Background: Switching from a reference product (RP) to a biosimilar (BS) aims to generate savings. Patient adherence after a switch is linked to overall experience that can be impacted by patient or treatment characteristics.

Objectives: This study aimed to analyse patient-experience and satisfaction after the switch from an adalimumab (ADA) RP or BS to CT-P17 ^[1] (ADA BS high concentration (HC), citrate-free).

Methods: YU-MATTER (NCT05427942), a multicentric prospective observational study included patients with chronic inflammatory rheumatic disease (CIR) or inflammatory bowel disease (IBD) treated with ADA: either the RP (HC: 100mg/ml) or a BS with low concentration (LC: 50 mg/ml). Patients were switched to CT-P17 and followed-up for 3 months (M). Clinical characteristics were collected at M0, including patient-experience via 5 self-questionnaires developed in collaboration with patient associations to explore satisfaction regarding the injection (Likert 7), discomfort (pain [NRS 0-10], redness [Likert 4], itching [NRS 0-10], and haematoma [Likert 3]). Satisfaction and overall injection tolerance (pain < 4 AND absence of redness AND itching < 4 AND absence of haematoma) were assessed between M0 (just before switch) and M3 (3 months after switch). Factors associated with satisfaction improvement (Likert) were explored through multivariable logistic regression.

Results: Of the 232 patients analysed, the rheumatology population counted 65 patients with CIR (RA=17, AS=35, nr-axSpA=7, PsA=6,). mean age was 54±9 years; median disease duration was 9 years ([Q1; Q3]: [5; 18]) and 49.2% were men. Over the analysed population, 119 (51.2 %) patients were switched from a BS (45 with citrate) and 113 (48.7%) from the RP. At 3 months, 175 patients (75.4%) were satisfied with the injection and 145 (62.5%) had a stable or improved satisfaction versus the previous ADA. Among patients receiving a BS, the presence of citrate was significantly associated with an improvement of satisfaction after switching to CT-P17 (58.3% vs. 30.0%, p=0.006). Overall injection tolerance significantly improved after switching from 28.9 % at M0 to 57.7 % at M3 (p<0.0001). A significant decrease of pain related injection was observed after the first injection of CT-P17 (median -2 [-4;-1]) for patients switched from a BS and remained stable for patients switched from the RP (median 0 [-1;1]). In multivariable analysis, the switch from a LC ADA was an independent factor of satisfaction improvement (vs from the RP, odds ratio=3.03; p=0.003; Table 1).

Conclusion: The global experience of switching to CT-P17 was positive with an overall improvement in injection tolerance. Injection volume was an independent factor associated with a successful experience.

REFERENCES: [1] Furst DE, and al. Efficacy and safety of switching from reference adalimumab to CT-P17 (100 mg/ml): 52-week randomized, double-blind study in rheumatoid arthritis. Rheumatology (Oxford). 2022.

[2] Horne R, and al. The Beliefs about Medicines Questionnaire: The Development and Evaluation of a New Method for Assessing the Cognitive Representation of Medication. Psychology & Health 1999.

Acknowledgements: We thank all patients for their active participation in the study by answering questionnaires, patient associations (AFA, ANDAR, AFS) for their contribution to the study design and e-Health Services Sanoïa for the follow-up during the study and their input to results interpretation.

Disclosure of Interests: Hubert Marotte AbbVie, Amgen, Bristol Myers Squibb, Celltrion HealthCare, Galapagos, Lilly France, Merck

Sharp & Dohme, Novartis, Nordic Pharma, Pfizer, and Sanofi Aventis, AbbVie, Amgen, Bristol Myers Squibb, Celltrion HealthCare, Galapagos, Lilly France, Merck

Sharp & Dohme, Novartis, Nordic Pharma, Pfizer, and Sanofi Aventis, Bristol Myers Squibb, Celltrion HealthCare, Galapagos, Lilly France, Novartis, Nordic Pharma, Pfizer, and

Sanofi Aventis, Laure Gossec AbbVie, Amgen, BMS, Celltrion Healthcare, Galapagos, Gilead, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB, AbbVie, Amgen, BMS, Celltrion Healthcare, Galapagos, Gilead, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB, Lilly, Pfizer, Sandoz, UCB, AbbVie, Amgen, BMS, Celltrion Healthcare, Galapagos, Gilead, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, UCB, Lilly, Pfizer, Sandoz, UCB, Vered Abitbol Pfizer, Takeda, Amgen, Mylan Viatris, Sandoz, Janssen, Fresenius, Gilead, Tillotts, Celltrion, Pfizer, Takeda, Amgen, Mylan Viatris, Sandoz, Janssen, Fresenius, Gilead, Tillotts, Celltrion, Eric Senbel Lilly, Nordic, Roche, Chugai, Novartis, Sandoz, Biogen, Fresenius Kabi, Abbvie, Amgen, Biogen, Celltrion Healthcare

, Nordic, Roche, Chugai, AbbVie, Amgen, Pfizer, Sanofi, MSD, Biogen, Janssen, Fresenius Kabi

, Nordic, Roche, Chugai, Fresenius Kabi, Celltrion Healthcare

, Guillaume Bonnaud Abbvie, Amgen, Biogen, Celltrion, Cvasthera, Ferring, Fresenius, Galapagos, Gilead, Mayoli Spindler, MSD, Janssen, Pfizer, Roche, Takeda, Tillots, Sandoz, Viatris

, Xavier Roblin Celltrion, MSD, Pfizer, Abbvie, Amgen, Biogen, Takeda, Janssen, BMS, Ferring, Tillots, Vifor

, Yoram Bouhnik Abbvie, Amgen, Biogaran, Biogen, Boehringer Ingelheim, Celltrion Healthcare, Ferring, Fresenius Kabi, Galapagos, Gilead, Hospira, Iterative Scopes, Janssen, Lilly, Mayoli Spindler, Merck, MSD, Norgine, Pfizer, Roche, Sandoz, Sanofi, Shire, Takeda, Tillotts, UCB, Viatris

, Stephane Nancey Takeda, Pfizer, MSD, Abbvie, Janssen, Tillots, HAC Pharma, Novartis, Amgen, Sanofi, Hospira, Biogen, Roche, Sandoz, Celltrion, Boerhinger Ingelheim, Nicolas Mathieu Atawao Healthcare, Celltrion, CTMA, Gilead, Janssen, Abbvie, Amgen, Biogen, Ferring, Gilead, MSD, Janssen, Pfizer, Sandoz, Takeda

, Celltrion, Mylan, Sandoz, Abbvie, Amgen, Janssen, Pfizer, Takeda

, Jérôme Filippi Abbvie, Amgen, Biogen, Celltrion, Galapagos, HAC pharma, Janssen, MSD, Pfizer, Sandoz, Takeda, Tillotts

, Lucine Vuitton: None declared, Stéphane Nahon Celltrion Healthcare, Abbvie, Fresenius, Amgen, Celltrion Healthcare, Abbvie, Fresenius, Amgen, Azeddine Dellal Celltrion Healthcare France, Fresenius Kabi, Alice DENIS Celltrion Healthcare France, Caroline HABAUZIT Celltrion Healthcare France, Salim Benkhalifa Celltrion Healthcare France, Guillaume BOUGUEN AbbVie, Takeda, MSD, Janssen, Celltrion, AbbVie, Takeda, Mylan, Pfizer, Sandoz, Amgen, Ferring, Janssen, Celltrion, AbbVie, Takeda, Fresenius, Janssen, Vifor, Sandoz.