Use of Lower-Than-Recommended Doses of Immune Checkpoint Inhibitors in Various Tumor Types: Indian Study
In an Indian single-institution study reported in JCO Global Oncology, Patel et al found that use of lower-than-recommended doses of immune checkpoint inhibitors showed activity across various tumor types.
As stated by the investigators: “The cost of immune checkpoint inhibitors limits their accessibility to a small number of patients with cancer in low- and middle-income countries. Early-phase clinical trials have shown target inhibition and high activity at doses lower than those registered and evaluated in clinical trials. Here, we report everyday experience of using immune checkpoint inhibitors in 100 Indian patients, many of whom received lower doses of immune checkpoint inhibitors.”
The study recruited 100 consecutive patients who received at least one dose of an immune checkpoint inhibitor irrespective of tumor type at a tertiary care hospital in Mumbai, India. The primary outcome measure was objective response. Among the 100 patients, 25 received conventional immune checkpoint inhibitor doses, 29 received lower doses on the basis of body weight, and 46 received low-dose treatment.
Immune checkpoint inhibitors were used as a single agent in 21 patients (5 in adjuvant and 16 in palliative settings). The remaining patients received either concurrent tyrosine kinase inhibitors or chemotherapy.
Overall, the median number of immune checkpoint inhibitor cycles received was five (range = 1–28). Response evaluation was available for 93 patients.
Adoption of per-body weight and lower dosing of immune checkpoint inhibitors appears to give acceptable outcomes. Lower dosing can improve access and timely delivery of immune checkpoint inhibitors in low- and middle-income countries.— Patel et al
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Overall, 78 evaluable patients received immune checkpoint inhibitors in a palliative setting. Objective responses were observed in 28 of 37 patients (76%) receiving low-dose immune checkpoint inhibitors, 14 of 23 patients (61%) receiving low-dose per body weight dosing, and 13 of 18 patients (72%) receiving fixed approved immune checkpoint inhibitor dosing. Over 3 years of the study, there was a trend toward increased use of lower doses. Median overall survival among patients treated in the palliative setting was 6.8 months (range = 4.6–9.0 months).
Among patients receiving neoadjuvant treatment, objective response was observed in two of three patients with breast cancer with low-dose treatment and in three of three patients with head and neck cancer with combination treatment including low-dose immune checkpoint inhibition.
As stated by the investigators: “The objective response rate did not differ statistically among different dosing groups, but comparisons are confounded by inclusion of different immune checkpoint inhibitors, different tumor sites, and concurrent treatments. Adoption of per-body weight and lower dosing of immune checkpoint inhibitors appears to give acceptable outcomes. Lower dosing can improve access and timely delivery of immune checkpoint inhibitors in low- and middle-income countries.”
Amol Patel, MD, DM, MBBS, of the Department of Medical Oncology, Indian Naval Hospital Ship, Asvini, Mumbai, is the corresponding author of the JCO Global Oncology article.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.