PII-037 - REAL-WORLD CHARACTERIZATION OF DRUG-DRUG INTERACTIONS AMONG PATIENTS WITH ONCOGENE-DRIVEN NON-SMALL CELL LUNG CANCER USING TYROSINE KINASE INHIBITORS

K. Paydary¹, N. Otto¹, A. Poles¹, J. Borgia², M. Fidler¹; ¹Rush University Medical Center, Department of Medicine, Section of Hematology, Oncology and Cell Therapy, Chicago, IL, USA, ²Rush University Medical Center, Departments of Anatomy & Cell Biology and Pathology, Chicago, IL, USA.

Background: With improved outcomes of patients (pts) with non-small cell lung cancer (NSCLC) who take tyrosine kinase inhibitors (TKIs), there is an increased risk of drug-drug interactions (DDI). We aimed to characterize DDIs in pts with NSCLC taking TKIs using Real-world data (RWD).

Methods: We retrospectively collected data of pts with NSCLC on TKIs in our institution from 2012 to 2022 including concomitant medications, overall survival (OS) and toxicity (tox) reports. Lexicomp® drug interaction tool was used to identify DDIs at time of treatment start, defined as categories C (monitor therapy), D (consider treatment modification) and X (avoid combination). Correlative analysis was performed to elucidate associations between DDI and pt outcomes.

Results: The number of analyzed treatment courses was 160 from 153 pts taking 15 TKIs, seven pts treated with two TKIs over time; patient features: 95 (59.4%) female, median age of 65 with 123 (76.9%) and 37 (23.1%) pts started TKI in the metastatic and adjuvant settings, respectively. Thirty seven pts (23.1%) required TKI dose reduction due to tox and 29 pts (18.1%) had TKI held for tox. The estimated median OS, duration of treatment with TKI, and duration of time between TKI start and earliest tox report were 31 (IQR 15.7-56.5), 13 (IQR 4-24) and 1 (IQR 0.5-2) months, respectively. In total, any DDIs were identified in 65 pts (40.6%), with category X/D DDI in 22 (13.8%) pts. The most common DDI included use of antiacids (n=15), moderate-to-strong CYP3A4 inducers (n=15), QT prolonging meds (n=10) and Pgp/ABCB1 inhibitors (n=9). Pts with any DDI at time of TKI start were more likely to have TKI treatment interrupted due to tox (χ^2=10.42, p=0.005). This correlation was similar among pts who had DDI category X/D (χ^2=10.99; P=0.004). While not significant, pts with DDI had shorter duration between TKI start and earliest tox report (mean 1.3 vs. 2.4 months respectively). Pts with DDI were taking more scheduled (7.2±3.8 vs 5.2±3.4, p=001) and as needed (2.7±1.7 vs 1.8±1.4, p=0.001) meds at time of TKI start.

Conclusion: DDIs among pts taking TKIs in this RWD set were associated with a high percentage of dose reductions and interruptions. Future prospective studies to further elucidate the association between DDIs and patient reported outcomes are warranted.