244MO Primary results from IMscin002: A study to evaluate patient (pt)- and healthcare professional (HCP)-reported preferences for atezolizumab (atezo) subcutaneous (SC) vs intravenous (IV) for the treatment of NSCLC

Atezo SC is approved for use in all atezo IV indications in the EU and UK. Results from IMscin001 (NCT03735121) showed that the pharmacokinetics, efficacy and safety of atezo SC and IV were consistent. IMscin002 (NCT05171777) is a phase II, randomized, multicentre, cross over trial investigating pt- and HCP-reported preference for atezo SC vs IV for the treatment of pts with NSCLC. Pts with PD-L1+ resected NSCLC (Stage II, IIIA, or selected IIIB; AJCC 8th ed) who had prior chemotherapy and no evidence of recurrence, and untreated pts with PD-L1 high Stage IV NSCLC were screened. Eligible pts ≥18 years old and EGFR/ALK wild-type were randomized 1:1 to receive atezo SC (1875 mg) or IV (1200 mg) Q3W. After Cycle 3, pts switched over to the alternative route of administration; after Cycle 6, pts stated their preference and selected treatment for the continuation period. Pts with resected NSCLC continued treatment for ≤16 cycles. Pts with advanced NSCLC continued treatment until investigator-determined loss of clinical benefit. The primary endpoint was pt preference for atezo SC vs IV at Cycle 6. Key secondary endpoints: safety and pt-reported outcomes assessed by questionnaire. At data cutoff (9 Nov 2023), 179 pts were randomized; 117 pts had Stage IV NSCLC and 62 pts had resected NSCLC. The completion rate for the pt preference questionnaire was 97.6% (n=123/126): most pts (70.7%) preferred atezo SC (n=87, 95% CI 61.9–78.6); 21.1% preferred IV (n=26); 8.1% had no preference (n=10). Pts' main reasons for preferring atezo SC were that it reduces time in the clinic (64.4%, n=56/87) and is a more comfortable route of administration (46.0%, n=40/87). After Cycle 6, most pts (79.4%) chose atezo SC for the continuation period. Overall, 85.8% of pts were very satisfied/satisfied with atezo SC vs 75.2% of pts with IV. No new safety findings were identified, and no safety concerns related to switching between treatments were reported. IMscin002 met its primary endpoint: pts preferred atezo SC vs IV. The overall safety profile was consistent with prior reports. These results support previous findings that pts prefer SC to IV formulations.