ABSTRACT
OBJECTIVE: To assess the association between achievement of prostate-specific antigen (PSA) levels ≤0.2 ng/mL (henceforth 'ultralow') and clinical outcomes in patients in the 'Targeted Investigational Treatment Analysis of Novel Anti-androgen' (TITAN) study (ClinicalTrials.gov Identifier NCT02489318) with metastatic castration-sensitive prostate cancer (mCSPC). PATIENTS AND METHODS: Patients in the TITAN study with mCSPC were randomised to 240 mg/day apalutamide (n = 525) or placebo (n = 527) plus androgen-deprivation therapy. This post hoc analysis assessed the achievement of a PSA level of 0.2->0.02 ng/mL ('ultralow one' [UL1]) and ≤0.02 ng/mL ('ultralow two' [UL2]) vs >0.2 ng/mL with apalutamide treatment and its association with radiographic progression-free survival (rPFS), overall survival (OS), time to castration-resistant PC (TTCRPC), and time to PSA progression (TTPP). The landmark analysis and Kaplan-Meier methods were used. RESULTS: By 3 months, more patients achieved UL1 and UL2 with apalutamide (38% and 23%) vs placebo (15% and 5%). In the apalutamide-treated patients, UL2 vs PSA >0.2 ng/mL at landmark 3 months was associated with significantly longer rPFS (hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.14-0.54), OS (HR 0.24, 95% CI 0.13-0.43), TTCRPC (HR 0.2, 95% CI 0.11-0.38), and TTPP (HR 0.11, 95% CI 0.04-0.27; nominal P values all <0.001); this association was also observed but less pronounced for UL1. Similar findings were observed at 6 months. Early onset of decline to UL2 by 3 months was associated with improved survival vs PSA >0.2 ng/mL anytime (HR 0.12, 95% CI 0.06-0.22; P < 0.001) in apalutamide-treated patients. CONCLUSIONS: In this post hoc analysis of TITAN, patients with the deepest PSA decline derived the greatest benefit. These results extend our findings of apalutamide efficacy in the overall TITAN population, underscoring the clinical value of PSA kinetics as a marker for treatment efficacy. PATIENT SUMMARY: Patients with metastatic prostate cancer that is sensitive to ongoing hormonal treatment benefited significantly from the addition of apalutamide compared with placebo. Those who achieved rapid and deep PSA reduction had the greatest survival benefit.
ABSTRACT
INTRODUCTION: Patients with advanced, epidermal growth factor receptor (EGFR)-mutated, non-small cell lung cancer (NSCLC) with Exon 20 insertion mutations (Exon20ins) have poor prognoses, exacerbated by a previous lack of specific treatment guidelines and unmet need for targeted therapies. Amivantamab, an EGFR and MET bispecific antibody, demonstrated efficacy and tolerability in patients with advanced EGFR-mutated NSCLC with Exon20ins following platinum-based therapy in CHRYSALIS (NCT02609776; Cohort D+). Since CHRYSALIS was single-arm, individual patient data (IPD)-based adjusted analyses versus similar patients in real-world clinical practice (RWCP) were conducted to generate comparative evidence. METHODS: RWCP cohorts were derived from seven European and US real-world sources, comprising patients fulfilling CHRYSALIS Cohort D+ eligibility criteria. Amivantamab was compared with a basket of RWCP treatments. Differences in prognostic characteristics were adjusted for using inverse probability weighting (IPW; average treatment effect among the treated [ATT]). Balance between cohorts was assessed using standardized mean differences (SMDs). Overall response rate (ORR; investigator- [INV] and independent review committee-assessed [IRC]), overall survival (OS), progression-free survival (PFS; INV and IRC) and time-to-next treatment (TTNT) were compared. Binary and time-to-event endpoints were analyzed using weighted logistic regression and proportional hazards regression, respectively. RESULTS: Pre-adjustment, baseline characteristics were comparable between cohorts. IPW ATT-adjustment improved comparability, giving closely matched characteristics. ORR (INV) was 36.8% for amivantamab versus 17.0% for the adjusted EU + US cohort (response rate ratio [RR]: 2.16). Median OS, PFS (INV) and TTNT were 22.77 versus 12.52 months (hazard ratio [HR]: 0.47; p < 0.0001), 6.93 versus 4.17 months (HR: 0.55; p < 0.0001) and 12.42 versus 5.36 months (HR: 0.44; p < 0.0001) for amivantamab versus the adjusted EU + US cohort, respectively. Results were consistent versus EU- and US-only cohorts, and when using IRC assessment. CONCLUSION: Adjusted comparisons demonstrated significantly improved outcomes for amivantamab versus RWCP, highlighting the value of amivantamab in addressing unmet need in patients with advanced EGFR Exon20ins NSCLC following platinum-based therapy. TRIAL REGISTRATION: CHRYSALIS: NCT02609776.