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Treatment with the combination of the first-in-class Bicycle drug conjugate (BDC) zelenectide pevedotin (BT8009) and pembrolizumab (Keytruda) was safe and generated antitumor activity in patients with previously untreated, cisplatin-ineligible, locally advanced or metastatic urothelial carcinoma, according to data from the phase 1/2 Duravelo-1 trial (NCT04561362).
Findings presented at the 2025 ASCO Annual Meeting showed that at a median follow-up of 7.1 months (range, 1.0-13.2), evaluable patients treated with the combination (n = 20) achieved an overall response rate (ORR) of 65.0% (95% CI, 40.8%-84.6%), comprising a complete response rate of 25.0% and a partial response rate of 40.0%. The stable disease rate was 25.0%, and the disease control rate (DCR) was 90.0%. Duration of response (DOR) data were not mature.
Regarding safety, any-grade treatment-emergent adverse effects (TEAEs) occurred in all patients (n = 22), and 72.7% experienced grade 3 or higher TEAEs. Treatment-related AEs (TRAEs) of any grade were reported in all patients, including 68.2% who had grade 3 or higher TRAEs. Any-grade and grade 3 or higher zelenectide pevedotin–related TRAEs occurred at rates of 90.9% and 59.1%, respectively. These rates were 95.5% and 50.0%, respectively, for pembrolizumab.
Serious AEs were reported in 54.5% of patients, including 50.0% who had grade 3 or higher serious AEs. TEAEs led to dose reductions and dose discontinuations of zelenectide pevedotin in 50.0% and 4.5% of patients, respectively. These rates were 0% and 9.1%, respectively, for pembrolizumab.
“These data support a randomized, multicenter, open-label, phase 2/3 trial [NCT06225596] of zelenectide pevedotin as monotherapy and in combination with pembrolizumab vs chemotherapy in patients with locally advanced/metastatic urothelial cancer,” lead study author Patrizia Giannatempo, MD, of Fondazione IRCCS – Istituto Nazionale dei Tumori in Milan, Italy, and colleagues wrote in a poster presentation of the data.
Zelenectide Pevedotin and Duravelo-1 Background
Zelenectide pevedotin features a highly selective Nectin-4–targeting bicyclic peptide that is conjugated to a monomethyl auristatin E payload via a cleavable link. Bicycle molecules have the manufacturing and pharmacokinetic properties of small molecules with the high binding specificity of a biologic agent.
Duravelo-1 enrolled adult patients with locally advanced or metastatic urothelial carcinoma who were ineligible for cisplatin per Galsky criteria and were naive to systemic therapy in the advanced setting. Patients needed to meet at least 1 of the following criteria to be deemed ineligible for cisplatin:
- a creatinine clearance of 30 to 59 mL per minute
- hearing loss of at least 25 decibels at 2 contiguous frequencies
- New York Heart Association heart failure of class III or higher
- an ECOG performance status of 2, with a hemoglobin level of at least 10 g/dL, a creatinine clearance of at least 50 mL per minute, and no NYHA class III heart failure
The study evaluated zelenectide pevedotin as monotherapy and in combination with pembrolizumab. For the combination, zelenectide pevedotin was given at 5 mg/m2 on days 1, 8, and 15 of each 21-day cycle, and pembrolizumab was administered at 200 mg on day 1 of each cycle.
The trial’s primary end point was investigator-assessed ORR per RECIST 1.1 criteria. Safety, DOR, and DCR were secondary end points.
As of the January 3, 2025, data cutoff, patients in the combination cohort (n = 22) had a median age of 77 years (range, 61-85). The majority were male (68.2%) and White (81.8%). Patients had an ECOG performance status of 0 (22.7%), 1 (31.8%), or 2 (45.5%). Baseline creatinine clearance was below 60 mL per minute for 54.5% of patients.
Additional Safety Findings
Grade 4 TRAEs of hypomagnesemia and neutropenia were each reported in 1 patient. No grade 5 TRAEs occurred.
The most common TRAEs reported in at least 20% of patients given the combination included asthenia (any-grade, 63.6%; grade ≥3, 9.1%), anemia (59.1%; 0%), diarrhea (50.0%; 9.1%), decreased appetite (40.9%; 4.5%), increased aspartate aminotransferase levels (36.4%; 4.5%), nausea (36.4%; 4.5%), rash (31.8%; 4.5%), increased alanine aminotransferase levels (27.3%; 13.6%), neutropenia (27.3%; 13.6%), pruritus (27.3%; 0%), alopecia (22.7%; 0%), hyperglycemia (22.7%; 0%), and vomiting (22.7%; 4.5%).
Reference
Giannatempo P, Galsky M, Duran I, et al. Phase 1/2 Duravelo-1 study: Preliminary results of nectin-4–targeting zelenectide pevedotin (BT8009) plus pembrolizumab in previously untreated, cisplatin-ineligible patients with locally advanced or metastatic urothelial cancer. J Clin Oncol. 2025;43(suppl 16):4567. doi:10.1200/JCO.2025.43.16_suppl.4567