61P Immune check point inhibitors (ICIs) in cancer therapy: An experience from a resource poor and developing country

Abstract

After pioneering work on anti-tumour immunity by Nobel laureates on anti -tumour immunity and Immune Check Point Inhibitors (ICIs) the spectrum of immunotherapeutic options has increased beyond Melanoma/Renal cell carcinoma. There is paucity of data in Indian experience and hence we evaluated the efficacy of ICIs at our institute. All the patients with advanced solid cancers, who are receiving ICIs after the failure of chemotherapy at our institute, were retrospectively assessed for Patient characteristics, Clinical Benefit Rate (CBR), and Progression free survival (PFS). Response assessment was done after 3 cycles using imRECIST (Immune-modified Response Criteria in Solid Tumours). Therapy was continued until progression or unacceptable toxicity. Total 28 patients took ICIs and 19 were eligible for the evaluation. Head & Neck cancer (37%) was the most common malignancy followed by Lung carcinoma (28%), Ca Esophagus, HCC, RCC, Ca Bladder, Mesothelioma, Colon, Penis & IHCC. Majority received ICI as 2nd line therapy (47%). Nivolumab, Pembrolizumab and Atezolizumab were used in 22, 4 and 2 patients respectively. Heavily pre-treated patients who were started on ICI as 5th line therapy had a CBR of 75% f/b 15% & 44% in 3rd and 4th line treated patients. CBR was seen is 31.5% of patients. Two patients have had maximum CBR. Grade 3 adverse events (IRAE) were seen in 3 patients (11.5%) who responded to prednisolone. With a maximum follow up of a period of 9.6 months the PFS is 4.5 months. ICIs are new armamentarium in cancer treatment & major drawback in our country is the high cost which makes its usage in clinical setting a practical challenge. A comparable CBR (31.5%) was seen in our study as compared with 14-40% in international studies with two patients having a durable response. As ICI are not immune to adverse events and with good clinical judgement we can detect them with high index of suspicion. We should be cautious and intelligent enough to detect IRAEs with high index of suspicion and pre-therapy work up as early as possible and we should report the same. Major drawback of usage of ICI in our country is the high cost of drug which makes its implementation and usage in clinical setting a practical challenge.