2379P - AVENANCE: Subgroup analysis of patients (pts) with advanced urothelial carcinoma (aUC) with histological variants from a real-world (RW) study of avelumab first-line maintenance (1LM)

Background

≈10% of bladder cancers have nonpure UC histology; these tumors are often underdiagnosed and represent an unmet treatment need. AVENANCE (NCT04822350) is evaluating avelumab 1LM in pts with aUC in France and has previously shown clinical activity in a heterogenous population (N=593). We present a subgroup analysis of pts with histological variants.

Methods

Eligible pts had aUC that had not progressed on 1L platinum-based chemotherapy (PBC) and previous, ongoing, or planned avelumab 1LM. The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), duration of treatment (DOT), and safety. Here, pts with nonpure UC (mixed UC with variants [UC-V] and pure variants [PV]) were analyzed.

Results

44/593 pts had aUC with histological variants; at data cutoff (March 30, 2023), median follow-up was 18.0 mo (range, 12.9-20.4 mo). Tumor histology was UC-V, including micropapillary and epidermoid, in 32 pts (72.7%) and PV in 12 (27.3%). At the start of 1L PBC, most pts had metastatic disease (UC-V, 96.9%; PV, 91.7%) and ECOG PS 0/1 (UC-V, 71.4%; PV, 55.6%). The most common 1L PBC was gemcitabine + carboplatin in 65.6% of pts with UC-V and 75.0% with PV. In pts with UC-V and PV, best response to 1L PBC was complete response in 18.8% and 33.3%, partial response in 59.4% and 58.3%, and stable disease in 21.9% and 8.3%, respectively. In all 44 pts, median DOT was 5.1 mo (95% CI, 2.8-17.4 mo); 34.1% were still receiving treatment at data cutoff. The table shows OS, PFS, and safety data in pts with aUC with histological variants and the overall population.

Conclusions

RW data from AVENANCE provide evidence of the effectiveness and safety of avelumab 1LM in pts with aUC, including histological variants. To our knowledge, this is the first analysis of avelumab 1LM in this pt population. Data are consistent with findings in the overall population.

Table: 2379P

NE, not estimable; NR, not reached; TRAE, treatment-related adverse event.

Clinical trial identification

NCT04822350; First posted, March 30, 2021.

Editorial acknowledgement

Medical writing support was provided by Manoshi Nath on behalf of Clinical Thinking and was funded by Pfizer and Merck.

Legal entity responsible for the study

The authors.

Funding

This study was sponsored by Pfizer, as part of an alliance between Pfizer and Merck (CrossRef Funder ID: 10.13039/100009945).

Disclosure

P. Barthelemy: Financial Interests, Personal and Institutional, Advisory Board: Amgen, Bristol Myers Squibb, Ipsen, Janseen-Cilag, MSD, Pfizer, Merck ; Financial Interests, Personal, Other, Travel and accommodations expenses: Astellas Pharma, Bristol Myers Squibb, Ipsen, Janseen-Cilag, MSD, Pfizer; Financial Interests, Personal, Other, Honoraria: Astellas Pharma, Bristol Myers Squibb, Ipsen, Janseen-Cilag, MSD, Novartis, Pfizer, Seagen, Merck. Y. Loriot: Financial Interests, Personal and Institutional, Advisory Board: Astellas Pharm, Bristol Myers Squibb, Immunomedics, Janssen, Loxo/Lilly, MSD, Pfizer, Roche, Seagen, Taiho Pharmaceutical; Financial Interests, Personal, Other, Travel and accommodations expenses: Astellas Pharma, Janssen Oncology, MSD, Roche, Seagen; Financial Interests, Institutional, Research Funding: Astellas Pharma, Basilea, Bristol Myers Squibb, Exelixis, Gilead Sciences, Incyte, Janssen Oncology, MSD, Nektar, Pfizer, Roche, Sanofi, Seagen, Taiho Pharmaceutical, Merck. A. Flechon: Financial Interests, Personal, Other, Travel and accommodations expenses: AAA HealthCare, Astellas Pharma, Bayer, Bristol Myers Squibb, Ipsen, Janssen-Cilag, MSD, Pfizer, Roche/ Genentech, Sanofi/Aventis; Financial Interests, Personal, Other, Honoraria: AAA HealthCare, Astellas Pharma, Bayer, Bristol Myers Squibb, Ipsen, Janssen-Cilag, MSD, Roche/Genentech, Sanofi/Aventis, Pfizer. M. Gross Goupil: Financial Interests, Personal, Advisory Role: Amgen, Astellas Pharma, AstraZeneca, Bristol Myers Squibb, Ipsen, Eisai, Janssen-Cilag, Merck, MSD, Pfizer; Financial Interests, Personal, Other, travel and accommodations expenses: Astellas Pharma, Bristol Myers Squibb, Ipsen, Janssen-Cilag, Merck, MSD, Pfizer; Financial Interests, Personal, Invited Speaker: Astellas Pharma, AstraZeneca, Bristol Myers Squibb, Eisai, Ipsen, Janssen. J. Eymard: Financial Interests, Personal and Institutional, Advisory Board: Astellas Pharma, Ipsen, Janssen; Financial Interests, Institutional, Research Funding: Bristol Myers Squibb, Ipsen, Pfizer. D. Pouessel: Financial Interests, Personal and Institutional, Advisory Role: Astellas Pharma, AstraZeneca, MSD, Pfizer; Financial Interests, Personal, Invited Speaker: Astellas Pharma, AstraZeneca, Bristol Myers Squibb, Ipsen, Janssen, MSD, Pfizer, Merck; Financial Interests, Personal, Other, Travel and accommodations expenses: MSD; Financial Interests, Personal, Other, travel and accommodations expenses: Pfizer; Financial Interests, Institutional, Funding: MSD. L. Francois: Financial Interests, Personal, Advisory Board, Honoraria: Janssen, Ipsen, MSD, Merck, Pfizer. C. Sajous: Financial Interests, Personal, Advisory Role: Bristol Myers Squibb, Merck, Pfizer, Lilly, Daiichi Sankyo, Merck, Pfizer. C. Josse: Financial Interests, Personal, Full or part-time Employment: Exystat; Financial Interests, Institutional, Research Funding: Pfizer. M. Solbes: Financial Interests, Personal and Institutional, Full or part-time Employment: Merck Santé S.A.S., Lyon, France, an affiliate of Merck KGaA. P. Lambert: Financial Interests, Personal and Institutional, Full or part-time Employment: Pfizer. C. Thibault: Financial Interests, Personal and Institutional, Advisory Role: AAA Healthcare, AstraZeneca, Bristol Myers Squibb, Ipsen, MSD, Pfizer, Merck; Financial Interests, Personal, Invited Speaker: Astellas Pharma, AstraZeneca, Bristol Myers Squibb, Ipsen, Janssen, MSD, Sanofi; Financial Interests, Institutional, Research Funding: AstraZeneca, Sanofi. All other authors have declared no conflicts of interest.