COSMIC-021 Phase Ib Study of Cabozantinib Plus Atezolizumab: Results from the Locally Advanced or Metastatic Urothelial Carcinoma Cohorts
Mené sur 121 patients atteints d'un carcinome urothélial inopérable de stade localement avancé ou métastatique, cet essai de phase 1b évalue l'efficacité, du point de vue du taux de réponse objective et de la survie sans progression, et les effets indésirables du cabozantinib (administré par voie orale) en combinaison avec l'atézolizumab (administré par voie intraveineuse)
Purpose : The COSMIC-021 study assessed the safety and efficacy of cabozantinib plus atezolizumab in advanced solid tumors. Presented here are results from the expansion cohorts with advanced urothelial carcinoma (UC).
Methods : This phase Ib study (ClinicalTrials.gov identifier: NCT03170960) enrolled patients with inoperable locally advanced/metastatic UC into four tumor cohorts: first-line cisplatin-eligible (cis-eligible), first-line cisplatin-ineligible (cis-ineligible), previous platinum-containing chemotherapy (previous chemotherapy-treated), and previous immune checkpoint inhibitor (ICI)–treated. Patients received oral cabozantinib 40 mg once daily and intravenous atezolizumab 1,200 mg once every 3 weeks. The primary end point was objective response rate (ORR), as assessed by the investigator per RECIST v1.1 every 6 weeks for 12 months and every 12 weeks thereafter; the secondary end point was safety.
Results : A total of 121 patients (previous ICI-treated cohort, n = 31, and each of the other cohorts, n = 30) received study treatment from March 2018 to November 2021. The ORR (95% CI) was 30% (15 to 49) for cis-eligible, 20% (8 to 39) for cis-ineligible, 27% (12 to 46) for previous chemotherapy-treated, and 10% (2 to 26) for previous ICI-treated cohorts. The median progression-free survival (95% CI) was 5.5 (1.6 to 11.6), 5.6 (3.1 to 11.1), 5.4 (1.6 to 7.6), and 3.0 (1.8 to 5.5) months, respectively. Grade 3 or 4 treatment-related adverse events (TRAEs) were experienced by 43%, 67%, 57%, and 45% of patients, respectively. TRAEs led to discontinuation of all treatment components in 17%, 13%, 3%, and 19%, respectively. No grade 5 TRAEs were reported in any cohort.
Conclusion : The novel combination of cabozantinib plus atezolizumab exhibited clinical activity in advanced UC that is cis-eligible, cis-ineligible, or previously treated with platinum-containing chemotherapy; clinical activity in previous ICI-treated UC was modest. The toxicity profile was consistent with that previously reported for the combination.