The European Commission ( EC ) has granted conditional marketing authorisation for the CD20xCD3 T-cell engaging bispecific antibody Lunsumio ( Mosunetuzumab ), for the treatment of adult patients with relapsed or refractory ( R/R ) follicular lymphoma ( FL ) who have received at least two prior systemic therapies.
Conditional approval is granted to a medicinal product that fulfils an unmet medical need where the benefit of immediate availability outweighs the risk of less comprehensive data than normally required.
The approval is based on positive results from the phase I/II GO29781 study where Mosunetuzumab has demonstrated high complete response rates, with the majority of complete responders maintaining responses for at least 18 months, and favourable tolerability in people with heavily pre-treated follicular lymphoma.
After a median follow-up of 18.3 months, the median duration of response among responders was 22.8 months ( 95% CI: 9.7-not estimable ), the complete response rate was 60% ( n=54/90 ), the objective response rate was 80% ( n=72/90 ).
The most common adverse event was cytokine release syndrome ( 39% ), which was generally low grade ( grade 2: 14% ), and resolved by the end of treatment.
Other common ( 20% or more ) adverse effects were: neutropenia, pyrexia, hypophosphatemia and headache.
The initial dose was administered without mandatory hospitalisation.
Mosunetuzumab is a first-in-class CD20xCD3 T-cell engaging bispecific antibody designed to target CD20 on the surface of B-cells and CD3 on the surface of T-cells.
This dual targeting activates and redirects a patient’s existing T-cells to engage and eliminate target B-cells by releasing cytotoxic proteins into the B-cells.
The GO29781 study is a phase I/II, multicentre, open-label, dose-escalation and expansion study evaluating the safety, efficacy and pharmacokinetics of Mosunetuzumab in people with relapsed or refractory B-cell non-Hodgkin lymphoma.
Outcome measures include complete response rate ( best response ) by independent review facility ( primary endpoint ), objective response rate, duration of response, progression-free survival, safety, and tolerability ( secondary endpoints ).
Follicular lymphoma is the most common indolent form of non-Hodgkin lymphoma, accounting for about one in five cases of NHL. It is considered incurable and relapse is common.
It is estimated that more than 100,000 people are diagnosed with follicular lymphoma each year worldwide, including over 28,000 people in Europe. ( Xagena )
Source: Roche, 2022