902P - Comparison of progression free and overall survival (OS) with bicalutamide and 4-weekly or 12-weekly triptorelin in androgen receptor positive (AR+) salivary gland cancer (SGC)

Background

There is phase II data supporting AR directed therapy with bicalutamide and leuprorelin in AR+ SGC. The EORTC1206 study has completed recruitment between 2012-21 randomising 149 patients with recurrent/metastatic (R/M) SGC patients to receive chemotherapy versus bicalutamide and triptorelin, and the results are awaited. Given the rarity of this disease, to capture outcome data for patients treated outside of trials, we report results for 20 patients with AR+ R/M-SGC treated with bicalutamide/ triptorelin on a UK named-patient scheme.

Methods

From 2018-24, 20 patients with AR+ R/M-SGC were treated with bicalutamide (50mg/day) and triptorelin (I.M. 3.75mg/4 weeks or 11.25mg/12 weeks) from day 7. Electronic records were reviewed to calculate physician-assessed radiological response rate, duration on treatment (DoT), progression-free survival (PFS) and overall survival (OS) from R/M disease. Kaplan-Meier survival analysis was performed in R (v4.4.0 for Mac).

Results

20 patients (17 male) with AR+ R/M-SGC were included. Median age was 66.5 years (range 55-82). Histology was salivary duct carcinoma (70%), carcinoma ex pleomorphic adenoma (20%), adenocarcinoma NOS (5%) and oncocytic carcinoma (5%). Primary site was parotid in 80% and submandibular in 15%. All patients received bicalutamide 50mg daily and triptorelin 4-weekly (30%), 12-weekly (40%), or 4-weekly (> 3 months) switching to 12-weekly (30%). Complete response was seen in 10.5%, partial response in 31.5%, and stable disease in 10.5%. Median DoT was 6.4 months (range 0.5–62.5), median PFS was 4.1 months (range 0.7-62.5) and median OS from treatment initiation was 13.5 months (range 1.5 to 62.5). No difference was seen in OS between the 4-weekly and 12-weekly groups (8.6 versus 13.0 months respectively; P=0.13. 8 recieved subsequent chemotherapy.

Conclusions

This study describes durable radiological responses in 42% of patients with AR+ R/M-SGC treated with bicalutamide and triptorelin. This represents a clinically meaningful option for these patients, and the results of the EORTC1206 are eagerly awaited.

Clinical trial identification

Editorial acknowledgement

Funding

University of Manchester, The Christie Charity.

Disclosure

K.J. Harrington: Financial Interests, Institutional, Advisory Board: Amgen, AstraZeneca, BMS, Boehringer Ingelheim, Merck, MSD, Pfizer, Replimune, Oncolys, Vyriad, Idera; Financial Interests, Institutional, Other, Honoraria for lectures: Amgen, AstraZeneca, BMS, Boehringer Ingelheim; Financial Interests, Institutional, Advisory Board, Advisory board for CD47 assets: Arch Oncology; Financial Interests, Institutional, Advisory Board, Development of DDR assets: ARTIOS; Financial Interests, Institutional, Advisory Board, Development of exosomal STING agonist: Codiak; Financial Interests, Institutional, Advisory Board, Development of oncolytic adenovirus: PsiVac; Financial Interests, Institutional, Funding, Research: AstraZeneca, Boehringer Ingelheim, MSD; Financial Interests, Institutional, Funding, Development of oncolytic HSV platform: Replimune; Non-Financial Interests, Leadership Role, Chair of Steering Committee: ART NET; Non-Financial Interests, Other, Member of Global Steering Committee: MR - Linac. R. Metcalf: Financial Interests, Personal, Advisory Board: Ayala, Bayer, Aptus Clinical, PCI Biotech, Oxsonics, Roche, Achilles Therapeutics; Financial Interests, Personal, Other, Honoraria: BMS, MSD, Sanofi. G. Betts: Financial Interests, Personal, Speaker’s Bureau, For family member: Seagen; Other, Personal, Other, Uncompensated relationship: MSD. All other authors have declared no conflicts of interest.