SB12 Equivalent to Soliris in Phase 1 Trial
Samsung Bioepis announced that its product SB12, a proposed biosimilar — a product that is highly similar, with no clinically meaningful differences, to an original patented product — to Soliris (eculizumab), showed equivalent properties with regards to the therapy’s safety, pharmacokinetics, and immune profile in a Phase 1 trial in healthy volunteers.
Pharmacokinetics refers to the movement of the therapy into, through, and out of the body.
Soliris is an approved treatment for atypical hemolytic uremic syndrome (aHUS), among other conditions, and SB12 may make treatment more affordable and accessible for patients with this disorder.
“We are excited to share the Phase 1 clinical results of our first hematology biosimilar with the medical society. Biosimilars have much potential to bring benefits to patients,” Dong-hoon Shin, vice president and medical and lifecycle team leader at Samsung Bioepis, said in a press release. Shin said that “patients with rare diseases often have limited access to treatments due to high cost of medicines.”
The results were presented at the annual meeting of the American Society of Hematology on Dec. 11 in the poster “A Randomized, Double-Blind, Single-Dose Phase 1 Comparative Pharmacokinetic Study Comparing SB12 (Eculizumab Biosimilar) with Reference Eculizumab in Healthy Volunteers.”
AHUS is a disease in which the complement cascade — a part of the immune system — is dysfunctional, causing blood clots to form in small blood vessels, leading to organ damage, especially in the kidneys.
SB12, as well as the original Soliris, are antibodies against the C5 complement protein — a part of the complement cascade. They work by preventing C5 from being cleaved into two parts, the proinflammatory C5a and C5b. Normally, C5b combines with other proteins to form the C5b-9 complex, which promotes clotting in blood vessels by bringing together platelets. When C5 cleavage is prevented, the C5b-9 complex can no longer form.
SB12 is being tested in a double-blind Phase 1 trial (NCT03722329), in which 240 healthy volunteers ages 18–55 were given a 300 milligram (mg) dose of either SB12, European Union (EU)-sourced Soliris, or U.S.-sourced Soliris via intravenous (IV) infusion for 35 minutes.
The study was designed to evaluate potential similarities and differences among the therapies. Blood samples were taken over the course of 64 days.
All comparisons, particularly regarding pharmacokinetics measurements, were contained within the bioequivalence margins of 80–125%, indicative that SB12 is bioequivalent to both the EU- and U.S.-sourced eculizumab.
The data also showed that the average complement activity and change from baseline (study start) were similar between SB12 and both the EU- and U.S.-sourced Soliris. Complement activity at the end of the infusion showed a rapid decrease and then a slow restoration of activity. Everyone responded in terms of measured complement activity following treatment.
Safety profiles, including the type of immune response that the treatment infusions generated, were also comparable across the three treatment groups. There were no deaths or discontinuation due to side effects during the study. There were two serious adverse events — one related to kidney pain when stones blocked part of the urine duct in one person in the SB12 group, and one of back pain in the U.S. Soliris group — but they were both determined to be unrelated to the treatments.
No significant difference in the anti-drug antibodies — antibodies against the treatments — were reported among treatment groups. And none of the subjects with post-infusion anti-drug antibodies against eculizumab had antibodies that neutralized the treatment’s effects.
In conclusion, this Phase 1 study “demonstrated [pharmacokinetics] bioequivalence and showed comparable [pharmacodynamics, or the effects of a therapy on the body], safety, immunogenicity [ability of cells to provoke an immune response] between SB12 and the RP [reference product] eculizumab,” the researchers wrote.
“We will continue to advance our clinical development efforts to demonstrate biosimilarity and quality of our eculizumab biosimilar through Phase 3 study, and advance our innovative development platform to bring affordable, additional treatment options for patients who don’t have access to medicines,” Shin said.