Hansa Biopharma's imlifidase is demonstrating potential in treating Guillain-Barré Syndrome (GBS) and expanding access to gene therapy for Crigler-Najjar syndrome. Recent data from a Phase 2 study and an indirect treatment comparison suggest that imlifidase, when combined with intravenous immunoglobulin (IVIg), can significantly improve motor function and accelerate recovery in GBS patients. Additionally, Hansa Biopharma and Genethon have initiated a Phase 2 trial to evaluate imlifidase as a pretreatment to gene therapy for Crigler-Najjar syndrome, potentially overcoming limitations posed by pre-existing antibodies.
Imlifidase in Guillain-Barré Syndrome
The Phase 2 study (15-HMedldeS-09) of imlifidase in GBS, a rare autoimmune disorder affecting the peripheral nervous system, showed promising results. Patients treated with a single dose of imlifidase (0.25 mg/kg) alongside IVIg exhibited rapid improvements in muscle strength and a faster return to independent walking. The median time to independently walk, defined by a GBS Disability Scale (DS) score of 2 or less, was 16 days.
In the efficacy analysis, which included 27 confirmed GBS cases, 37% of patients were able to walk independently after one week of treatment. The mean improvement in muscle strength, assessed by the Medical Research Council sum score, was 10.7 points. Furthermore, patients demonstrated a median improvement of at least one grade on the GBS DS in six days, with 67% walking independently and 40.7% regaining the ability to run by eight weeks. At six months, 63% of patients could run or had no functional disability (GBS DS ≤1).
An indirect treatment comparison analysis, pitting data from the 15-HMedIdeS-09 study against data from the International Guillain-Barré Syndrome Outcome Study (IGOS), further highlighted the potential benefits of imlifidase. The analysis included 27 participants from the 15-HMedIdeS-09 study treated with imlifidase and IVIg and 754 patients with severe GBS treated with IVIg alone from IGOS. Results indicated that patients in the combined treatment group experienced significantly faster improvement in disability, as measured by the GBS DS.
Specifically, those on the combination approach improved by at least one step on the GBS DS three weeks sooner (P = .002) and returned to independently walking six weeks sooner (P = .03) than the IGOS comparator group. The combination group was also 6.4 times more likely (95% CI, 2.3-17.5; P <.0001) to walk independently at one week and 4.2 times more likely (95% CI, 1.6-11.5; P = .005) at four weeks.
Expanding Gene Therapy Access in Crigler-Najjar Syndrome
Hansa Biopharma and Genethon have also initiated a Phase 2 clinical trial (GNT-018-IDES; NCT06518005) evaluating imlifidase as a pretreatment for Genethon’s GNT-0003, an investigational adeno-associated virus serotype 8 (AAV8) vector-based gene therapy for severe Crigler-Najjar syndrome. The single-arm study will enroll three adult patients with preformed anti-AAV8 antibodies who require at least six hours of phototherapy per day.
Imlifidase functions by cleaving IgG antibodies, inhibiting their activity and potentially allowing treatment with AAV8 vector-based gene therapy in patients who would otherwise be ineligible due to pre-existing antibodies. Soren Tulstrup, MSc, the president and CEO of Hansa Biopharma, noted that anti-AAV antibodies prevent up to one in three people from benefiting from gene therapies using AAV vectors.
Imlifidase in Anti-GBM Disease
Hansa Biopharma has completed enrollment in the GOOD-IDES-02 trial, a global pivotal Phase 3 trial in anti-glomerular basement membrane (anti-GBM) disease. Anti-GBM is a rare, severe autoimmune condition affecting approximately 1.6 people per million annually. The trial is designed to assess the superior effect on kidney function of imlifidase in combination with standard of care versus standard of care alone in patients affected by severe anti-GBM disease. Data from the trial is expected to be shared in 2025.
These developments underscore the potential of imlifidase in addressing unmet needs in IgG-mediated autoimmune diseases and expanding the applicability of gene therapies.
