Background: Previous studies have suggested that tumor growth rate (g), estimated using prostate-specific antigen values, is associated with overall survival (OS) in prostate cancer (Wilkerson, 2016). We performed a retrospective pooled analysis in non-small cell lung cancer (NSCLC) to investigate the extent to which g values estimated using radiological tumor measurements in clinical trials are associated with survival. Methods: We identified 24 randomized clinical trials submitted to FDA between 2013 and 2019 investigating either immune checkpoint inhibitor (ICI) or targeted therapy (TT) in pts with metastatic NSCLC. Of 9934 patients (pts) enrolled, 5532 pts (2401, 1189, and 1942 pts treated with ICI, TT, and chemotherapy respectively) had sufficient data to derive a valid g. The g was evaluated by both type and line of therapy. Pts were then grouped according to quartiles of g, with Q1 being the lowest. We calculated OS and progression-free survival (PFS) for each group via the Kaplan-Meier method, and used the Cox model for group comparison. Results: Median g was 9.7E-4, 1.4E-3, and 2.2E-3/day, and median OS was 34.2, 21.3, and 15.3 months (mo), in pts treated with TT, ICI, and chemotherapy, respectively, regardless of lines of therapy. When treated with the same type of therapy, pts receiving 2^nd line therapy had a higher median g than those receiving 1^st line. The median survival and log-rank hazard ratios for pts treated with 1^st line ICI monotherapy are shown in the Table. Conclusions: TT is associated with the lowest median g, followed by ICI, and then chemotherapy, perhaps due to patient selection, better inherent biology/natural history, or favorable results of TT on selected tumors. Regardless, we found that g is inversely associated with survival, across treatment types. This relationship is also observed in pts treated with the same type and line of therapy (for example, 1^st line ICI), where Q1 has the longest survival, followed by Q2, Q3, and then Q4. In summary, our exploratory analysis suggests that g derived from radiological tumor measurements in NSCLC may relate to survival. Prospective studies are needed to evaluate if g might be an earlier endpoint compared to classical response criteria.

*NR = Not Reached