Alvotech Germany GmbH

Immunogenicity against biologic medicines is ubiquitous, and it is traditionally measured by the final humoral response. However, the onset of a sustained immunogenic response begins at the cellular level with activation of T cells and maturation of naïve B cells into plasma cells. Ex vivo comparative immunogenicity assessment (EVCIA) of cellular immunogenicity in participants with moderate-to-severe chronic plaque psoriasis in the AVT02-GL-302 study, who received either reference product (RP) alone (non-switching arm) or switched between RP and AVT02 (switching arm) after 1:1 randomization at week 12. Peripheral blood mononuclear cells (PBMCs) were collected and cryopreserved from 28 participants at: baseline (before treatment) (week 1); pre-randomization (week 12); and week 16 and week 28 in both switching and non-switching arms. PBMCs were thawed and re-exposed to either medium alone (negative control), RP, AVT02, keyhole limpet hemocyanin (KLH) (positive control), RP+KLH, or AVT02+KLH. Samples from 10 participants (predetermined average cell viability of 75% across all timepoints) from each arm were analyzed for cytokine release after 24 hours and for Th-cell proliferation, 6 days post-seeding. Until week 28, cytokine release and Th-cell proliferation was similar at all time points in both switching and non-switching arms. Overall cellular immune response was elevated post-KLH re-exposure at all timepoints. The comparable ex vivo cellular immunogenicity between switching and non-switching arms complements the confirmation of interchangeability in the main study. Given the sensitivity of novel EVCIA, detecting cellular immunogenicity could be a potential outcome in predicting the immunogenicity of biologic medicines.

The development of a biosimilar is based on comparative structural, physicochemical, functional and clinical assessments. The sum of these analyses encompasses the ‘totality of evidence’, which demonstrates no clinically meaningful differences between the biosimilar and the reference product (RP). Once biosimilarity has been established, provided there is suitable scientific justification, clinical data may be extrapolated to other indications of the RP. AVT02 has been developed as a biosimilar to high-concentration, low-volume Humira (adalimumab), an anti-tumour necrosis factor-alpha monoclonal antibody approved for various chronic inflammatory indications. The totality of evidence for AVT02 is described, supporting its approval as an adalimumab biosimilar for all approved indications globally. Analytical similarity assessments using mass spectrometry methods demonstrated identical amino acid sequences for AVT02 and the RP, with high similarity in terms of primary structure, post-translational modifications and higher-order structural attributes. The mechanism of action was assessed by various cell-based potency assays and binding assays, and the results demonstrated that AVT02 is highly similar to the RP. No clinically meaningful differences in terms of purity, potency and safety were observed, and minor differences in a few physiochemical attributes did not impact the in vitro biologic activity and were not considered clinically relevant. Clinical similarity was demonstrated by comparing the pharmacokinetic, efficacy, safety and immunogenicity profiles of AVT02 with those of the RP. Clinical studies supported similar pharmacokinetic and comparable immunogenicity profiles between AVT02 and the RP in healthy participants and participants with moderate-to-severe chronic plaque psoriasis, with no new safety signals detected. The totality of evidence described demonstrates the biosimilarity of AVT02 to the RP, thereby fulfilling the scientific and regulatory requirements for AVT02 as a high-concentration biosimilar for the treatment of chronic plaque psoriasis and all approved indications of the RP.

This study compared efficacy, safety, tolerability, pharmacokinetics (PK), and immunogenicity between AVT04 and reference product (RP) ustekinumab (Stelara®) in patients with moderate-to-severe chronic plaque psoriasis (PsO).

This multicenter, double-blind, 52-week study randomized patients in 1:2 ratio to AVT04 or RP. At week 16, responsive patients (≥50% improvement in psoriasis area and severity index (PASI)) previously on AVT04 continued on AVT04, while those on RP were re-randomized 1:1 to switch to AVT04 or stay on RP. The primary endpoint was a percent improvement in PASI from baseline to week 12. Therapeutic equivalence was demonstrated if the confidence interval (CI) for the adjusted difference in means was contained within the equivalence margins; ±10% (90%CI).

Of the 581 patients initially randomized (AVT04:RP, 194:387), 575 completed week 16 and 544 completed end of study visit. The percent PASI improvement for AVT04 vs RP was 87.3% vs 86.8% (CI: -2.14%, 3.01%); study met its primary endpoint. Efficacy, safety and PK profiles were comparable across treatment arms throughout the entire study duration, and the incidence of antibodies to ustekinumab had no clinically meaningful impact.

This study demonstrates the therapeutic equivalence between AVT04 and RP in patients with moderate-to-severe chronic PsO, with similar safety and tolerability.

NCT04930042; EudraCT Number: 2020-004,493-22.