On the right side of the curve…

It’s been just over two years since I started immunotherapy treatment for Stage 4 head and neck cancer, and what a roller-coaster two years it’s been. I still frequently catch myself in a surge of panic of what could have been, given the ‘you have less than a year to live’ diagnosis. Yet I had this constant refrain in my head that abandoning David was ‘intolerable', and I've lived in a bubble that it couldn’t happen anytime soon.

However, my treatment with immunotherapy has now come to an end. I’m not going to lie, coming off the treatment scared the crap out of me, and it’s taken a fair bit of time to rationalise within myself that being taken off Pembrolizumab is for the good.

There are a number of reasons why patients will be taken off an immunotherapy checkpoint inhibitor (ICI) like Pembrolizumab:

1.     They have had a bad reaction to it (technically called an immune-related adverse event (irAE), such as liver failure, kidney failure, diarrhoea, colitis, acute pancreatitis - really the list goes on and on ☹️.

2.     It’s increasingly apparent that ICIs are also associated with hyperaggressive disease progression (HDP), that is immunotherapy may actually accelerate tumour growth, leading to worse outcomes in patient health. For example for almost 30% of people with head and neck cancer, immunotherapy actually accelerated cancer progression (hyperprogression), especially in patients where the metastasis appeared elsewhere in the head and neck (see figure below).

3.     The drug no longer appears to be working, because tumours start to grow again and / spread (nondurable response (NR) progressive disease (PD))

4.     If none of the above apply, and the patient exhibits either stable disease (SD) or a durable response (DR),  i.e. shrunken tumours have kept small and show no signs of spread (see figure above), then they come up against the rule that the drug is only licensed  by NHS England for a maximum of two years.

It is clear therefore that there is a balance between being on an immunotherapy drug for a long time, and weighing up the risks that an adverse event could occur. Furthermore, these drugs are expensive and NHS budgets are tight. In the UK, Pembro treatment for 2 years would be about £180,000 per patient exc. VAT.  And just to add into the mix, treatment with immune checkpoint inhibitors in the past 3 years has had the extra risk of immunotherapy interacting with Covid-19 on immune hyperactivation.

Anyhoo, that’s some of the evidence behind some of the decisions. But what about my own case?

Well, I met with my new oncologist on Wednesday to go through my latest scans which detail the impact that immunotherapy has had on my cancer after the full two years. And pretty much the first thing he said to me was that I’ve had “an outstanding response to Pembro”. For him personally, I'm the first person he’s met who has completed the full two-year term of the drug, and I got the impression that completing the full two years was not very common!

Perhaps more importantly, the scans can no longer detect any of the tumours first detected two years ago. In the medical jargon, I’ve had a complete radiological response.

You can see the dramatic impact that immunotherapy has had, for example, on the largest tumour in my lungs, between August 2021 (image on the right before I started Pembro; tumour in the red circle) and November 2023 (image on the left after completing Pembro) – the tumour has completely disappeared.

What does this mean? A complete radiological response does not mean cure. [I’ve been here before!!] Cancer cells may still be swirling about in my body, but disease is not detectable. A complete response is the disappearance of all lesions, and is best result that can be reported, and that is good enough for me.

It still means that I will undergo scans every 3 months to monitor any future disease progression. If new tumours do appear, then a case will be made for me to go back onto Pembro, and I hope given my tolerance to the drug so far, that case will be granted.

But at the moment I’m in the here and now, I really could not have hoped for a better end to the year.