How long does it take to work and how do you know if it's working?

Official answer

by Drugs.com

Opdivo (nivolumab) is a monoclonal antibody or type of immunotherapy used to treat a number of different types of cancer. Opdivo is a programmed death-1 (PD-1) inhibitor that helps the T cells of your immune system identify and attack cancer cells. It does this by helping to block the cancer cell’s ability to disguise itself and evade detection by the immune system.

Opdivo is administered via a 30-60 minute intravenous infusion every 2-4 or 6 weeks.

How long does Opdivo take to work?

Immunotherapy works differently to traditional chemotherapeutics and can take longer to work because once Opdivo starts helping the immune system to uncover the cancer cells, it takes time for the immune system to identify and attack them.

During clinical trials of Opdivo researchers measure the ‘time to response’, which provides a time frame in which you’d expect to see a patient’s cancer show signs that it is responding to treatment and Opdivo is starting to work.

‘Time to response’ is the time taken from the day a patient is assigned to receive a particular therapy until the first day that the patient has a partial or complete response to the treatment. The ‘time to response’ observed in a number of clinical trials used to gain approval of Opdivo are reported in the table below.

Time to response following treatment with Opdivo

How do you know if Opdivo is working?

To tell if you’re responding to treatment with Opdivo your doctor will order periodic tests, such as CT (computed tomography) and PET (positron emission tomography) scans and MRI (magnetic resonance imaging). These tests help work out whether the size of your tumors is changing or new tumors have appeared.

It’s important to note that sometimes with immunotherapy treatments like Opdivo, it can initially look like your cancer is progressing even though it is getting better. This is called 'pseudoprogression' and results in a short-term increase in the size of a tumor, or the appearance of a new tumor, followed by delayed tumor shrinkage.