Chemotherapy for non-Hodgkin's lymphomas is highly effective for most patients.
In aggressive lymphomas, such as diffuse large B-cell lymphoma (DLBCL), first-line chemotherapy cures most patients.
In indolent lymphomas, such as follicular lymphoma (FL), first-line chemotherapy induces a remission in most patients.
However, once drug resistance occurs ("refractory"), the prognosis sharply becomes poor.
All novel agents must overcome this drug resistance and have an adequate safety profile.
Hu5F9 is an antibody that targets CD47, which is one of the body's normal defences against being eaten by the immune system ("phagocytosis").
Lymphoma cells often use CD47 to avoid being eaten themselves.
If one blocks CD47, the "don't eat me" signal is removed and the normal immune system is allowed to eat the lymphoma cells.
This strategy works best when combined with rituximab because it places an "eat me" signal on the lymphoma cells to avoid effects on most normal cells.
Hu5F9 Rituximab has been shown to work in drug-resistant lymphoma, but the number of cases was limited and the durability of the effects were unknown.
Researches believe that this study enhances our understanding of the effect in a larger number of patients.
The results of this study were presented at the 2019 European Hematology Association (EHA) Annual Meeting.
They report that the durability of responses is promising and the long-term safety is excellent; almost all side effects occur in the first cycle.
They believe that future studies will need to build on these findings and determine if this is better than alternatives.
Since the safety profile is excellent, it is possible to use such therapy in almost all patients, and additional agents can likely be safely added to further improve efficacy.