#MDA2021 — Patients Switched to Emflaza for Efficacy, Tolerability

Editor’s note: The Muscular Dystrophy News Today team is providing in-depth coverage of the 2021 MDA Virtual Clinical and Scientific Conference, March 15–18. Go here to read the latest stories from the conference.

Switching from prednisone to Emflaza (deflazacort) successfully met efficacy and tolerability goals in most patients with Duchenne or Becker muscular dystrophy, as reported by their neurologists.

During a follow-up period of six months, clinicians reported that the switch was at least “somewhat” effective in more than 90% of cases.

“We’re encouraged by the clinical benefit exhibited by patients taking EMFLAZA in this real-world analysis,” Stuart Peltz, PhD, CEO of PTC Therapeutics, the therapy’s developer, said in a press release. “This data supports the results that we saw in patients on corticosteroids in the placebo arms [groups] of multiple Duchenne clinical trials and what we have heard from the Duchenne community.

“We are committed to providing access to clinically differentiated treatments for patients with high unmet need,” he added. 

The findings were presented at the 2021 MDA Virtual Clinical & Scientific Conference in a poster titled “Steroid Switching in the Treatment of Dystrophinopathies in the US: a Nationwide Chart Review of Patient Characteristics and Clinical Outcomes.“

Immunosuppressive corticosteroids reduce inflammation and slow the decline of motor and lung function; they are the standard treatment for muscular dystrophies.

Emflaza is an immunosuppressive therapy approved to treat Duchenne muscular dystrophy (DMD) in patients 2 years or older. 

After its approval, some physicians switched their patients to Emflaza from prednisone, a frequently used immune-suppressing corticosteroid. However, there is evidence from clinical trials that suggest differences in adverse events (side effects) and clinical outcomes in those treated with Emflaza compared to this corticosteroid therapy.

In a collaboration with the Analysis Group and Children’s Hospital Colorado, PTC designed and funded a study to understand the reasons for switching from prednisone to Emflaza and assess clinical outcomes and adverse events in real-world clinical practice.

The team asked 55 neurologists following male patients with muscular dystrophies who switched therapies, to conduct a medical chart review comparing data from before and after switching. 

The study included patients with DMD and Becker muscular dystrophy (BMD), a milder and less common form of muscular dystrophy.

Information was collected from 62 patients with DMD, who initially presented symptoms at 4.1 years (on average), had a mean age at the switch of 6.2 years, and an average prednisone treatment of 2.7 years. 

A total of 30 BMD patients were included, who first presented symptoms at 8.3 years (on average), had a mean age of 20.1 years at the switch, and an average treatment duration of 5.3 years for prednisone.

Patients had been on Emflaza for six months when the data were analyzed.

Loss of walking ability without assistance occurred in 24% of DMD patients, at a mean age of 9 years, compared to 17% of BMD participants, at a mean age of 18 years. 

The primary reason for switching therapies was a “desire to slow disease progression,” in 83% of DMD and 79% of BMD participants, followed by “tolerability issues” reported by 67% with DMD and 47% with BMD. Other reasons included a preference or request by a parent, caregiver, or patient. 

Switching was reported to be “somewhat” or “very” effective at addressing these primary reasons in 95% of patients with DMD, and 90% of those with BMD. 

Clinical Global Impression of Improvement scores were compared between 23 DMD patients treated with prednisone and 22 treated with Emflaza for three months or more. During treatment, most patients’ disease progression stabilized or eased, with a shift toward clinical improvement after the switch. 

On Emflaza, 36.4% of participants had “minimally improved,” 9.1% had “much improved,” and 18.2% had “very much improved.” In contrast, for patients who received prednisone, 8.7% had “minimally improved,” 4.3% had “much improved,” and none said they were “very much improved.” A similar pattern was seen in those with BMD. 

Commonly reported adverse events during prednisone and Emflaza treatment included weight gain, followed by facial puffiness, central obesity, increased appetite, and fluid retention. The occurrence of adverse events was lower with Emflaza. 

“In this real-world retrospective chart review of patients with DMD or BMD who switched to deflazacort from prednisone, the majority of physicians’ primary reason in switching aimed to improve benefit-risk and delay disease progression,” the team wrote. “During the 6-months average follow-up after switching, physician-reported outcomes were consistent with deflazacort addressing the primary reasons for switching.”

“Future real-world studies with longer follow-up times on deflazacort are needed to comprehensively characterize the impact of switching from prednisone to deflazacort,” they added. Other limitations of the present study, the investigators said, included the lack of functional measures commonly used in clinical trials across all centers.

Susan Apkon, MD, the study’s senior author at Children’s Hospital of Colorado, said: “Results from the real-world chart review presented today support the potential of EMFLAZA to alter the natural history of Duchenne muscular dystrophy, demonstrating its capability to slow progression of the disease and improve benefit-risk.”

“We believe that EMFLAZA will continue to provide DMD patients a safe and effective treatment option,” Apkon added.