The short answer is:-

because the combination is very powerful but also very toxic, so it’s given as a short “induction” phase, then continued with nivolumab alone as a safer long-term treatment.

When I was told that I had to start IPINIVO after my melanoma decided to make an unwanted resurgence my oncologist told me that she only expected my body to tolerate 2 doses of the highly toxic combination.

Four years ago after an operation to remove the majority of my pancreas and my spleen I was given Nivolumab for 12 months. This caused quite severe side effects – especially colitis and prostatitis.

Here’s the fuller explanation:

1. Ipi + Nivo together = very strong immune activation

Ipilimumab (ipi) and nivolumab (nivo) both release different “brakes” on your immune system. Together, they supercharge your immune response against cancer. This combo gives higher response rates and deeper, longer-lasting remissions in advanced melanoma than either drug alone.

But…

2. The side effects rise sharply with combination therapy

When given together, the risk of serious immune-related side effects is much higher:

Colitis Hepatitis Thyroid/adrenal problems Lung inflammation Skin reactions Neurological issues

In trials:

Around 55–60% of patients on ipi-nivo get severe (grade 3/4) side effects. Many people cannot tolerate long-term ipilimumab.

So ipilimumab is used like a booster rather than a long-term drug.

3. The 4-dose schedule is based on survival data

The standard regimen comes from large clinical trials (like CheckMate-067):

4 doses of ipi + nivo every 3 weeks ⬇ Then nivolumab alone as maintenance

This schedule was found to:

✅ Maximise tumour response

✅ Give durable remissions

✅ Limit long-term toxicity

✅ Improve overall survival

Giving more ipilimumab did not improve outcomes but did increase harm.

4. Think of it like this:

Ipi-nivo = the shock-and-awe phase Nivo alone = long-term control and stability

Once your immune system has been properly “trained” to recognise the cancer, nivolumab keeps it active without overwhelming your body.

5. Important: Many people don’t even get all 4 doses

Because of side effects, some people only manage:

1 dose, 2 doses or 3 doses

And guess what?

They can still get excellent, long-lasting responses.

So if someone doesn’t complete all 4, it doesn’t mean the treatment has failed.

I’m really hoping to manage all 4 of the doses. The 2nd dose was postponed due to skin rashes which was managed by a quick dose of steroids (Prednisone) and then my 2nd dose was administered on December 31st.

Dose 3 – January 21st.

Here’s Hoping 🤞.