Immunotherapy Among Patients with Melanoma and the Checkpoint Inhibitor Era

March 21, 2020

Researchers analyzed a patient population with stage IV melanoma and found no difference in the rate of surgical resection with the use of immunotherapy between the checkpoint inhibitor era and pre-checkpoint inhibitor era.

The distribution of immunotherapy for patients with stage IV melanoma was unequal, and the rates of surgical resection did not differ with the use of immunotherapy between the checkpoint inhibitor era and pre-checkpoint inhibitor era, according to a study released in Cancer.

More, the patients who received immunotherapy in the checkpoint inhibitor era were more likely to be younger, be healthier, have private insurance, come from upper income quartiles, and be treated at academic programs.

“Use of immunotherapy significantly varied among patients with stage IV melanoma according to age, socioeconomic status, and treating facility,” wrote the researchers. “In comparison with the pre-checkpoint inhibitor era, the difference-in-difference analysis demonstrated that the approval of immunotherapy in 2011 was not associated with an increase in surgical resection of distant metastasis for stage IV melanoma among patients who received immunotherapy.”

The researchers utilized a difference-in-difference analysis, which revealed similar rates for surgical resection of stage IV melanoma with the use of immunotherapy in both the checkpoint inhibitor era and pre-checkpoint inhibitor era, regardless of facility type.

The study incorporated 14,433 patients into its analysis, divided into the checkpoint inhibitor era and the pre-checkpoint inhibitor era. The checkpoint inhibitor era population was split, with 6329 patients not receiving immunotherapy, and 580 patients receiving immunotherapy. For the pre-checkpoint inhibitor era population, 5645 patients did not receive immunotherapy, and 1879 patients received immunotherapy.

The difference of overall survival for patients who received immunotherapy between the checkpoint inhibitor era and the pre-checkpoint inhibitor era was not statistically significant (median overall survival, 17.2 months [95% CI, 15.3-19.8 months] vs 15.8 months [95% CI, 13.7-17.9 months]; P= .62; Fig. 3). Meanwhile, the difference for patients who did not receive immunotherapy between pre-checkpoint inhibitor and checkpoint inhibitor era was statistically significant (median overall survival, 6.7 months [95% CI, 6.4-6.9 months] vs 7.1 months [95% CI, 6.7- 7.6 months]; P< .001), but not clinically significant.

“We found that use of immunotherapy is not evenly distributed across all patients with stage IV melanoma disease: It is more common among patients who are younger, are healthier, have private insurance, come from higher income quartiles, and are treated at academic programs,” wrote the researchers.

The findings from the study were reflective of the initial experience with ipilimumab, a phase III study which led to approval by the FDA in 2011. Moreover, the researchers were sure to point out that older patients and patients with Medicaid insurance were less likely to undergo resection of distant metastatic disease among patients who received immunotherapy in the checkpoint inhibitor era. 

One major limitation of the study includes the process of recruitment through the National Cancer Database. The NCDB does not allow for the researchers to gain access to a number of details regarding patients, including causation, previous operations, time between diagnosis and surgical resection, identification of specific medications, among other things.

“Use of immunotherapy in the stage IV setting may offer a more comprehensive treatment of distant metastases, and this may make surgical resection with its associated potential risks and complications less appealing,” wrote the researchers.

Reference:

Molina G, Kasumova GG, Qadan M, et al. Use of Immunotherapy and Surgery for Stage IV Melanoma. Cancer. DOI: 10.1002/cncr.32817.