1. What is utrophin?
Utrophin is a naturally occurring protein that is functionally and structurally similar to dystrophin. Utrophin is produced naturally during the early stages of muscle fibre development but is switched off in maturing muscle fibres, at which point dystrophin is produced to perform the same functional role. When a muscle fibre is damaged, utrophin is also produced during the early stages of the repair mechanism. Our utrophin modulation approach aims to use small molecule drugs to maintain the production of utrophin to compensate for the absence of dystrophin in DMD patients and so protect healthy muscle function.
2. The lead utrophin modulator is SMT C1100. What is this and how does it work?
SMT C1100 is a small molecule experimental medicine that is administered orally. We believe SMT C1100 could maintain muscle health by keeping production of utrophin switched on to substitute for dystrophin.
3. How many clinical trials has SMT C1100 completed and what have you found in these trials?
SMT C1100 has completed two Phase 1 clinical trials in healthy adult volunteers, for a total of about 100 people, and two Phase 1 clinical trials in patients with DMD, for a total of 24 patients. Throughout these trials, SMT C1100 has been well-tolerated, and the most frequent adverse event is pale stools caused by the unabsorbed product candidate. We have also found that SMT C1100 is best absorbed by patients on a balanced diet of fats, carbohydrates and proteins, who take a small glass of full fat milk with SMT C1100. With this regimen, we believe that all patients who are administered SMT C1100 may be able to sustain utrophin protein expression and that could lead to clinical benefit.
4. At what stage of development is SMT C1100? Where will its clinical trials take place?
We have received approval to commence a Phase 2 proof of concept trial in the UK. It is expected that this trial will also include sites in the United States. More details will be provided in due course.
5. When will the UK and US sites begin enrolling patients?
We have received regulatory approval in the UK to initiate PhaseOut DMD and expect to enroll patients in the UK soon. In the US, we expect to begin enrolling patients in the third quarter of this year, subject to US Food and Drug Administration regulatory approval of the trial design.
6. How long will the Phase 2 proof of concept trial last?
This is a 48 week trial with the potential for an extension period.
7. Who will be able to participate in the Phase 2 trial?
It is expected that the Phase 2 proof of concept trial will enrol up to 40 boys ranging in age from their fifth to their tenth birthdays. The boys must be able to walk at least 300 meters unassisted in six minutes, and also must be on a stable regimen of steroids for at least six months prior to their enrollment. There are additional inclusion and exclusion criteria, and the physicians conducting the trial will evaluate potential participants against these criteria to determine who could safely participate.
8. Are there any restrictions on the dystrophin mutation in your trials?
We believe utrophin modulation has the potential to treat all patients with DMD, regardless of the underlying genetic mutation of dystrophin. Therefore, there is no restriction on genetic mutation and the trials are expected to enrol all patients who meet the inclusion and exclusion criteria.
9. What endpoints will be in the Phase 2 proof of concept trial?
The primary endpoint of the open-label trial is the change from baseline in magnetic resonance imaging parameters related to fat infiltration and inflammation of the leg muscles. Additional endpoints include utrophin protein and muscle fibre regeneration measurements from muscle biopsies, safety and pharmacokinetic measures and exploratory functional measures including the six-minute walk test, North Star Ambulatory Assessment and patient reported outcomes.
10. Why do you need to collect biopsies?
The biopsies are currently the only way to study the effect SMT C1100 is having on utrophin protein in a patient’s muscles. We believe that collecting these data will be important in understanding the effects of SMT C1100.
11. How will you know if SMT C1100 works?
We are looking at many different endpoints to examine the efficacy of SMT C1100. Each one of those efficacy endpoints could signal that SMT C1100 is having a positive effect on patients, but we would need to see consistent data on that endpoint within the trial population to determine if the effect is related to treatment with SMT C1100. From there, we would likely need to conduct a larger clinical trial to confirm our findings. If we believe the data support a regulatory filing for SMT C1100, we would then present them to the regulatory authorities, which would decide if there is enough evidence of safety and efficacy for approval.
12. Why should I consider participating in future clinical trials?
While no personal benefit can ever be guaranteed by participation in a clinical trial, there are other potential benefits, including allowing you to play an active role your healthcare and helping others by contributing to the better understanding of DMD.
13. I live outside of the countries that are currently enrolling patients in a clinical trial. Can I enrol in one of these sites?
The decision on who can enrol in a trial is up to the participating physician.
14. Where can I find more information about your clinical trials?
More information on PhaseOut DMD is available on the EU Clinical Trial Register. Additional information about our clinical trials will be posted as it becomes available on www.clinicaltrials.gov. You can also sign up for email alerts from Summit at www.utrophintrials.com.
15. Is it possible to get access to SMT C1100 under compassionate use?
At this time, we do not provide access to SMT C1100 outside our clinical trials. We are focused on getting SMT C1100 available to all patients as quickly as possible and believe this will be achieved through demonstrating its efficacy and safety in well-designed clinical trials.