461P - Spectrum of immune related adverse events (irAE) on treatment with checkpoint inhibitors and its association with survival: A real-world experience from India

Background

Immune checkpoint inhibitors (ICIs) are associated with a unique spectrum of side effects known as immune related adverse events (irAE). It has also been hypothesized that occurrence of irAE is associated with better survival. There is paucity of literature of the safety profile of ICIs in India and its association with survival.

Methods

An ambi-directional observational study was conducted of patients who received treatment with ICI (PD-1/PDL-1 inhibitors) at our centre between April 2016 -October 2021. They were followed up till May 31^st 2022. Organ specific irAE toxicities were graded according to CTCAE v 5.0. Kaplan Meir was used for analysis of survival events.

Results

215 patients received anti-PD-1/PDL-1 monoclonal antibodies at our centre between April 2016- October 2021. mRCC (n=65,30.2 %), mNSCLC (n=62, 28.8%) mHNSCC (n=30, 14%) were the most common indications. The most common ICIs used were Nivolumab (n=162, 75.3%), Pembrolizumab (n =41,19%) Any grade organ related irAE occurred in 94 patients (43.7%), Grade 3 irAEs in 16 patients (7.4%). The most common irAes were Thyroid dysfunction (n=51, 23.7%), Dermatological irAES (n=40,18.6%), Diarrhea (n=12, 5.5%). Rare irAes of encephalitis (n=2), immune mediated retinopathy (n=1), myocarditis(n=1), cholangitis (n=1) were noted.Oral/IV Steroids were required in 20 patients (9.3%). Treatment discontinuation due to irAEs occurred in 14 patients (6.5%), Death due to irAEs in 5 patients (2.3%). A higher objective response rate (ORR) of 69.2% was noted in those with irAE v/s 33.1% in those without irAE (p<0.01). Those with any grade irAE had significantly better survival (median OS: 21 months) as compared to those who did not ( median OS: 7 months, p<0.01). Among those with irAE,there was no significant difference (p=0.395) in survival between those who received systemic steroids for it's treatment (median OS: 15 months) as compared to those who did not (median OS:22 months).

Conclusions

Treatment with PD-1/PDL-1 monoclonal antibodies was well tolerated with Grade 3 irAEs noted in 7.4%. Thyroid dysfunction and Dermatological toxicities were the most common. Occurrence of irAE correlated with better ORR as well as prolonged survival.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Dr. Nitin Yashas.

Funding

Has not received any funding.

Disclosure

A. Rauthan: Financial Interests, Personal, Advisory Role: BMS, Merck, Eli Lilly, Pfizer, Roche, MSD. All other authors have declared no conflicts of interest.