CLINICAL RESPONSE AND TIME TO PROSTATE-SPECIFIC ANTIGEN (PSA) PROGRESSION IN PATIENTS WITH METASTATIC CASTRATION-RESISTANT PROSTATE CANCER (MCRPC) RECEIVING SECOND-LINE CHEMOTHERAPY VERSUS ALTERNATIVE ANDROGEN RECEPTOR-TARGETED AGENTS (ARTA ...
Author(s)
Oh WK1, Cheng WY2, Miao R3, Vekeman F4, Gauthier-Loiselle M4, Duh MS2, Drea E3, Szatrowski T3
1The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA, 2Analysis Group, Inc., Boston, MA, USA, 3Sanofi US, Bridgewater, NJ, USA, 4Groupe d'analyse, Ltée, Montréal, QC, Canada
OBJECTIVES: The relationship between treatment sequence and outcomes in mCRPC is unclear. This retrospective cohort study assessed if second-line taxane-based chemotherapy vs alternative ARTA is associated with improved clinical response and time to PSA progression in patients with a lack of response to first-line ARTA in the US community oncology setting. METHODS: Using Altos electronic medical records, 345 mCRPC patients were identified who lacked response to first-line ARTA (abiraterone: N=289; enzalutamide: N=56) and received second-line chemotherapy (docetaxel: N=128; cabazitaxel: N=19), or alternative ARTA (enzalutamide: N=170; abiraterone: N=28) from 05/2011 to 10/2014. Outcomes were evaluated from second-line therapy initiation and compared between the two cohorts using one-sided tests. Clinical response (clinical note, ECOG performance status (PS) reduction by ≥1, ≥5% weight increase, or ≥2g/dl hemoglobin (Hb) increase over ≥3 months) and time to PSA progression (≥25% increase over nadir concentration) were assessed using logistic and Cox regressions adjusted for year, age, metastases, opioid use, ECOG PS, PSA, Hb, alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and albumin (Alb) levels. RESULTS: At start of second-line therapy, patients receiving chemotherapy vs ARTA were younger (median age, 74 vs 79 years) and had a poorer prognosis: higher mean PSA (439 vs 231 ng/mL), LDH (344 vs 234 μg/L) and ALP (241 vs 166 μ/L) levels, lower mean Hb levels (11 vs 12 g/dL), higher mean Halabi risk score (159 vs 137; JCO 2014:32;671–7), and more patients had Alb levels <lower limit of normal (25% vs 15%); all p <0.01. Patients in the chemotherapy vs ARTA cohort were more likely to have a clinical response (adjusted odds ratio=1.78, p=0.020) and longer time to PSA progression (adjusted hazard ratio=0.66, p=0.010). CONCLUSIONS: Second-line taxane-based chemotherapy vs second-line ARTA may be more suitable for patients with a lack of response to first-line ARTA and therefore should be further investigated in a prospective randomized trial.
Conference/Value in Health Info
2017-05, ISPOR 2017, Boston, MA, USA
Value in Health, Vol. 20, No. 5 (May 2017)
Code
PCN17
Topic
Clinical Outcomes
Topic Subcategory
Comparative Effectiveness or Efficacy
Disease
Oncology