Research

The Fifth Annual CHDI Therapeutics Conference took place February 8-11 in Palm Springs, CA. Two hundred-fifteen scientists from 18 countries gathered to attend presentations on the most recent developments in HD research, and to share their findings and thoughts on a variety of topics, all relating to developing therapies for HD. Complete coverage of the conference will be forthcoming from Dr. LaVonne Goodman, as well as a video postcard from the conference by Charles Sabine. In the interim, here is LaVonne's report on the most exciting presentation at the conference, the results of the MermaiHD Trial of ACR-16 (Huntexil) in Europe.

MermaiHD ACR-16 (Huntexil) Trial Results:  Good News from Europe

By Dr. LaVonne Goodman

In an important highlight from the 2010 CHDI meetings, Dr. Joakim Tedroff from NeuroSearch presented preliminary results from the Phase 3 ACR-16 (Huntexil) trial in Europe. This trial will almost certainly bring forward a new drug treatment for Huntington's (HD) that significantly improves, not just stabilizes motor ability. Trial results also showed a trend toward cognitive improvement, and very importantly showed that there were no significant drug side effects. This drug is not only effective, it has safety features to allow its use in all those with HD.  And in other promising news outside of the trial, NeuroSearch has shown that metabolic improvement occurs in the the brains of Huntington's patients who have taken the drug.

As in the North American trial, this study has 3 different groups; those who received placebo, or a lower dose of drug (45 mg/day), or a higher dose of drug (90 mg/day).  But differing from the North American trial, a fraction of each group in the European trial was allowed to take neuroleptic (antipsychotic) medications in addition to study drugs. 

Results from preliminary analysis:

  • The benefits of Huntexil were seen only in those on the larger dose of drug.
  • For those on the larger dose, there was significant improvement in the TMS (total motor score) on an average of about 3 points. This translates to about 1 year of the motor changes predicted to occur for disease progression in HD.
  • The improvement occurred only in the voluntary movement component of the TMS which means those aspects of HD that cause slowness of movement and rigidity, but had no effect on chorea.
  • The improvement in voluntary movement persisted through the 6-month duration of the trial and seemed to increase with time.
  • There was improved oculomotor (eye movement) function, as well as dystonia (involuntary rigid muscle contractions).
  • There was trend in improvement in several cognitive (thinking) measures.
  • There were no significant side effects.
  • There was no change in total functional capacity (TFC) scores.
  • The use of neuroleptic (antipsychotic) medication had no effect on Huntexil benefit.

More questions:  And though this part of the data analysis has not been completed, NeuroSearch will be able to assess whether the drug benefit varies with the stage of the disease.  But as happens in all clinical trials there are unanswered questions that will require more human study.

  • What is best effective dosage? While the lowest effective dose was established in the trial, it is unknown whether a larger dose might - or might not -- be more effective.
  • What is the effect when Huntexil is combined with Xenazine (tetrabenazine)?

 

Author's Comments: Although some might be disappointed that the beneficial effects seen in this trial aren't greater, these results are truly cause for celebration. This drug improves voluntary motor function and probably improves aspects of cognition as well. We've learned that the effect lasts 6 months with possible improvement for a longer period of time. And if this weren't enough, Huntexil might modify the course of the disease since the effect of Huntexil seemed to increase with time.  And it is safe for use in all people with HD.

Bottom line: This drug is a real winner. And as fast as possible we need to push enrollment over the top for ACR16 in North America.  Sign up today.

With gratitude:  Every person involved in this successful trial, or any other clinical study or trial that increases our knowledge for Huntington's disease deserves our utmost gratitude.  We thank the participants and their families, who while doing the hard work of living with HD step up to the plate to join clinical trials.  We thank the sponsors like NeuroSearch who risk years of time and millions of dollars along the long path of drug development. We thank all Huntington organizations: the European Huntington Disease Network (EHDN) and the North American Huntington Study Group (HSG) that work to advance all levels of research for Huntington's disease.   We thank CHDI who will help coordinate efforts allowing trial participants to receive Huntexil during the open label portion of the trial.  We thank all of our volunteer organizations across the world who reach out to increase awareness of clinical studies and trials.

Working together there is promise of even greater things to come.