A novel immune-based treatment developed by global healthcare company Grifols has shown significant promise in treating post-polio syndrome (PPS), a debilitating condition affecting polio survivors years after their initial infection. The phase 2/3 clinical trial demonstrated that monthly intravenous immunoglobulin (IVIG) infusions can halt and even improve declining physical function in PPS patients.
The year-long study involving 191 participants evaluated Flebogamma 5% DIF, a concentrated solution of antibodies designed to boost the immune system and reduce inflammation. Results showed statistically significant improvements in mobility and endurance compared to placebo.
"This study is great news since it proves that the ongoing decline in physical functioning due to post-polio syndrome, which was so far considered inevitable, can be halted, and even be improved," said Professor Dr. Frans Nollet from the Department of Rehabilitative Medicine at the University of Amsterdam's Academic Medical Center (AMC), one of the study's principal investigators.
Significant Mobility Improvements
The trial's primary endpoint measured performance using the two-minute walk distance (2MWD) test, an established metric for assessing strength, endurance, and mobility. Patients receiving monthly Flebogamma 5% DIF infusions walked an average of 12.75 meters (41.8 feet) farther after treatment compared to their baseline measurements. This represented a 6.07-meter (20-foot) improvement over the placebo group.
Secondary endpoints showed even more impressive results. In the six-minute walk distance (6MWD) test, IVIG-treated patients demonstrated a 29.16-meter (95.7-foot) improvement from baseline—15.8 meters (51.8 feet) better than the placebo group.
"These results show a meaningful physical accomplishment, providing patients with more freedom of movement and the ability to be more self-reliant," noted Dr. Jörg Schüttrumpf, Grifols Chief Scientific Innovation Officer.
Post-Polio Syndrome: An Underrecognized Burden
Post-polio syndrome affects between 25% and 40% of polio survivors, typically manifesting decades after the initial infection. The condition is characterized by progressive muscle weakness, fatigue, and pain in previously affected and seemingly unaffected muscles.
An estimated 12-20 million polio survivors worldwide are at risk of developing PPS. Until now, treatment options have been limited to supportive care and symptom management, with no approved medications specifically for PPS.
The condition primarily impacts the legs in most patients (95% of study participants), progressively limiting mobility and independence as patients age. This makes the demonstrated improvements in walking distance particularly meaningful for quality of life.
Treatment Safety Profile
The trial found Flebogamma 5% DIF to be safe and well-tolerated. The most common adverse reactions, reported in at least 5% of adult participants, included headache, fever, pain, infusion site reactions, diarrhea, chills, and hives—a safety profile consistent with other IVIG treatments.
Future Implications
Grifols has expressed commitment to expanding the indications for its plasma-derived medicines. The positive results from this trial represent a significant advancement for PPS patients who previously had no effective pharmacological options.
While the full trial results have not yet been peer-reviewed or published in a scientific journal, the findings offer new hope for the millions of polio survivors worldwide who face the prospect of PPS.
"That is positive for all polio survivors, who are confronted with increasing disabilities as they age and for whom no effective medication was yet available," Dr. Nollet emphasized.
The development comes at a critical time, as the global population of polio survivors continues to age, potentially increasing the prevalence of PPS in the coming years despite successful polio eradication efforts in most countries.
