Abstract A120: Sex differences in tolerability and response to immune checkpoint inhibitors in non-small cell lung cancer patients
Authors: Duma Narjust , Azzouqa Abdel-Ghani , Yadav Siddhartha , Hoversten Kahterine , Reed Clay , Sitek Andrea , Enninga Elizabeth , Paludo Jonas , Kottschade Lisa , Mansfield Aaron , Manochakian Rami , Dronca Roxana , Adjei Alex 
Published: August 2020

Background: Sex differences in non-small cell lung cancer (NSCLC) outcomes have been described. Immune-related adverse events (IRAEs) have emerged as a serious clinical problem in the use of immune checkpoint inhibitors (ICI). Risk factors for IRAEs and their association with response to therapy remain controversial. Sex differences in innate and adaptive immune responses have been observed but the association of these differences with IRAEs remains unclear. Therefore, we studied sex differences in IRAEs and their association with response to therapy.

Methods: All patients with metastatic NSCLC treated with anti-PD1 and anti-PDL1 therapy at Mayo Clinic Rochester and Florida from 2015 to 2018 were reviewed. Patients receiving treatment at an outside facility with history autoimmune disorders or radiation-induced pneumonitis were excluded. Chi-square test was used to estimate differences in categorical data. Kaplan-Meier method was used for time-to-event analysis.

Results: A total of 231 patients were identified; 120 (52%) were women and 111 (48%) were men. Baseline characteristics and ICI distribution were similar among groups. Women were more likely to experience IRAEs compared to men (48% vs. 31%, p&lt;0.008). Among patients with IRAEs, women were more likely to be prescribed systemic steroids (63% vs. 41%, p&lt;0.02). On the other hand, no significant differences were observed in the administration of intravenous steroids. Women were more likely to develop pneumonitis (23% vs. 12%, p&lt;0.03) and arthralgias (17% vs. 3%, p&lt;0.04). However, dermatologic toxicities (35% vs. 9%, p&lt;0.002) were more commonly seen in men. In 17% of women the ICI was discontinued due to toxicity (men 7%). Besides sex, no other clinical characteristic was associated with increased IRAEs. Women with IRAEs were more likely to have a radiographic response compared with women without IRAEs (78% vs. 23%, p&lt;0.0001), although this was not observed in men (37% vs. 26%, p&gt;0.22). Better PFS was observed in women with IRAEs (10 months vs. 3.3 months, p&lt;0.0006) compared to women without IRAEs.

Conclusions: Women with metastatic NSCLC are more likely to experience IRAEs compared to men. We also observed sex differences in the frequency of certain IRAEs. In addition, an association between IRAEs and response to therapy was observed in women. Larger studies are needed to investigate the mechanisms underlying these associations.

Citation Format: Narjust Duma, Abdel-Ghani Azzouqa, Siddhartha Yadav, Kahterine Hoversten, Clay Reed, Andrea Sitek, Elizabeth Enninga, Jonas Paludo, Lisa Kottschade, Aaron Mansfield, Rami Manochakian, Roxana Dronca, Alex Adjei. Sex differences in tolerability and response to immune checkpoint inhibitors in non-small cell lung cancer patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A120.