• Phase 2 study of anastrozole in rare cohorts of patients with estrogen receptor/progesterone receptor positive leiomyosarcomas and carcinosarcomas of the uterine corpus: The PARAGON trial (ANZGOG 0903).

      Edmondson, R J; email: richard.edmondson@manchester.ac.uk; O'Connell, R L; Banerjee, S; Mileshkin, L; Sykes, P; Beale, P; Fisher, A; Bonaventura, A; Millan, D; Nottley, S; et al. (2021-10-05)
      Aromatase inhibitors have been used empirically to treat a subset of patients with hormone receptor positive uterine leiomyosarcomas(LMS) and carcinosarcomas (UCS) mainly supported by retrospective data. We evaluated the activity of anastrozole in two rare cohorts; patients with recurrent/metastatic LMS and UCS enrolled in PARAGON, a basket trial of anastrozole in estrogen receptor (ER+)/progesterone receptor positive (PR+) gynecological cancers. An investigator-initiated, single-arm, prospective open-label trial of anastrozole 1 mg/day in patients with ER &/or PR + ve LMS or UCS with measurable disease, treated until progression or unacceptable toxicity. Primary endpoint was clinical benefit (complete/partial response + stable disease) rate (CBR) at 3 months. Secondary endpoints include progression-free survival (PFS), quality of life and toxicity. 39 eligible patients were enrolled, 32 with LMS and 7 with UCS. For the LMS cohort CBR at 3 months was 35% (95% CI: 21-53%) with a median duration of clinical benefit of 5.8 months. Best response was a partial response in one patient. Two patients remained on treatment for more than one year. The median progression-free survival was 2.8 months (95% CI: 2.6-4.9). For the UCS cohort CBR at 3 months was 43% (95% CI: 16-75%) with a median duration of clinical benefit of 5.6 months. Stable disease was seen in 3 patients but no objective responses were seen. The median progression-free survival was 2.7 months (95% CI, 1.1-8.2). Safety was acceptable with 5/39 evaluable patients showing grade 3 toxicities. Whilst objective response rates with anastrozole are low, the clinical benefit rate and good tolerance suggests that aromatase inhibitor therapy may have a role in a subset of patients with metastatic LMS and UCS. [Abstract copyright: Copyright © 2021. Published by Elsevier Inc.]