Why did stage 4 ALK cancer not respond to immunotherapy?

Question

Hello doctor,

My brother is 38 and has stage 4 ALK-positive lung cancer. Initially, doctors tried immunotherapy, but scans after three cycles showed progression. Later, a mutation test was done. We were confused as to why the treatment failed. We are looking for your opinions on the following:

Why did stage 4 ALK cancer not respond to immunotherapy?
Does ALK mutation make immunotherapy ineffective?
Would targeted therapy have been a better first option?
Also, does a poor response to immunotherapy mean prognosis is worse, or does switching treatment change the outlook significantly?

Kindly give your suggestions.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and understand your concern.

In ALK (anaplastic lymphoma kinase)-positive lung cancer, immunotherapy often does not work well. This is because these tumors usually have biological features (like low mutation burden) that make them less visible to the immune system.

So, disease progression after a few cycles of immunotherapy is common in ALK-positive patients and does not mean something unusual or wrong happened. The ALK mutation itself is a strong “driver” of the cancer, and treatments that directly target this mutation (ALK inhibitors) are much more effective than immunotherapy in most cases.

Because of this, targeted therapy is generally the preferred first-line treatment once ALK positivity is known. In some situations, treatment like immunotherapy or chemotherapy is started first because of the following reasons:

Mutation results like NGS (next-generation sequencing) are not yet available.
The cancer needs urgent treatment.
The ALK status was unknown initially.

Once the mutation is identified, doctors usually switch to targeted therapy, which is what should happen. Importantly, poor response to immunotherapy does not mean a worse prognosis in ALK-positive lung cancer. It is an expected behavior for this cancer subtype.

I hope you find this information helpful.

For more queries, feel free to reach out to me anytime.

Thank you.