| Monoclonal antibody | |
|---|---|
| Type | Bi-specific T-cell engager |
| Source | Humanized |
| Target | CD20,CD3 |
| Clinical data | |
| Trade names | Lunsumio |
| Other names | BTCT4465A, RG7828, mosunetuzumab-axgb |
| AHFS/Drugs.com | Monograph |
| License data | |
| Drug class | Antineoplastic |
| ATC code | |
| Legal status | |
| Legal status | |
| Identifiers | |
| CAS Number | |
| DrugBank | |
| UNII | |
| KEGG | |
| Chemical and physical data | |
| Formula | C6515H10031N1725O2025S43 |
| Molar mass | 146301.54 g·mol−1 |
Mosunetuzumab, sold under the brand nameLunsumio, is amonoclonal antibody used for the treatment offollicular lymphoma.[1][2][4] It bispecifically binds CD20 and CD3 to engage T-cells.[1][2] It was developed byGenentech.[5]
The most common adverse reactions (≥20%) includecytokine release syndrome, fatigue, rash, pyrexia, and headache.[2][3] The most common grade 3 to 4 laboratory abnormalities (≥10%) include decreased lymphocyte count, decreased phosphate, increased glucose, decreased neutrophil count, increased uric acid, decreased white blood cell count, decreased hemoglobin, and decreased platelets.[2][3]
Mosunetuzumab was approved for medical use in the European Union in June 2022,[3] and in the United States in December 2022.[2][6] The USFood and Drug Administration (FDA) considers it to be afirst-in-class medication.[7][8]
Mosunetuzumab isindicated for the treatment of adults with relapsed or refractory follicular lymphoma after two or more lines of systemic therapy.[2][3]
The prescribing information for mosunetuzumab in the US has aboxed warning for serious or life-threatening cytokine release syndrome.[2]
Mosunetuzumab-axgb was evaluated in GO29781 (NCT02500407), an open-label, multicenter, multi-cohort study.[2] The efficacy population consisted of 90 patients with relapsed or refractory FL who had received at least two prior lines of systemic therapy, including an anti-CD20 monoclonal antibody and an alkylating agent.[2]
The USFood and Drug Administration (FDA) granted the application for mosunetuzumabpriority review,breakthrough therapy, andorphan drug designations.[2]
In April 2022, theCommittee for Medicinal Products for Human Use (CHMP) of theEuropean Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a conditional marketing authorization for mosunetuzumab under the brand name Lunsumio, intended for the treatment of relapsed or refractory follicular lymphoma.[4] The applicant for this medicinal product is Roche Registration GmbH.[4] Mosunetuzumab was approved for medical use in the European Union in June 2022.[3][9]
Mosunetuzumab is theinternational nonproprietary name (INN).[10]
In July 2025,Roche withdrew Lunsumio from the Swiss market following failed price negotiations with theSwiss Federal Office of Public Health (BAG).[11] The drug had been available since February 2023 through a special "Early Access" program that allowed reimbursement before complete clinical data was available. Under this arrangement, Roche initially covered treatment costs until efficacy was demonstrated, after which the remaining therapy could exceed 100,000 Swiss francs.[11][12][13][14]
WhenSwissmedic extended the temporary authorization in February 2025 due to still-missing clinical data, Roche rejected the previously negotiated pricing model and demanded higher prices.[11] The BAG refused to modify the agreement, citing concerns that exceptions would set a precedent for other pharmaceutical companies. The withdrawal was announced to oncologists on July 1, 2025, with Roche also refusing to provide individual case reimbursements—a standard Swiss mechanism for exceptional medical situations. Instead, the company offered to provide the medication free through its patient access program for hardship cases. Oncologists criticized the decision as unprecedented, while some experts suggested the withdrawal reflected broader pressures from potential U.S. pricing reforms that could affect Roche's largest market.[11][12][13][14]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
