dm+d

Unassigned

New Medicines

Duchenne muscular dystrophy

Information

New molecular entity
Pfizer
Pfizer

Development and Regulatory status

None
Phase III Clinical Trials
Phase I Clinical Trials
Yes
Yes
Dec 20Also has orphan drug status in US [6].
Oct 20Granted fast track designation in US [5].
Aug 18Granted orphan drug status in EU [3].

Category

An in vivo gene therapy, given as a single dose, that uses a recombinant adeno-associated virus serotype 9 (rAAV9) capsid to deliver a shortened version of human dystrophin gene (mini-dystrophin) under the control of a human muscle-specific promotor.
DMD affects about 1 in 3,500 newborn males [1].
Duchenne muscular dystrophy
Intravenous infusion

Trial or other data

Nov 21PIII CIFFREO trial (NCT04281485) is recruiting and is now expected to complete collection of primary outcome data in Feb 23 [10].
Sep 21Pfizer announced plans to narrow trial inclusion criteria after 3 serious adverse events of muscle weakness of which 2 involved myocarditis in ongoing studies of fordadistrogene movaparvovec. The company’s External Data Monitoring Committee determined the adverse events were associated with the treatment and that specific mutations in the dystrophin gene are potentially linked to a higher risk for the problems (i.e. exon deletion or duplication, insertion, or point mutation affecting exons 9 through 13 inclusive, or a deletion that affects both exon 29 and exon 30). The company has proposed that pts with these mutations, who represent < 15% of all pts with DMD, are being excluded from trials going forward.[8,9]
Dec 20PIII study (NCT04281485) is recruiting in Israel and Spain (no UK sites); expects to complete collection of primary outcome data in Sep 2022 [7].
May 20PIb data show that 1 year after treatment, 6 pts (three given low dose and 3 given high dose) improved by an average of 3.5 points on the 17-point NSAA scale. Pts given low-dose group had dystrophin levels that were 24% of normal and pts given high-dose group had levels that were 51.6% of normal. With respect to safety, 3 pts required hospitalisation due to side effects (1 needing antiemetics and fluids to treat dehydration from vomiting, 1 needing dialysis and Soliris for AKI and complement activationa and another needing a platelet transfusion and Soliris to manage low platelet count and complement-linked side effects). The immune side effects are considered to be due to the adeno-associated virus (AAV) used to deliver the treatment. [4]
May 20PIII study to evaluate the safety and efficacy of PF-06939926 gene therapy in boys with DMD starts (NCT04281485). 99 boys aged 4 to 7 years will be recruited (sites not yet stated). The one third of participants who are randomized to the placebo arm will have an opportunity for treatment with gene therapy at the beginning of the second year. All boys will need to be on a daily dose of glucocorticoids (prednisone, prednisolone, or deflazacort) for at least 3 months prior to enrolling and to stay on daily glucocorticoids for the first 2 years of the study. All boys will need to be negative for neutralizing antibodies against AAV9, as measured by the test done for the study as part of screening. Primary outcome is Change from Baseline in North Star Ambulatory Assessment (NSAA) at week 52; collection of these data is due to complete Apr 22 [2].