Comparing rate of immunotherapy treatment change due to toxicity by gender.

Abstract

2656 Background: Immunotherapy (IO) is associated with a variety of treatment related toxicities. However, the impact of toxicity on the treatment discontinuation rate between males and females is unknown. We hypothesized that immune related adverse events would lead to more frequent treatment changes in females since autoimmune diseases occur more frequently in females Methods: The Oncology Research Information Exchange Network (ORIEN) Avatar Database collects clinical data from ten different United States cancer centers, where patients receive IO. Of 1,035 patients receiving IO, 447 patients were analyzed, excluding those (N = 573) who did not have documentation noting if a patient changed treatment. 15 additional patients with an unknown or gender-specific cancer were excluded. All cancer types and stages were included. Primary endpoint was documented treatment change due to toxicity. Significance was calculated with logistic regression, linear regression, chi-squared test for categorical variables and Mann-Whitney U test for continuous nonparametric variables. Results: 447 patients (281 males and 166 females) received IO treatment for cancer. The most common cancers treated were kidney, skin, and lung for 99, 84, and 54 patients, respectively. Females had a shorter IO course compared to males on Mann-Whitney U test (median 3.7 vs 5.1 months, respectively, p=0.02) and multivariable linear regression (Beta -3.87, 95% CI -6.591, -1.149, p=0.005). 54 patients changed IO treatment due to toxicity. There was no significant difference in the rate of treatment change due to toxicity between females and males on chi-square test (11.4% vs. 12.5%, respectively, p = 0.75) and logistic regression (Table). Pembrolizumab, Nivolumab, Ipilimumab/Nivolumab, Ipilimumab, Durvalumab, Avelumab, and Atezolizumab were given to 16, 14, 9, 9, 3, 2 and 1 patients who changed treatment due to toxicity, respectively. The median length of time for IO treatment prior to change for toxicity was 3 months (IQR 1.4 – 5.9 months). Significantly more patients with COPD changed treatment due to toxicity (Table). Conclusions: Females received a shorter course of IO than males. However, there was no significant difference in the treatment discontinuation rate due to toxicity between males and females receiving IO. Toxicity related treatment change was associated with COPD. Studies with larger sample sizes with more granular data (i.e., type of adverse effects) are needed to truly characterize if a difference between genders and IO toxicity exists. [Table: see text]