(UroToday.com) Dr. Grivas presented the initial work of PATRIOT-II, which is a retrospective, observational, US-based, multicenter, real-world (RW) study of avelumab first-line maintenance (1LM) in locally advanced/metastatic urothelial carcinoma (la/mUC). Specifically today, he is presenting the baseline characteristics of the cohort.
The JAVELIN Bladder 100 clinical trial1 demonstrated a significant overall survival and progression-free survival benefit with avelumab 1LM + best supportive care (BSC) vs BSC alone for la/mUC not progressing on platinum-based chemotherapy (PBC). PATRIOT-II aims to describe real world (RW) data for avelumab 1LM treatment (tx) of patients (pts) with la/mUC. The study in progress aims to examine real-world patient characteristics, treatment patterns and clinical outcomes in an observation cohort.
The study design is below:
PATRIOT-II collected data from pts with la/mUC treated in 37 geographically dispersed oncology practices/communities and academic centers in the US. Pts who initiated avelumab 1LM following PBC were retrospectively enrolled and will be followed up via medical record review for 52 weeks post avelumab 1LM initiation. This analysis focused on patient characteristics and treatment data from la/mUC diagnosis through the PBC period and at avelumab 1LM initiation. Disease and PBC treatment characteristics, as well as response to PBC, were assessed. All analyses were descriptive.
A total of 160 patients were enrolled (Table below), 118 (74%) were white, non-Hispanic, 16 (10%), were Black, Asian, or Hispanic, and the rest unknown; 102 (64%) were current or former smokers.
Looking at disease status and characteristics at PBC initiation:
77 (48%) were tested for PD-L1 via various assays, with 44 (57%) of those tumor samples reported as positive.
Next, below is summarized the PBC administration and response:
1L PBC was cisplatin-based in 100 (63%) of pts and carboplatin-based in 60 (38%). Pts received a median of 4 PBC cycles (interquartile range [IQR], 3-6) for a median of 13 weeks (IQR, 10-17). 31 (19%) discontinued PBC due to unacceptable side effects/toxicity. The best observed response was complete response in 21 (13%), partial response in 109 (68%), and stable disease in 17 (11%), with the remainder unknown. The median time to first imaging was 10 weeks (IQR, 5-14) after PBC initiation. 23 (14%) were hospitalized while receiving PBC, and 25 (16%) were seen in the emergency department.
Pts proceeded to avelumab 1LM at a median of 4 weeks (IQR, 3-6) following PBC completion. Avelumab was administered at 800 mg every 2 weeks in 130 (81%), 10 mg/kg in 15 (9%), <800 mg in 8 (5%), and >800 mg in 7 (4%) pts.
Based on all of this, Dr. Grivas concluded that in this US real-world population (N=160),
- 62.5% of patients received cisplatin based chemo, while 37.5% received carboplatin based chemo
- 13% had CR, 68% had PR, 11% had stable disease, and 8% had unknown best response
- Patients started on avelumab at a median of 4 weeks after completion of PBC, most at a standard dose of 800 mg once every 2 weeks
Presented by: Petros Grivas, MD, PhD | University of Washington; Fred Hutchinson Cancer Center
Written by: Thenappan (Thenu) Chandrasekar, MD – Urologic Oncologist, Associate Professor of Urology, University of California, Davis @tchandra_uromd on Twitter during the 2023 Genitourinary (GU) American Society of Clinical Oncology (ASCO) Annual Meeting, San Francisco, Thurs, Feb 16 – Sat, Feb 18, 2023.
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