A phase 2 study of anastrozole in patients with oestrogen receptor and/progesterone receptor positive recurrent/metastatic granulosa cell tumours/sex-cord stromal tumours of the ovary: The PARAGON/ANZGOG 0903 trial.

Background: Hormonal therapies are commonly prescribed to patients with metastatic granulosa cell tumours (GCT), based on high response rates in small retrospective studies. Aromatase inhibitors (AIs) are reported to have high response rates and an accepted treatment option. We report the results of a phase 2 trial of an AI in recurrent/metastatic GCTs.
Methods: 41 patients with recurrent ER/PR + ve GCT received anastrozole 1 mg daily until progression or unacceptable toxicity. The primary endpoint was clinical benefit rate (CBR) at 12 weeks, evaluated by RECIST1.1 criteria. Secondary endpoints included progression-free survival (PFS), CBR duration, quality of life and toxicity.
Results: The CBR at 12 weeks in 38 evaluable patients was 78.9%, which included one (2.6%; 95% CI: 0.5-13.5%) partial response and 76.3% stable disease. Two additional patients without measurable disease were stable, based on inhibin. Median PFS was 8.6 m (95% CI 5.5-13.5 m). There were delayed responses observed after 12 weeks with a total of 4 pts. (10.5%; 95% CI 4.2%-24.1%) with a RECIST partial response; 23 (59%) patients were progression-free at 6 months. The adverse effects were predominantly low grade.
Conclusions: This is the first prospective trial of hormonal therapy in GCTs. Although there was a high CBR, the objective response rate to anastrozole was much lower than the pooled response rates of >70% to AIs reported in most retrospective series and case reports. PARAGON demonstrates the importance of prospective trials in rare cancers and the need to reconsider the role of AIs as single agents in GCTs.
Competing Interests: Declaration of Competing Interest SB: Institutional grants from Astrazeneca, Tesaro, GSK. Personal fees for advisory boards/lectures: Amgen, Astrazeneca, Clovis, Genmab, GSK, Immunogen, Mersana, MSD, Merck Sereno, Mersana, Oncxerna, Pfizer, Roche, Takeda, Tesaro, outside the submitted work. KS: Research funding to institution, Bayer and Amgen. Personal fees from Merck, Amgen, Servier, BMS, IPSEN, Competitive Drug Development, outside the submitted work. AC: Grants from Cancer Research UK and Astrazeneca, personal fees from AstraZeneca, GSK, Tesaro, Clovis Oncology, Eisai, outside the submitted work. RL: Personal fees from Tesaro and Roche outside the submitted work. MH: Research funding to institution Merck, BMS, Clovis Oncology. Honoraria for Advisory Boards/ Lectures: Amgen, AZ, Clovis Oncology, GSK, MSD, Roche outside the submitted work. CG: Research funding to institution: AstraZeneca, Novartis, Aprea, Nucana, Tesaro, BerGen Bio. Honorary for advisory boards/lectures: Roche, AstraZeneca, MSD, GSK, Tesaro, Nucana, Clovis, Foundation One, Sierra Oncology, Cor2Ed, Takeda. PS: Grant from University of Sydney. RE: Personal fees from Arquer Diagnostics, GSK, Clovis oncology outside submitted work. MF: personal fees from Astra Zeneca, MSD, GSK, Tesaro, Lilly, Takeda and Novartis; institutional grants from Astra Zeneca, Novartis and Beigene, other from Abbvie and ACT Genomics outside the submitted work. All other authors (MT, ROC, DM, SN, VMM, TB, JCG, PTG, OM, LA, CK, KC, LD, NB) report no disclosures of interest.
(Copyright © 2021. Published by Elsevier Inc.)