Discontinuing Ineffective Immunotherapy May Reduce Cancer Survival Rate

Study finds halting immunotherapy after disease progression in head and neck cancer may not be the best strategy.

Immunotherapy has gained popularity in treating multiple different types and subtypes of cancer. The targeted nature of these drugs increases immune system action against cancer cells, while leaving healthy cells unaffected.

Although immunotherapy has transformed the oncology world, the drugs may not be effective in certain cases. Traditionally, when cancer progresses, the physician will discontinue treatment and prescribe a different therapy. New findings indicate that this may not be the most effective approach in treating patients with head and neck cancers.

Some patients with head and neck cancers may gain additional benefits from continuing immunotherapy even after tumors have progressed, according to a study presented at the American Association for Cancer Research annual meeting.

Findings from the phase 3 clinical trial are the first that explored the effects from continued use of an immunotherapy drug, which showed that it improved survival among patients with head and neck cancer whose tumors grew.

The study included 139 patients with recurrent or metastatic squamous cell cancer of the head and neck that progressed after treatment with nivolumab (Opdivo). The PD-1 inhibitor works by stopping PD-1 from preventing immune system attacks on tumor cells.

If a patient was doing clinically well and were strong enough to endure additional treatment, they were allowed to continue nivolumab treatment, according to the study. Other patients were able to discontinue treatment.

The study authors discovered that the 57 patients who continued therapy had a median survival of 12.7 months, and the 82 patients who stopped treatment had a median survival of 6.1 months.

Interestingly, patients who continued treatment experienced tumor shrinkage up to 30%, despite initial progression on the drug.

These findings suggest that if clinically appropriate, patients with head and neck cancers should consider continuing immunotherapy, regardless of initial progression. Additional studies are needed to determine if this is the right approach for all patients with head and neck cancers or if it can be effective in cancers.

“The benefit is often seen with increased survival, not necessarily tumor shrinkage a response rate,” said study lead author Robert Haddad, MD. “Our findings suggest that for patients with head and neck cancer who are doing well enough, continuing nivolumab therapy after disease progression can often lengthen survival. For such patients, it can be a mistake to give up on these drugs too early, and clinical judgment should be exercised to determine whether it would be beneficial to continue therapy.”