Theme 13: In vivo Experimental Models

When you think of Orlando you think vacations, theme parks and sunshine. However, for one weekend in December, ALS/MND researchers from around the globe gathered in America’s sunshine state for the 26^thInternational Symposium on ALS/MND. This was the first Symposium I have attended during my PhD and I was excited to finally present all the research that the MND Association’s grant has allowed me to achieve over the past couple of years. Of course the unseasonably warm weather we enjoyed was a plus in comparison to what we left behind in the UK!

I primarily attended the conference to present a poster of my work entitled ‘Zebrafish C9orf72 loss-of-function models of Amyotrophic Lateral Sclerosis (ALS)’ as part of theme 13: in vivo experimental models. I was pre-warned these sessions are busy but nothing could prepare me for the real deal. With the draw of up to date scientific research (and a free bar!) the conference hall was packed with people networking and discussing their research. There was a great buzz and I thoroughly enjoyed the opportunity to discuss my work with researchers from around the world.

There was a great variety of work presented as part of theme 13, including in vivo models of C9orf72, SOD-1, FUS, TDP-43, Profillin-1 and Matrin-3 – to name but a few! It really highlighted to me the genetic heterogeneity of ALS/MND and the importance of generating models to investigate potential molecular mechanisms underlying the disorder.

As I work on zebrafish myself, I found poster p252, ‘’Identification of a novel neuroprotective drug for ALS using ‘ZNSTRESS’, a zebrafish high throughput phenotypic screen and validation in the SOD1 G93A mouse model’, of particular interest. The group successfully exploited the high-throughput capabilities of zebrafish. They used a transgenic SOD-1 zebrafish model of ALS to screen for neuroprotective compounds by utilising a novel fluorescent reporter that labels stressed neurons in the mutant zebrafish. The screen resulted in the identification of several hit compounds which play a role in reducing neuronal stress in the model. A lead compound that came out of the study is now being tested in a mutant SOD-1 G93A mouse model of ALS and preliminary data suggests the drug is safe. This study highlights the advantages of using zebrafish in high-throughput drug screens and how they can be used to identify promising compounds to test in murine models of ALS.

To find out about all the research from this theme, you can find the abstracts on http://www.mndassociation.org/research/international-symposium/abstracts-online/ and all the posters will be uploaded onto the F1000Research open access platform.

Overall, my first experience at an international conference was excellent – sun and science are a great combination. I have returned to the UK with an up to date knowledge on current ALS/MND research and lots of inspiration for my final year of my PhD. I would especially like to thank the members of the South Yorkshire branch of the MND Association for kindly providing funds in order to attend the conference – it has been an invaluable experience!

Session 2B: Clinical management

The first of the clinical sessions covered a variety of topics related to the clinical care and symptom management of patients with ALS/MND.

This session opened with Professor Orla Hardiman from Ireland speaking about the importance of specialist multidisciplinary clinics in the care of ALS/MND patients. There is evidence that patients who attend such clinics survive longer and have a better quality of life. Identifying the precise mechanisms by which these improvements are achieved are challenging hence the presentation title – Multidisciplinary care in ALS: Measuring the immeasurable? However health care professionals in this setting are able to work interdependently to guide patients through the complex multiple levels of decision making combining experience, judgement, scientific evidence and patient’s preferences and values in order to optimise the timing and effectiveness of interventions. This is not to ignore the importance and value of community based services in the support of patients with MND/ALS and Professor Hardiman talked about an ecosystem – which includes the patient/caregiver, community services and the specialist multidisciplinary clinic. If we can better understand the range and pattern of decision making practices associated with successful outcomes for patients and their carers this will inform the creation of more effective models of care.

The next speaker was Dr Richard Smith from California giving the results of a trial following anecdotal reports which suggested that Nuedexta may improve bulbar symptoms in ALS. Nuedexta containing dextromethorphan and quinidine is a drug that has been licensed and available in the USA since 2010 for the treatment of emotional lability (pseudobulbar affect). It was licensed by the EU in 2013 but is still not available in the UK.

The trial (cross over trial design) involved 60 patients treated for one month with Nuedexta or placebo then switched after a washout period for a second one month course of either drug or placebo as appropriate. They used a self report scale (Center for Neurologic Study-Bulbar Function Scale CNS-BFS) as the primary outcome measure which showed a statistically significant improvement in the mean score for the patient group compared to the placebo group with speech, swallow and saliva responding positively to treatment. Patients without emotional lability benefitted as well as those with emotional lability. Speech rate and swallowing time (secondary outcome measures) also responded to treatment although not statistically significant.

Dr Smith concluded that further work is needed to determine the duration of the treatment effect and whether Nuedexta is potentially disease modifying.

Dr Ed Kasarskis from the University of Kentucky then spoke about a small case series of the use of radiotherapy as a treatment for siallorhea which had not responded to medication. They used electron beam radiotherapy (EBRT) to a single parotid gland in 32 patients and found a reduction in saliva production which lasted over 22 months with minimal side effects. The non irradiated side also improved. The use of anticholinergic medication was able to be reduced or discontinued.

Finally Dr Bjorn Oskarsson from the University of California gave the results of a national study of muscle cramps in ALS. 282 ALS participants took part in an online survey and 92% reported cramps and for 20% this was their first symptom. For 62% of respondents cramps were the only source of pain. 36% took prescribed medication which included baclofen and gabapentin, 17% took over the counter remedies and 47% took no treatment. They did not find any correlation between disease duration or ALSFRS and frequency of cramps. 48% reported that their cramps had increased over time while 29% reported a decrease in frequency. Dr Oskarsson concluded that this study highlighted the clinical importance of cramps in ALS and further research on cramp symptom management is in progress in order to develop better guidelines for care.

Overall it was an interesting session with lots to take back to discuss with the team at King’s. Particularly keen to find out when/whether Nuedexta may become available in the UK. A good start to the rest of the symposium.

ALS HETEROGENEITY AND PROGRESSION

Here’s my blog from the fascinating session 4B at the Orlando Symposium.

Ammar Al-Chalabi takes the stage to a disco effect of flashing lights that might be more appropriate for the next speaker’s lurid pink suit, but he promises controversy regardless. His starting point is a definition of ALS that is about as uncontroversial as can be, but then he puts this into some historical context and points out how troubling ‘incomplete’ clinical forms can be for classification purposes, particularly if they then evolve into ALS. He wonders how many more syndromes will be removed from the MND diagnostic class given that MMN and KD have both been already withdrawn, keep going and we will all put ourselves out of a job eventually. He also points out how redundant ICD-10 classifications are, perhaps not that controversial, unless you wrote them (I’m guessing some of the audience members did). He sees ALS as a solar system of related conditions. He then presented the results of a brief survey he did amongst 72 global ALS experts to appraise what descriptive terms were actually in current use, the answer being ‘loads’. Confusingly most respondees felt their own approaches to be somewhat illogical (but seemingly irresistible) and what’s more we learnt that Australia is part of Europe. The diagnostic criteria don’t seem to improve matters either, despite serial revisions, and although they should assess the probability  of ALS being the phenotype, most neurologists don’t seem the find them useful. In essence there are a set of continuous variables that the clinical community feels the need to binarise (think hypertension) by setting a cut-off. To complicate matters further some of these variables (UMN burden for example) are hard to measure and perhaps non-stationary. Ammar’s proposed solutions include classification by underlying cause (where possible) and perhaps using symmetry as an additional phenotypic marker of slow progression. Mamede de Carvalho was clearly listening though and pointed out that monomelic disease can contradict this. Also we were urged to consider the intention behind the El-E criteria – for inclusion/exclusion to clinical trials, although as Ammar pointed out the label on the tin says ‘diagnostic criteria’.

Next up was Rick Bedlack of ALSuntangled fame. This presentation was of particular interest to me as it described a novel analysis of the PROACT database. I’ve also taken a look at this collection of outcome measures from numerous clinical trials, and we chose to concentrate on the reliability of initial rates of disease progression and how best to measure this rate over time, especially given that a good proportion of participants will drop out or die during the trial period. Our paper has just been accepted in the ALSFTD journal. I also noticed that a small proportion (under 1%) of participants seemed not to get any worse (or even got better by ALSFRS measures), my immediate assumption was that they probably didn’t have ALS, so I excluded them from further analysis. Rick Bedlack has taken a diametrically opposite approach in analysing data from ONLY these small number of participants, looking to find evidence in support of the apparently 21 sufficiently documented reversals of ALS progression that are reported in the literature. In summary it seemed more likely to happen in men with long disease durations, but he didn’t check the FVC data yet. What’s happening here? He doesn’t know, but likens it to HIV ‘elite controllers’, and thinks it’s a topic worthy of significant further research. Of course there are sceptics in the audience (you can have stable disease and improve ‘function’ with cunning life adaptions), but an on-the-spot show of hands suggested that about 1% of audience members had witnessed similar phenomena in their patients. So. It’s just been published in Neurology.

Team Utrecht was up next with Henk-Jan Westeneng predicting survival in ALS patients by integrating multiple data sources. This looks like proper data-driven personalised medicine and it also seems that Dutch doctors wear fetching short-sleeved white coats. The variables were narrowed down using a Cox model but sadly imaging parameters (so far…) don’t seem to improve the prediciton accuracy. Data from 2000 patients showed the ALSFRS slope to be most predictive, but 8 variables were independently contributing and survival in various countries seems quite similar. Questions concerned the effect of imputing missing data (you can tolerate ‘known unknowns’ here apparently) and seemingly 70% of patients like to get an (emphasis on uncertain) estimate of prognosis. A patient-friendly version with readily understandable data is planned for easy web access.

Patricia Andres then described data generated by quantitative strength testing using the ATLIS system with a view to improving the efficiency of future clinical trials. This will be essential to detect small effects within a heterogenous population. She also reminded the audience that QoL measures are REQUIRED in phase 3 clinical trials. The concept of functional cliffs was introduced, for example steps between ASLFRS grades are not even, so the scale is best reserved for large trials that can average out this fluctuation. The pros and cons of quantitative muscle testing were introduced and her dataset of 63 patients with 3 or more visits described. The impact would decrease the sample size required by about a third over using ALSFRS. Basically it just reminds us how useless the ALSFRS is on an individual basis. Conclusions: Invest in outcome measures… and consider use of a lead in phase.

Last up was Susana Pinto from Lisbon, reminding us that respiratory failure limits life-expectancy for people with ALS. They have 15y of clinic data and she agrees there can be a symptomatic improvement, e.g. if you no longer walk much so you don’t feel breathless. Conventionally though we directly measure the strength of ventilatory muscles, they typically did this at 4 month interval visits. FVC and SVC are highly correlated at both time points and generally there’s lots of correlation with the other respiratory measures also. For example both FVC and SVC are dependent on MEP. Correlations are a bit weaker in patients with bulbar onset, SVC might be a bit more accurate for them (less air leak, but then they don’t use whole face masks in Lisbon apparently), but would SNIP be a better measure all round? We don’t know. It also remains uncertain the impact of NIV on these measures.

That’s all, thanks for reading.

 

 

First Impressions

Rachel Boothman, Head of Education and Information, MND Association

With a few days to digest all that happened at the 26^th International Symposium on ALS/MND……here are some reflections from a first timer.

My Hopes

Having recently moved into a new education role at the MND Association, I was armed with a ‘to do’ list of networking, horizon scanning for developments in respiratory/nutritional care and relaying learning via our online professionals forum. I was also tasked with the honour of helping to judge the clinical poster prize alongside two renowned neurologists from the USA and Australia.

Every year, we hear about the fantastic collaborations, projects and new discoveries that emerge from this annual gathering, but I didn’t wholly understand the enormity and significance of this international community until experiencing it first hand.

It is a challenge to articulate the scale and breadth of work going on across a whole raft of subject areas, which range from complex clinical trials to very simple changes in care pathways which can make a significant difference to those living with and affected by MND.

Networking

Delegates heard about the results of collaborations formed at the last year’s Symposium and new links were made this year, which will no doubt prevent duplication of work. I was able to hook up with my counterpart at the ALS Association and we have already made contact via email since arriving home! There were also opportunities to share ideas and resources around developing services for children and young people affected by MND. If that’s not enough, I learned how the ‘tweet’ and share information on social media!

The Poster Prize

The poster exhibition hall alone was the size of an aircraft hanger, half of which was dedicated to more than 300 poster displays from all corners of the globe.

The objectives of the poster prize are three fold:　to increase the profile of the poster sessions; to recognise the quality of the work presented and to reward presenters for outstanding work. Two final prizes were awarded, one selected from the clinical and scientific programmes, respectively. The prize itself is a certificate and a medal.

Ed Kasarskis from the USA and Matthew Kiernan from Australia joined me on the judging panel and delegates were allocated ten minutes to present their posters and answer questions. We were delighted to award the prize for the clinical poster to Dr Rebecca (Becky) Broad from the University of Sussex in the UK. Her poster “Neurite Orientation Dispersion and Density Imaging (NODDI), was in the Imaging and Electrophysiology theme and demonstrated microstructural changes association with MND.

Sessions

For me, the sessions which resonated most were those on cognitive change (assessment and management) and the impact of strain on family/informal carers. It was great to hear about work underway in Cambridge, UK which considers the impact of cognitive change on carers and that guidance is being drafted which will provide non-pharmacological strategies and tools to help manage this.

……and finally

The phenomenal energy, commitment and drive to find new management techniques, treatments and eventually a cure for MND, was evident throughout the Symposium and I heard several delegates state ‘it was the best yet’. If I had to use three words to surmise my experience, I would quote my tweet from the final day – inspiring, humbling and hopeful!

 

Session 4A: Disease Models

Firstly, Dr Cathleen Lutz (The Jackson Laboratory, USA) discussed the range of current mouse models of MND and the potential for generating new models.  Lutz explored the many reasons why MND is a hard disease to model, and how the SOD1-G93A model has become the ‘workhorse’ for MND mouse modelling.  However, as subgroups and new genetic mutations of MND are identified, new avenues for creating mouse models are opening up.

Models of SOD1, TDP43 and C9ORF72 were discussed, highlighting the ever-increasing array of MND mouse models which all have their own advantages and disadvantages for use.

With new CRISPR technology, new models can be created on different genetic backgrounds much faster and more efficiently than previously, which raises the question of whether we should be exploring the effect of genetic background variations on each of the models.  Currently models are made using inbred strains to avoid genetic variation.  However, is it more representative to create population models of the disease, in which there is genetic variation, as would be seen in samples of patients?

 

Dr Adam Walker (now at Macquarie University, Australia) presented data on a mouse model of TDP-43 from the University of Pennsylvania, USA.  A mouse model was created which expressed hTDP-43∆NLS when doxycycline was withdrawn from the diet; dosing with doxycycline suppressed expression.  Mice were characterised after withdrawal of doxycycline and recovery was also investigated when mice were fed doxycycline after a 6 week withdrawal period.

Mice were found to express hTDP-43∆NLS in the brain and spinal cord after 1 week of doxycycline withdrawal and had TDP43 pathology in the brain and spinal cord.  A progressive motor phenotype was evident from 2 weeks post-withdrawal with brain and muscle atrophy by 4 weeks post-withdrawal and spinal cord motor neuron loss from 6 weeks post-withdrawal.  The end stage of the disease course was around 10 weeks post-withdrawal but cause of death was unclear.

Conversely, when fed doxycycline after a 6 week withdrawal period, TDP43 pathology was cleared, reinnervation occurred, motor phenotype improved and death was prevented.  This model therefore provides promise that potential therapies for MND may halt disease progression and improve symptoms, even at the late stages of disease.

 

Following this, Dr Qiang Zhu (University of California, USA) presented on the development of mouse models of C9ORF72.  Mouse models for loss and gain of function were discussed, as the mechanism of C9ORF72 in MND is under debate.

Loss of function was modelled using a knockout of C9ORF72, in which the heterozygous knockout mouse showed no significant defects and normal survival.  The homozygous knockout mice showed no signs of a motor phenotype but did show signs of mild age-dependent social changes.  However, the homozygous knockout mice also developed T-cell lymphoma (C9ORF72 is a tumour suppressor).

Gain of function was modelled using an insertion of GGGGCC repeats in C9ORF72.  The BAC transgenic mice showed repeat size, expression-dependent repeat-associated non-ATG (RAN) foci and RAN products accumulation, age dependency of RAN aggregate formation, hippocampal neuron loss, increased anxiety and impaired memory and learning ability in an age-dependent manner.  Moreover, the efficacy of anti-sense oligonucleotides (ASO) was tested in these transgenic mice.  ASO treatment significantly decreases repeat-containing RNA, RNA foci and polydipeptides without significantly reducing overall C9orf72.

These models suggest a potential role of loss and/or gain of function in C9ORF72 MND, and demonstrate the efficacy of ASO therapy.

Withdrawal of ventilation support at the request of a patient: the ethical, moral and legal issues

Motor neurone disease (MND) can cause weakness in the chest muscles involved in breathing. This leads to shortness of breath and symptoms including disturbed sleep and headaches. Ventilation support allows a person to breathe more efficiently and can also extend survival.

The MND Association has funded research into respiratory management and ventilation support for people living with MND.

A study looking at withdrawing ventilation support at the request of a patient with MND has recently been published in the journal BMJ Supportive and Palliative Care. It was led by Professor Christina Faull, from LOROS – the Leicestershire and Rutland Hospice – in conjunction with the University Hospital of Leicester, and has been part-funded by the Association.

Healthcare studies are an important part of medical research. Their purpose is to try and solve issues surrounding treatment and management, to improve the delivery of care to patients, and improve support for their families. This type of research also helps provide evidence that a treatment is helpful and beneficial for the clinical commissioners, who, in turn, provide funding for the treatment and support.

Ventilation support  

The main treatment to help people living with MND breathe is non-invasive ventilation (NIV), though it is not suitable for everyone.

NIV involves a machine that supports breathing by increasing the amount of air that can be breathed in. This is done through a mask over the nose (or nose and mouth).

NIV is often first used during the night, in response to difficulties in sleeping associated with breathing. However, as MND progresses, patients can become more reliant on NIV and may also use it during the daytime.

Patients may also receive ventilation support via invasive ventilation tracheostomy – this is where a tube is inserted into the windpipe through the neck, which is attached to a machine that can help with breathing.

More information on ventilation support can be found in our Care Information Sheet 8B.

Withdrawal of ventilation

Someone currently using ventilation support can request to withdraw it even though life may be shortened once this treatment is removed. There may come a time when a person with MND feels that breathing support is no longer helping or it has become a burden.

People who have MND and are receiving ventilation support should know that withdrawal is an option available to them. When discussing this request with their doctor they should get the help and support they need to make their decision.

Withdrawing ventilation support has been a difficult topic for both health-care professionals and people with MND to discuss, over fears that withdrawing treatment may be seen as assisting death. It is important to stress that withdrawing ventilation support is not legally classified as assisted dying.

Study findings

Interviews with 24 doctors with a range of specialities shared their experiences of withdrawing ventilation support at the request of a patient with MND.

The interviews revealed that doctors had many concerns about withdrawing ventilation support from their patients. These were divided into concerns about their role as a doctor and duty of care, about why their patient was asking for treatment to be stopped, and, if they did so, whether this would be classified as assisting the patient to die and therefore breaking the law.

Doctors had also experienced difficulties in talking about this topic with their colleagues, with patients with MND and with families, especially if the person with MND had difficulties with communicating their wishes.

Professor Faull, lead researcher on this study said “Many doctors had experienced negative reactions from other healthcare professionals when these colleagues were unclear of the distinction between palliation of symptoms, withdrawal if treatment and assisted death.

Prof Christina Faull, LOROS

“The research we carried out found that guidance is needed for professionals who support a patient with MND who wishes to withdraw from ventilation. Open discussion of the ethical challenges is needed as well as education and support for professionals.”

Professor Faull is currently involved in developing guidance for healthcare professionals on the withdrawal of assisted ventilation at the request of a patient with MND. This is in conjunction with the Association for Palliative Medicine, with support from the MND Association and is expected to be published in autumn 2015.

More information:

Research paper: Phelps, K et al. BMJ Supportive and Palliative Care Published Online First, Open Access (11 Sept 2015) doi: 10.1136/bmjspcare-2014-000826

Care information sheets 8A Support for breathing problems, 8B Ventilation for motor neurone disease, and 8C NICE guidelines for non-invasive ventilation (NIV)

End of Life Guide

Association for Palliative Medicine Position Statement: Withdrawal of ventilatory support at the request of an adult patient with neurological or neuro-muscular disease.

Information sheet for professionals P6: Evaluation and management of respiratory symptoms in motor neurone disease.

This blog has also been posted on the MND Association’s research blog.

Allied Professionals Forum – abstract deadline fast approaching!

My name is Rachel Patterson, and I am the General Manager of the International Alliance of ALS/MND Associations.

I’m writing this ReCCoB post to make you all aware that the deadline for abstract submissions for the Allied Professionals Forum is this Monday (15 June 2015)!