Publication of clinical trial results

The information given below and the relevant links to the clinical data fulfil the requirements of Articles 71-73 of the Ordinance on Therapeutic Products (Therapeutic Products Ordinance, TPO). They supplement the information published in association with the Swiss Marketing Authorisation for the medicinal product.

ENFLONSIA®

ENFLONSIA^® (clesrovimab), solution for intramuscular injection in pre-filled syringe.
Each pre-filled syringe contains 105 mg of clesrovimab in 0.7 mL.

Authorisation number: 70145 (Swissmedic)

Date of Marketing Authorisation: 22-Jan-2026

Clinical Studies

Protocol MK-1654-004

Study Details | NCT04767373 | Efficacy and Safety of Clesrovimab (MK-1654) in Infants (MK-1654-004) | ClinicalTrials.gov
NCT04767373

Publication:
Zar HJ, Simões EAF, Madhi SA, Ramilo O, Senders SD, Shepard JS, Laoprasopwattana K, Piedrahita J, Novoa JM, Vargas SL, Dionne M, Jackowska T, Liu E, Ishihara Y, Ikeda K, Zhang Y, Railkar RA, Lutkiewicz J, Vora KA, Zang X, Maas BM, Lee AW, Guerra A, Sinha A; CLEVER (MK-1654-004) Study Group. Clesrovimab for Prevention of RSV Disease in Healthy Infants. N Engl J Med. 2025 Oct 2;393(13):1292-1303. doi: 10.1056/NEJMoa2502984. Epub 2025 Sep 17.

Protocol MK-1654-007

Study Details | NCT04938830 | Clesrovimab (MK-1654) in Infants and Children at Increased Risk for Severe Respiratory Syncytial Virus (RSV) Disease (MK-1654-007) | ClinicalTrials.gov
NCT04767373

Publication:
Zar HJ, Bont LJ, Manzoni P, Muñoz FM, Ramilo O, Chen PY, Novoa JM, Ordoñez GA, Tsolia M, Tapiéro B, Acuña-Ávila MI, Castellanos JM, Meyer M, Morioka I, Chen Z, Railkar RA, Zang X, Maas BM, Likos A, Lee AW, Castagnini LA, Sinha A; SMART (MK-1654-007) Study Group. Clesrovimab in Infants and Children at Increased Risk for Severe RSV Disease. N Engl J Med. 2025 Oct 2;393(13):1343-1345. doi: 10.1056/NEJMc2506107. Epub 2025 Sep 17.

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