Antisense Therapeutics reports ‘strong initial efficacy’ for Duchenne Muscular Dystrophy drug in Phase 2 trial

Biopharmaceutical company Antisense Therapeutics (ASX: ANP) emerged from a trading halt to announce that its immunomodulatory therapy, ATL1102 for Duchenne Muscular Dystrophy (DMD) had met the required safety standards and achieved “strong initial efficacy” as part of its Phase 2 clinical trial.

Trial results were also vocally supported by a slue of scientists, researchers and other medical professionals who were aware of the trial’s parameters and endpoints.

The Phase 2 trial involved administering the drug once per week via subcutaneous injections for 24 weeks in 9 non-ambulatory DMD patients.

Overall, the study showed that administering ATL1102 resulted in “consistent improvements or stabilisation across the different measures of motor function and strength”.

The news means ATL1102 is likely to be advanced into a “pivotal” Phase 2b trial that could get up and running before the end of the year.

Moreover, the company stated that final trial results also confirmed the drug’s positive effects on secondary trial endpoints that assessed its activity and efficacy including measuring the effects on immune cell numbers in the blood and measuring the participants’ functional capacity.

Additionally, Antisense reported that MRI assessments of patients’ upper limb muscles had shown the drug’s apparent beneficial effects in stabilising the fat fraction percentage within the muscles of the forearm.

According to Antisense, the data showed a stabilisation in the percentage of fat in the forearm muscles and an increase/maintenance of functional muscle mass, which is both “outstanding” and “unexpected” for a drug treating the inflammation.

Researcher Dr Valeria Ricotti from the Great Ormond Street Institute of Child Health University College London in the UK explained that based on the MRI data, the observed stabilisation in the percentage fat fraction with ATL1102 treatment “would not be expected in the natural course of disease in DMD even under corticosteroid treatment”.

“Furthermore, the stabilisation of fat fraction percentage combined with the observed maintenance/increase of remaining muscle area is suggestive that ATL1102’s effect could preserve the contractile muscle mass,” she said.

“The study met its primary endpoint showing ATL1102 to be safe and well-tolerated with no serious adverse events being reported and no participant withdrawing from the study. With very few treatment options for boys with Duchennes who are no longer ambulant, it has been great to enable the boys to participate in this clinical trial and I am most encouraged by the outcomes of the study,” said Dr Ian Woodcock, principal investigator of the ATL1102 Phase 2 DMD trial.

Treating Duchenne Muscular Dystrophy

DMD is a severe type of muscular dystrophy that begins in early childhood and progressively gets worse through persistent weakening of muscle tissue. According to scientific research into the rare genetic disease, almost complete muscle loss typically occurs first in the thighs and pelvis followed by the arms.

Currently, around 300,000 people suffer from the disease globally with no known cure or effective treatment available. Sufferers are often prescribed corticosteroids which help to soften outward symptoms in the short-term, although long-term treatments have been lacking.

Existing medications such as ataluren have been approved for limited use in the EU while what’s known as the “antisense oligo” golodirsen was approved for medical use in the US last year.

Next trial stage

Following the amiable results from the DMD trial, Antisense said it now intends to put ATL1102 forward for a Phase 2b trial.

The company said that scientific advice meetings have already been held with three European regulatory authorities, each of whom affirmed general acceptance of the proposed trial efficacy endpoints, safety monitoring plan, dosing duration of 12 months and the use of higher doses.

As thing stand, the biopharmaceutical company has lodged a submission to the European Medicines Agency for Scientific Advice with the results of their evaluation due “mid-year”. Once a response is received and evaluated, Antisense said it will prepare and submit a fully-fledged clinical trial application in Europe and the UK.

The company is also actively preparing submissions for orphan drug designation for ATL1102 in the US and the EU.

Encouraged by observations of the anti-inflammatory actions of ATL1102, Antisense declared it would also investigate other potential diseases including those that are inadequately controlled with corticosteroids such as other muscular dystrophies and neurological conditions.

“Our focus is to continue planning and to methodically and efficiently move our DMD program through Phase IIb in Europe,” said Mark Diamond, CEO of Antisense Therapeutics.

“As we gain further certainty from the regulatory process on the parameters of the next trial, which may lead to early market approval, we will assess funding and trial management options and also engage in discussions with interested potential partners ahead of commencement of Phase 2b. This will allow the Company to consider the most advantageous way to proceed with the pivotal trial on its own or with a partner,” Mr Diamond said.