Long‑Term Safety and Efficacy of RO7790121 in Adults with Moderate to Severe Rheumatoid Arthritis: Extension Study

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What is this study about?

People with moderate to severe Rheumatoid arthritis experience joint pain, swelling, and stiffness that can limit daily activities. The study involves a medication called Afimkibart, which is identified by the code name RO7790121, and is given as a subcutaneous injection. Some participants receive the medication while others receive a placebo, which looks the same but does not contain the active drug.

The main aim of the study is to evaluate the long‑term safety and tolerability of the medication. After a previous trial, participants may continue receiving the study drug or placebo for an extended period, with regular clinic visits where health status is checked, blood samples are taken, and any side effects are recorded.

During the study, doctors will look for improvements in joint symptoms and overall disease activity using standard assessment tools, and they will monitor laboratory results and vital signs to ensure the medication remains safe over time.

1 baseline visit

you attend the first study visit after enrollment. during this visit, a complete medical history is recorded, blood samples are taken, vital signs are measured, and disease activity is evaluated using standard rheumatoid arthritis assessments.

2 randomization

based on the study design, you are assigned to receive either the test medication (afimkibart, also called ro7790121) or a matching placebo. the assignment is done by the study staff and you are not informed of which you receive.

3 initial dosing

you receive the first dose as a subcutaneous injection (injection under the skin). the medication is supplied as a solution for injection/infusion. the exact dose and dosing schedule are defined by the trial protocol and are administered at each scheduled visit.

4 regular follow‑up visits

you return to the clinic at regular intervals defined by the protocol (for example, every 4 to 8 weeks). at each visit you:

– receive the next subcutaneous injection of afimkibart or placebo,

– undergo safety assessments, including checking for any adverse events,

– have blood drawn for laboratory tests,

– have vital signs measured, and

– have disease activity re‑evaluated.

5 ongoing treatment period

the injection schedule continues for the duration of the extension study, which may last several years until the study end date of 2033‑07‑09. you remain on the assigned treatment for the entire period unless a serious safety concern requires discontinuation.

6 final study visit

at the end of the study, you attend a final visit. comprehensive assessments are performed, including safety evaluation, laboratory testing, vital signs, and disease‑activity measurements. the final blood sample is taken to measure the serum concentration of afimkibart.

Who Can Join the Study?

  • Finished the treatment part of the earlier (parent) study.
  • Agree to follow the birth‑control contraception rules used in the trial.
  • Come back for the follow‑up visit and show at least a 20% better score on the Swollen Joint Count (SJC) and the Tender Joint Count (TJC) compared with the start of the study. (These counts measure how many joints are swollen or painful.)
  • Be an adult or older teenager as defined by the study’s age groups.
  • Be either male or female and able to give consent, even if considered a vulnerable participant.

Who Cannot Join the Study?

  • Withdrawing consent (deciding not to continue) or stopping the earlier study early means you cannot join this trial.
  • If you had to stop taking the study medicine permanently in the earlier study, you are not allowed to participate.
  • Using any prohibited therapy (a medicine or treatment that the study does not allow) during the earlier study makes you ineligible.
  • Having a new or uncontrolled concomitant disease (another health problem that is not under good control) that the doctor believes would make participation unsafe means you cannot join the trial.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name City Country Status
Katholieke Universiteit te Leuven Leuven Belgium
Oncopole Claudius Regaud Toulouse France
Fondazione Policlinico Universitario Agostino Gemelli IRCCS Rome Italy
IRCCS Humanitas Research Hospital Rozzano Italy
CENTRUM MEDYCZNE REUMA PARK Warsaw Poland
Université Libre de Bruxelles – Hôpital Erasme Brussels Belgium

Other Sites

Site Name City Country Status
Region Sjaelland Holbæk Denmark
Hopital Beaujon Clichy France
Centre Hospitalier Universitaire De Montpellier Montpellier France
Azienda Ospedaliera di Padova Padua Italy
St. Elisabeth Gruppe GmbH Katholische Kliniken Rhein-Ruhr Herne Germany
Reumatop Grzegorz Rozumek Karin Pistorius Sp. j. Wroclaw Poland
Staedtisches Klinikum Dresden Dresden Germany
Reumed Sp. z o.o. Lublin Poland
Twoja Przychodnia Nowosolskie Centrum Medyczne Sp. z o.o. Nowa Sol Poland
Malopolskie Badania Kliniczne Sp. z o.o. Cracow Poland
BIF-MED Bytom Poland
Universidade De Santiago De Compostela Santiago De Compostela Spain
Hospital General Universitario Gregorio Maranon Madrid Spain
Centrum Kliniczno-Badawcze J.Brzezicki B.Gornikiewicz-Brzezicka Lekarze sp.p. Elblag Poland
Htjdgi Hyokznlo Herlev Denmark
Agkkydhwvl Pfpaxcbg Huwwjhtl Da Molpargxf Marseille France
Aubwyzh Udn Iyfus Dk Rtaoya Ecllxe Reggio Emilia Italy
Nijiijlg Ilpvjadf Ghxbccdjy Rxtiztiqflzo I Robqpnwzgtitf Iw Pwero Do Hjbj Mnmw Eqbezpjj Rcorsgc Warsaw Poland
Hfpwotda Ubbwbuvnchbbsi Srwzbuvbdv &ahxwks Htcsffk dg Hifsoaimptt STRASBOURG, Alsace France
Hdopomlf Vniq ddhpqpjb Barcelona Spain
Hghgkivx Utejgplbsytex ds A Clkemp A Coruna Galicia Spain

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
Belgium Belgium
Not yet recruiting
05.06.2026
Denmark Denmark
Not yet recruiting
05.06.2026
France France
Not yet recruiting
05.06.2026
Germany Germany
Not yet recruiting
05.06.2026
Italy Italy
Not yet recruiting
05.06.2026
Poland Poland
Not yet recruiting
05.06.2026
Spain Spain
Not yet recruiting
05.06.2026

Trial locations

Investigated drugs:

Afimkibart (RO7790121) is an experimental medicine that is given as a subcutaneous injection, meaning it is injected just under the skin. In this study, participants with rheumatoid arthritis receive the medicine as a sterile solution that is prepared for injection. The main purpose of the trial is to watch how safe the drug is when it is taken for a long time and to see if it continues to help control the symptoms of rheumatoid arthritis. Researchers will monitor participants for any side effects and will assess how well the medicine works to reduce joint pain, swelling, and damage over an extended period.

Rheumatoid arthritis – Rheumatoid arthritis is a chronic autoimmune condition that primarily affects joints. The immune system mistakenly attacks the lining of the joints, causing inflammation. Over time the inflammation can lead to swelling, pain, and stiffness, especially in the morning. The joint damage may gradually cause loss of joint shape and reduced movement. The disease often involves multiple joints symmetrically and can spread to other tissues. Symptoms may worsen in periods called flares and improve during quieter phases.

Trial ID:
2025-523579-47-00
Protocol code:
WA46440
Trial Phase:
Therapeutic exploratory (Phase II)

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