Merck's Letermovir Tablets (II) approved in China, adding a new option for CMV prevention

Merck & Co. announced its novel non-nucleoside cytomegalovirus (CMV) inhibitor Prevymis®.The new formulation of Letemovir Tablets (Ⅱ) has been approved by China's National Medical Products Administration (NMPA) for the prevention of cytomegalovirus (CMV) infection and cytomegalovirus disease in CMV-seropositive adult recipients and pediatric recipients aged 6 months and above with a body weight ≥6 kg [R+] who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT).

Hematopoietic stem cell transplantation offers hope for the cure of numerous hematological diseases, but cytomegalovirus infection and cytomegalovirus disease after transplantation can directly lead to an increase in transplant-related mortality.[1] According to statistics, there were a total of 39,918 HSCT recipients in 2022 and 2023, including 9,860 children, which means that one out of every four patients receiving hematopoietic stem cell transplantation is a child.[2] These pediatric patients may face a higher risk of CMV reactivation after transplantation.[3] 

Prevymis®(Letermovir) is the first and currently the only available CMV prevention regimen for adult and pediatric patients undergoing HSCT in China. For adult HSCT recipients and pediatric recipients aged 12 years or older with a body weight ≥30kg, letermovir has a fixed dosage regimen; for pediatric HSCT recipients under 12 years of age or those aged 12 years or older with a body weight <30kg, the dosage of letermovir needs to be adjusted between 40mg and 240mg based on body weight and concomitant use of cyclosporine.[4]

Letemovir Tablets (Ⅱ) are available in two specifications: 20mg/bag and 120mg/bag, meeting the needs of Prevymis® (Letermovir) in covering the dosage requirements for patients of all ages and weights within the indicated population. They can be administered orally mixed with soft food, or via nasogastric or gastric tube [4], effectively solving the problem of swallowing difficulties in young children.

"Children are the key protected group in public health and clinical care. Prevymis® (Letermovir) has been expanded for use in pediatric patients this year." Dr. Li Zhengqing, Senior Vice President of Merck & Co., Inc. and President of Merck China Research and Development Center said that "we are very pleased to see the approval of Letemmovir Tablets (Ⅱ), and we hope that this new formulation can build a precise protective barrier for more children with blood diseases. MSD will continue to focus on patients, providing more antiviral solutions that meet their actual needs, safeguarding the hope of children and their families."

Previously, Prevymis® (Letermovir) has been approved in China for two formulations: Letermovir tablets and Letermovir injection.

[1] Zakhour, J., Allaw, F., Haddad, S.F. et al. The Ten Most Common Questions on Cytomegalovirus Infection in Hematopoietic Stem Cell Transplant Patients. Clin Hematol Int 5, 21–28 (2023). https://doi.org/10.1007/s44228-022-00025-3

[2] Xu, LP., Lu, PH., Wu, DP. et al. Hematopoietic stem cell transplantation activity in China 2022–2023. The proportions of peripheral blood for stem cell source continue to grow: a report from the Chinese Blood and Marrow Transplantation Registry Group. Bone Marrow Transplant (2024). https://doi.org/10.1038/s41409-024-02419-8.

[3]Jin Runming, Xu Jiawei, Jiang Qiong. Advances in the Diagnosis and Treatment of Cytomegalovirus Infection After Allogeneic Hematopoietic Stem Cell Transplantation in Children [J]. Chinese Journal of Infection and Chemotherapy, July 20, 2023, Vol. 23, No. 4. 524-530.

[4]Letemovir Tablets (Ⅱ) Instructions

Source: MSD press release