren (artefact or not) and the fact that PTC Therapeutics itself can only remotely speculate on the mechanism of action of RG7800, I acknowledge the publication as interesting, but am not ready to jump on board just yet.

Oligonucleotide Therapeutics for Spinal Muscular Atrophy Impresses in Clinical Study

In addition to the continued validation of RNAi in Man, the other big winner of 2013 in the field of oligonucleotide therapeutics was single-strand phosphorothioate chemistry in the CNS.  Today, ISIS Pharmaceuticals announced clinical data from the most prominent candidate in that effort, namely ISIS-SMNRx for spinal muscular atrophy (SMA), a genetic muscle-wasting disease.  Following intrathecal administration of the splice modulating oligonucleotide, time- and dose-dependent improvements were observed not only in muscle function, but also in SMN protein production (biomarker), thus laying the foundation for an accelerated approval pathway.

In the open-label phase Ib/IIa study in ~30 children with the ‘less severe’ form of type II and III SMA, functional improvements of 1.5, 2.3, and 3.7 points on the HFMSE scale were seen at the 3mg (3 doses), 6mg (3 doses), and 9mg (2 doses) cohorts, respectively.  The changes were thus largely consistent with results from a previous similar, but single-dose phase I study where a 3.1 point increase could be observed at the 9mg dose.

Despite the generally positive news, the data raise a number of questions.  For example, optimal dosing frequency remains uncertain as there were similar functional improvements regardless of whether a single dose had been given or 2-3 doses.  This could have been due to the  long half-life of the drug and the time it takes from SMN protein production (as a  result of the splice modulation) to impacting motor neuron function.  Similarly, in the prior phase I study no positive changes in HFMSE scores were observed at the 3mg and 6mg doses whereas in the present study, improvements were reported.  Clearly, larger patient numbers are required  to settle on the optimal dose, and in fact this dose may not have been reached yet (note: a 12mg cohort has been initiated and children from the phase Ib/IIa trial are allowed to roll over to an additional dose of 12mg).

Case for accelerated approval?

Possibly foreseeing such issues due to small patient numbers, ISIS Pharmaceuticals and BiogenIdec recently developed an assay that allows them to measure SMN protein abundance in the cerebral spinal fluid (CSF).  It is the results from these measurements that provide a strong case for why ISIS-SMNRx should be made available (pending the 12mg results) before a larger phase III study will have been completed.  This is because the functional improvements were accompanied by increases in the SMN protein which also were dose-dependent with a more than doubling of SMN protein at 9mg.

In SMA, the SMN1 protein is missing due to mutations.  The therapeutic approach of ISIS-SMNRx takes advantage of the fact that humans have a pretty much identical gene to SMN1, SMN2.  The problem with SMN2, however, is that only ~10% of its precursor messenger RNAs is spliced into a functional SMN protein due to a difference in essentially just one nucleotide in exon 7.  The severity of the disease, i.e. whether somebody belongs to type I (most severe), type II, type III, or type IV of the disease depends on the copy number of SMN2 genes: 2 copies in type I, ~3 copies in type II and III, and at least 4 copies in type IV.

Therefore, doubling the protein output for type II and III patients (the patient population in the present phase Ib/IIa study) would appear to put the children into the type IV category in terms of protein output (correponding to ~6 SMN2 copies).  In contrast to type I-III, type IV results in no differences in life-expectancy and only in rare cases causes patients to be wheelchair-bound late in life.  

Severe disease of high unmet need, strong biomarker data with highly suggestive functional results, all dose-proportional…the ingredients for an accelerated approval. 

Just in: ISISis reporting preliminary data from a parallel multi-dose phase II study in the most severe, infant form of SMA (type I).  Although small in numbers, the fact that the 4 babies at the starting 6mg dose are still alive and without permanent respiratory support at an average age of 12.5 months appears to be much better than expected.  According to natural history data, you would have expected 2 babies either dead or on permanent ventilation by month 10.  

And finally...the ISIS-SMNRx results increase the value of Marina Biotech's CRN chemistry.  This chemistry competes with the ISIS 2'MOE chemistry employed in ISIS-SMNRx and appears to be of higher potency/affinity, but much less defined safety.

Next Stop: ISIS-SMNRx for Spinal Muscular Atrophy

In case you were wondering why RNA Therapeutics stocks have been going up and up regardless of the overall markets, it is because it is happening right now: RNA Therapeutics are claiming the role of the 3^rd major drug discovery engine, the most vibrant at that, following small molecules (withering) and recombinant proteins/monoclonal antibodies (running out of target space).  It therefore becomes important to anticipate the next major event on that road which are the results from two separate multi-dose phase II studies of ISIS-SMNRx to be reported sometime over the coming 6 weeks.

ISIS-SMNRx for the treatment of severe, orphan disease spinal muscular atrophy (SMA), a muscle wasting disease, is yet another powerful example of how RNA Therapeutics typically target the root causes of diseases rather than merely covering up their symptoms as drugs so often are designed to do, especially drugs for chronic illnesses. 

In SMA, the SMN1 gene is inactivated due to a mutation.  Luckily, there is another SMN1-like gene, SMN2, and this differs from SMN1 by one nucleotide.  As a result, splicing of SMN2 predominantly generates transcripts lacking an exon which in turn results in inactive SMN proteins.  Only a small fraction of SMN2 is spliced functionally.  By antagonizing a splice silencer element on the SMN2 precursor mRNA, phosphorothioate 2’MOE antisense ISIS-SMNRx redirects splicing towards the active form of SMN thereby rescuing the deficiency underlying SMA.  It is insights like these why you want your kids to study biology.  

Following intriguing phase Ib/IIa results from a small, open-label single-dose study in kids with type II and III SMA (‘moderate’ and ‘less severe’ forms of the disease) which showed dose-related continual functional improvements over 9-14 months, consistent with the long half-life of the oligonucleotide in the CNS, the multi-dose phase II studies aim to confirm that in a larger patient population.  In addition, a second phase II study is conducted in infants with the very severe type I form of the disease which results in nightmarish life expectancies of less than 2 years. 

   

It is the compelling scientific rationale, the 12mg dose, the preclinical efficacy and PK results at even smaller dosages and the tantalizing phase Ib/IIa results described above that you would think that the outcome from these two studies should be positive. 

If they are, expect them to be all over the news and RNA Therapeutics stocks continue their march upwards.

ISIS-SMNRx was discovered by ISIS Pharmaceuticals and is partnered with BiogenIdec.

  

ISIS-CRP Phase I Results: The Decreasing Competitiveness of RNaseH Antisense for Liver Gene Knockdown

To maintain is positive trajectory of the recent comeback, it is important for RNAi Therapeutics to firmly claim gene knockdown in the liver for itself.  This is because liver gene knockdown is the lowest hanging fruit for the technology, yet RNaseH antisense has proven to be capable of gene knockdown there as well.   If RNaseH were to crystallize as the preferred technology, it would jeopardize a considerable portion of the near to midterm market potential of RNAi Therapeutics.  Just think of Alnylam's 5x15(TM) portfolio of drug candidates.

As I have explained before, dose/tissue oligonucleotide concentrations and, related to that, safety/tolerability will determine which technology will win the competition.  Although the odds seem in favor of RNAi Therapeutics, ISIS Pharmaceuticals keeps promising that improved chemistry and screening methods will improve upon the modest potency (~30-35% ApoB knockdown) of and the safety concerns with mipomersen.  Due to the importance of liver gene knockdown to RNAi Therapeutics, this blog will continue to comment on the respective data points as they come in.

RNaseH Antisense CRP Phase I Data

Today, ISIS Pharmaceuticals announced phase I knockdown data from its c-reactive protein (CRP) program, ISIS-CRPRx.   CRP, a gene expressed by the liver, is believed (by some, not all) to act as a central player in a host of inflammatory diseases such as atrial fibrillation and rheumatoid arthritis.  Phase II studies for these indications are ongoing.

The phase I study tested whether ISIS-CRPRx can blunt CRP induction upon inflammatory stress.  Accordingly, healthy volunteers were dosed 6 times over 3 weeks with either 400mg or 600mg of the phosphorothioate antisense molecule against CRP.  Following that, subjects received endotoxin, a common laboratory reagent that is interpreted by the body as an infection.

Subjects treated with placebo saw an approximately 30-fold increase in CRP levels due to endotoxin.  When pre-treated with 400mg and 600mg, however, the induction was reduced by 36% and 63%, respectively.

 

Although the study succeeded in showing that ISIS-CRPRx could blunt CRP induction, it is much less clear whether ISIS-CRPRx makes for a viable therapeutic.  A 63% knockdown knockdown may be OK for some indications, but intuitively one has to wonder whether to stop an acute inflammation in its tracks you need to step much harder on brakes like CRP.  Indeed, the press release proclaimed, as a testament to the specificity of the drug candidate, that ‘other important immune modulators’ were not changed- somewhat puzzling given that CRP is thought to play such a central role in inflammation.

Be that as it may, what the press release did not mention was the side effect profile seen in the ISIS-CRPRx phase I study; to wit, safety and tolerability is the primary objective of any phase I study.  What concerns me is that mipomersen is 200mg weekly and causes injection side reactions, flu-like symptoms, and indications of chronic inflammation which are likely the result of the elevated steady-state tissue concentrations required for RNaseH antisense efficacy.  In the CRP study, 2- to 3-times more phosphorothioate antisense molecules were given.  Although the side effect profile of an RNaseH antisense molecule is also sequence-dependent, doses of 400mg and higher have historically been associated with toxicity/tolerability considered unacceptable outside of cancer.   

My prediction is that due to the poor efficacy-dose relationship, ISIS-CRPRx will not go into phase III.  We have to see whether the gen2.5 cET chemistry brings any significant increases in clinical potencies as inherent molecular potencies as measured in cell culture studies may not take into consideration other pharmacological rate-limiting factors.  If gen2.5 can lower liver tissue concentrations required to obtain 50% gene silencing into the low single-digit microgram/g range, RNaseH would become more interesting again for the liver.  Otherwise, it seems that more fertile hunting grounds for antisense technologies may be found in the areas of noncoding RNAs (e.g. microRNAs and lincRNAs) and therapeutic splice regulation, especially when the target molecules have a long nuclear residence time.  With ISIS about to present phase I data for its spinal muscular atrophy splice modulation drug candidate at next week’s AAN meeting, a next step into that strategic re-direction may be taken.

RNAi Therapeutics 2010: The Year of the SNALP

While the broad markets have enjoyed a considerable rally since the lows earlier this year, with the S&P500 up more than 65% since March, shares in RNAi Therapeutics companies have only initially participated, but then reversed course. This is unfortunate since this does not make establishing a broad drug development platform any easier with no products on or close to the market. I want to be clear though that one cannot blame it all on a market that 'does not get it' or just bad luck: strategic mistakes have been made, false expectations raised to a point that the market, and this might include Big Pharma, is saying ‘show me credible non-human primate, or even better, human data before I believe you’.

On the other hand, chaos brings with it opportunities, especially for companies that can emerge from this confusion with pre-clinically well-validated technologies and unambiguous proof-of-concept data for therapeutically relevant gene knockdown in humans. A lot will therefore depend on whether a single delivery technology, SNALP, can achieve such results. Results from both SNALP-ApoB (Tekmira), expected at the end of Q1 2010, and ALN-TTR (Alnylam) later in the year, provide opportunities for demonstrating efficacy in relatively small patient populations. Safety, of course, will be equally important to watch.

There are other RNAi Therapeutics candidates in the clinic among which maybe Benitec’s HIV program may provide molecular indications of antiviral activity with the rHIV-shI-TAR-CCR5RZ triple RNA(i)Rx combo. Cancer-related clinical results will mostly focus on safety, although ALN-VSP02 results could go into more mechanistic depths. Quark Pharmaceuticals’ candidates, of course, are far ahead of the field- sometimes I ask whether possibly too far ahead in light of what we have learned about the uptake of naked siRNAs and innate immune stimulation. Beyond RNAi Therapeutics, progress with mipomersen, DMD exon-skipping, and miR-122 inhibition for the treatment of HCV could help return optimism to RNA therapeutics drug development in general.

Taken together, I believe that 2010 could indeed be remembered as the RNAi Therapeutics Year of the SNALP, although it is always possible that a MEGA-deal, possibly inspired by the ApoB-TTR results could divert some of the immediate attention. Some of you may remember that I called out 2008, also for reasons related to SNALP, as the RNAi Therapeutics Year of the Liver. I still believe that this would have been possible if the attention had been focused properly on the exciting development path of this technology for liver applications some of which are now entering the clinic, instead of the somewhat broader messages the market received and is now struggling to cope with. After SNALP, cancer is a strong runner-up, and may in fact drive some of the major business developments of 2010. 2011 or 2012 may be the RNAi Therapeutics Year of Cancer outright.

Given my obvious fondness for liposomal delivery and to stay on top of the exciting scientific developments in this area, e.g. targeted delivery, I am already looking very much forward to be attending the annual International Liposome Society meeting in London next week. All the while next door Cancer RNAi Therapeutics company Silence Therapeutics, which also works on somewhat related lipid-mediated siRNA delivery, should be discussing their merger at the General Meeting and is just one more reason to go.

RNAi Therapeutics Portfolio Update

As we approach the New Year, I decided to take a look at the RNAi Therapeutics portfolio and finally take out gene therapy company Oxford Biomedica. This is not because I have lost faith in gene therapeutics, recent clinical data strongly suggest otherwise and the ocular/neuro applications approach that Oxford Biomedica takes, also in partnership with Aventis, should make this one of the companies in the field to watch. Oxford Biomedica, however, has done too little in RNAi Therapeutics drug development to justify its place in the portfolio. I still wonder how ocular DNA-directed RNAi Therapeutics for example could be institutionalized- maybe as part of a more general gene therapy company such as Oxford Biomedica, or an eye-focussed RNAi Therapeutics company employing both synthetic and ddRNAi techniques. Maybe even packaged into a re-formulated Targeted Genetics, yet another company that provided clear gene therapy clinical efficacy data for a rare eye disease. Until more strategic clarity is provided, however, including their continued interest in RNAi Therapeutics or not, I decided to sell some of TGEN as well.

The proceeds from these sales were put into ISIS Pharmaceuticals whose shares I believe have been oversold in the wake of the somewhat lukewarm phase III homozygous FH mipomersen results. Considering previous clinical results obtained with mipo as well as the overall favorable lipid profile changes as a result of ApoB knockdown, chances are that the upcoming phase III results in the other severe hypercholesterolemic populations will look better and signal the start of the manic phase of the manic-depressive mipo story.

Otherwise the portfolio should be well exposed to the potentially major value creating force in RNAi Therapeutics 2010 with Tekmira now making up the largest position in the portfolio, largely the result of the relative weakness in ALNY (-40%). Silence Therapeutics should warrant a re-evaluation after they make public their merger partner. AVI Biopharma remains on the radar for their involvement splice modulation (DMD foremost) and other areas that could provide them with near-term revenue, especially if they should move closer with mdRNA which could make for an attractive combination. Just fresh from the press is also the announcement that ISIS Pharmaceuticals will play a more active role in splice modulation.