Abstract 3666
Background
Immune-related adverse events (IRAEs) represent a clinical challenge, potentially limiting the clinical benefits of immunotherapy. Data suggests nivolumab and pembrolizumab IRAEs rates are similar but no comparisons across tumor types exist. Therefore, we studied IRAEs in patients (pts) with metastatic melanoma and non-small cell lung cancer (NSCLC) treated with anti-PD1 therapy.
Methods
All pts with metastatic melanoma and NSCLC seen at the Mayo Clinic Rochester and Florida from 2015 to 2018 were reviewed. Patients that received prior immunotherapies or thoracic radiation were excluded. Chi-square test was used to estimate differences in categorical data.
Results
Out of 510 pts, 266 (52%) had melanoma and 244 (48%) NSCLC. Baseline characteristics were similar across groups, except for sex (NSCLC: 51% women; melanoma: 40% women). 80% of the pts with NSCLC received chemotherapy prior to immunotherapy compared to 14% of the pts with melanoma. 75% (200) of melanoma pts received pembrolizumab and 66% (161) of NSCLC pts received nivolumab. Higher rates of IRAEs were observed in the melanoma pts (55% vs. 41%, <0.001) (Table). No difference in grade ≥3 IRAEs was observed. Melanoma pts were more likely to develop diarrhea/colitis and endocrinopathies compared to the NSCLC pts (19% vs. 7%, p < 0.008; 33% vs. 18%, p < 0.01, respectively). Contrarily, pts with NSCLC had higher rates of pneumonitis (14% vs. 6%, p < 0.007). Most pts resumed the anti-PD1 agent after developing IRAEs (60% and 57%, respectively). In 31% of the pts experiencing IRAEs the anti-PD1 agent was permanently discontinue due to toxicity.Table: 1218P
| Melanoma % (n) | NSCLC % (n) | p value | |
|---|---|---|---|
| IRAEs | 55 (146) | 41 (99) | <0.001 |
| Grade ≥2 IRAEs | 76 (110) | 75 (76) | 0.98 |
| Grade ≥3 IRAEs | 34 (49) | 36 (36) | 0.68 |
| Prescribed systemic steroids | 66 (97) | 60 (59) | 0.26 |
| Required intravenous steroids | 25 (37) | 27 (27) | 0.75 |
| IRAEs: Subtype (all grades) | |||
| Diarrhea/Colitis | 19 (28) | 7 (7) | 0.008 |
| Dermatologic Toxicities | 19 (28) | 22 (22) | 0.62 |
| Endocrinopathies | 33 (48) | 18 (18) | 0.01 |
| Pneumonitis | 6 (8) | 14 (14) | 0.007 |
| Transaminitis | 14 (21) | 9 (9) | 0.24 |
| Immunotherapy was restarted | 60 (88) | 57 (56) | 0.60 |
| Immunotherapy DC due to toxicity | 31 (45) | 31 (31) | 0.99 |
Conclusions
Patients with metastatic melanoma were more likely to develop IRAEs with anti-PD1 therapy. We observed differences in the IRAEs developed across groups. These associations could be attributed to intrinsic tumor characteristics or differences between anti-PD1 agents. Larger studies are needed to enhance our understanding of these differences.
Clinical trial identification
Legal entity responsible for the study
N. Duma.
Funding
Has not received any funding.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.