Real-world comparison of cabazitaxel vs. 177-lutetium-PSMA radioligand therapy in metastatic castration resistant prostate cancer.

Abstract

70 Background: 177-Lutetium Prostate-specific membrane antigen (Lu-PSMA) therapy is under current scientific investigation and aims to become an established part in treatment of metastatic castration resistant prostate cancer (mCRPC). However, real-world evidence in treatment comparison is scant. Methods: We relied on the FRAMCAP database and compared cabazitaxel vs. Lu-PSMA therapy in mCRPC patients regarding progression-free (PFS) and overall (OS). Sensitivity analyses addressed 2 nd to 4 th line mCRPC patients to approximate current Phase-III patient selection criteria. Results: Of 373 mCRPC patients, 14% received cabazitaxel vs. 65% Lu-PSMA vs. 21% both. Patients undergoing Lu-PSMA therapy were significantly older (median 72 vs. 66 years, p<0.01) and displayed a higher proportion of ECOG ≥2 (12 vs. 5.0%, p=0.1), relative to cabazitaxel patients. Rates of PSA50 were 32% vs. 0% for Lu-PSMA vs. cabazitaxel. In outcome analyses, significant superior median PFS was observed for Lu-PSMA vs. cabazitaxel (13.4 vs. 7.1 months, p<0.001), even after multivariable adjustment (HR: 0.38, p<0.001). Regarding OS, rates also significantly differed with median OS of 14.7 vs. 16.5 vs. 29.6 months for cabazitaxel vs. Lu-PSMA vs. both treatments (p<0.01). In sensitivity analyses of 2 nd to 4 th line mCRPC, PFS rates and median OS rates for cabazitaxel vs. Lu-PSMA vs. both therapies qualitatively remained the same compared to the entire cohort. Conclusions: In real-world setting, Lu-PSMA provides significantly better PFS and qualitatively better OS rates compared to cabazitaxel chemotherapy and should therefore be considered as a valuable treatment option for advanced mCRPC patients according to the EMA-approval. Characteristics of 296 metastatic castration resistant prostate cancer (mCRPC) patients stratified according to treatment of cabazitaxel vs. 177 - Lutetium- prostate-specific membrane antigen radioligand therapy (Lu-PSMA). Characteristic N Overall,N = 296 1 CabazitaxelN = 52 (18%) 1 Lu-PSMA,N = 244 (82%) 1 p-value 2 Age at mCRPC, years 192 71 (64, 76) 66 (58, 71) 72 (66, 78) <0.001 PSA at m CRPC, ng/ml 141 18 (6, 72) 63 (12, 144) 15 (6, 64) 0.044 Number of CRPC lines 296 3 (2, 4) 4 (3, 5) 3 (2, 4) <0.001 Cycles systemic treatment 229 3 (2, 6) 5 (3, 6) 3 (2, 6) 0.031 PSA response, % 39 20 (0, 66) 15 (0, 23) 25 (0, 68) 0.3 PSA50 39 11 (28%) 0 (0%) 11 (32%) 0.3 PSA90 39 5 (13%) 0 (0%) 5 (15%) 0.9 ECOG status at mCRPC 109 0.10 0 52 (48%) 14 (70%) 38 (43%) 1 45 (41%) 5 (25%) 40 (45%) >=2 12 (11%) 1 (5%) 11 (12%) Cardiovascular disease 183 66 (36%) 13 (35%) 53 (36%) 0.9 Gleason Score 8-10 259 181 (70%) 39 (80%) 142 (68%) 0.10 De Novo mHSPC 290 161 (56%) 33 (63%) 128 (54%) 0.2 High volume mHSPC 146 99 (68%) 24 (73%) 75 (66%) 0.5 Metastatic sites at mCRPC 130 0.8 M1a 14 (11%) 3 (13%) 11 (10%) M1b 104 (80%) 20 (83%) 84 (79%) M1c 12 (9%) 1 (4%) 11 (10%) Treatment mHSPC 126 0.034 ADT mono 25 (20%) 4 (20%) 21 (20%) ARSI 58 (46%) 4 (20%) 54 (51%) Docetaxel 34 (27%) 10 (50%) 24 (23%) Triplet 3 (2%) 1 (5%) 2 (2%) Other 6 (5%) 1 (5%) 5 (5%) Treatment 1st line mCRPC 296 <0.001 ADT mono 29 (10%) 6 (12%) 23 (9%) Chemotherapy 53 (18%) 19 (37%) 34 (14%) Lu-PSMA 28 (10%) 0 (0%) 28 (11%) ARSI 163 (55%) 26 (50%) 137 (56%) PARPi +/- ARSI 1 (0.3%) 0 (0%) 1 (0.4%) Radium 20 (7%) 0 (0%) 20 (8%) None/Other/NA 2 (1%) 1 (2%) 1 (0.4%) Treatment 2nd line mCRPC 296 <0.001 Chemotherapy 69 (23%) 27 (52%) 42 (17%) Lu-PSMA 73 (25%) 0 (0%) 73 (30%) ARSI 114 (39%) 25 (48%) 89 (36%) PARPi+/- ARSI 5 (2%) 0 (0%) 5 (2%) Radium 13 (4%) 0 (0%) 13 (5%) None/Other/NA 22 (7%) 0 (0%) 22 (9%) 1 Median (IQR); n (%). 2 Wilcoxon rank sum test; Fisher’s exact test; Pearson’s Chi-square test. PSA: Prostate-specific antigen, ECOG: Eastern Cooperative Oncology group, mHSPC: metastatic hormone-sensitive prostate cancer, ADT: Androgen deprivation therapy, ARSI: Androgen receptor signaling inhibitor, PARPi: poly-(ADP-ribose)-polymerase inhibitors, NA: Unknown.