The Roy Castle Lung Cancer Foundation
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Pembrolizumab; Any success stories being only 20% positive for the mutation?

My husband hasn't had the go ahead yet for this line of treatment but we are not holding our breath either. So far he is getting no treatment at all as the chemo therapy didn't work.

Did anyone have Pembrolizumab being only 20% positive for the mutation and how is the outcome please please help me.

Thank you


1 Reply

Dear Ntu21

Welcome to the forum and sorry to hear about your Husband illness , please accept our apologies for the delay in replying to you.

The Pembrolizumab (immunotherapy) is used as second or third line treatment and usually after chemotherapy if it has not worked.

I have put some figures below to explain what I think you may be talking about on the 20% positive for the mutation. The pathology from the biopsy would look at the PD-L1 (which is a protein in the cell), if this shows to be positive >50% then Pembrolizumab could be used as a first choice treatment, but which also would show the protein is at a higher range.

However if the PD-L1 shows >1% then this immunotherapy could be given after chemotherapy. I have placed the guidelines on this which explains this well below.

This is another link which is in much more detail on the pathologist view on the PD-L1 and the two ranges that the approved guidelines from the FDA (Food and Drug Administration)

Everyone is different in their response to any form of treatment, but it is always encouraging to hear positive real life stories. There are a selection of these inspiring accounts in our Roy Castle Inspire magazines. I have placed the link below.

If you wish to discuss anything you can call us on our free nurse led helpline number on 0800 358 7200

All the best

The Roy Castle Support Team


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