Rituximab (MabThera): — What You Need to Know

Rituximab is not chemotherapy. It is a targeted antibody that works differently — it binds to a specific protein on B-cells rather than damaging all rapidly dividing cells. This is why most side effects closely associated with chemotherapy, such as significant hair loss and severe nausea, are not caused by rituximab itself. When rituximab is given alongside chemotherapy drugs (as in regimens like R-CHOP), side effects from both treatments occur together, but they come from different mechanisms. Your team can tell you which effects to expect from which part of your regimen.

Rituximab alone does not cause significant hair loss. Hair loss is a side effect of chemotherapy drugs, not of rituximab itself. If you are receiving a combination regimen, ask your oncologist which specific drugs in your plan are likely to affect your hair, so you can plan ahead. Some chemotherapy combinations cause partial thinning rather than complete loss, and this also depends on the drugs involved.

MabThera is the original brand name for rituximab, made by Roche. Ristova and other products are biosimilars — versions approved by national regulatory authorities after review, intended for the same uses as the original. They contain the same active molecule. Biological medicines are complex enough that each biosimilar undergoes its own approval process rather than a simple generic pathway. Your oncologist and hospital pharmacy will decide which version you receive based on availability and your specific situation.

Response is assessed through blood tests and imaging scans, typically at the end of a set number of cycles. For lymphomas, a PET-CT scan is commonly used to check whether the cancer has responded. Your oncologist will tell you when these are planned and what a good result looks like. How you feel is not a reliable guide on its own — some patients feel better before a confirmed response appears on imaging, and some feel much the same even when the cancer is responding well.

Live vaccines — such as BCG, MMR, yellow fever and oral polio — are generally not given during treatment or for a period afterwards, because the depleted immune system may not respond safely. Inactivated vaccines such as influenza injections may be recommended, but timing matters — your team will advise when your immune system is likely to respond adequately. Tell your oncologist about any vaccinations you are due before starting treatment, so the schedule can be planned around your cycles.

Rituximab's effects on B-cells persist for months after the last infusion, and B-cell recovery is gradual. The length of time varies between individuals, and your team will monitor your blood counts to track recovery. This is why infection vigilance remains important after treatment ends, not just during it. A fever in the months following your last infusion is still a reason to contact your team promptly rather than waiting to see if it settles on its own.