medwireNews: Durability and survival results from the phase 1b EV-103 trial provide further support for the combination of enfortumab vedotin and pembrolizumab as a promising first-line option for patients with cisplatin-ineligible locally advanced or metastatic urothelial carcinoma.
Speaking at the 2020 Genitourinary Cancers Symposium in San Francisco, California, USA, Jonathan Rosenberg (Memorial Sloan Kettering Cancer Center, New York, USA) said that the initial results from this trial – presented previously at the ESMO Congress 2019 – “showed very promising activity in terms of objective response rates [ORR], suggesting that a potential platinum free approach in this patient population is warranted.”
In the updated analysis, with a median follow-up of 10.4 months, Rosenberg reported that 93.0% of the 45 patients treated with enfortumab vedotin 1.25 mg/kg on days 1 and 8 plus pembrolizumab 200 mg on day 1 of each 3-week cycle had “at least some degree of tumor reduction,” while the ORR was 73.3% and the complete response rate was 15.6%.
The presenter said that “responses were rapid” and “appeared durable,” with 88.0% of responses seen at the first imaging assessment around week 9, and many patients continuing treatment beyond the 1-year follow-up.
Jonathan Rosenberg provides an update on the EV-103 trial of enfortumab vedotin plus pembrolizumab for cisplatin-ineligible advanced urothelial carcinoma (3:40).
At the time of analysis, the median duration of response was not reached, and 53.7% of participants had a response lasting at least 1 year.
Survival data in the updated analysis were “encouraging,” Rosenberg told delegates, noting that the median duration of progression-free survival was 12.3 months, “which is quite long in this patient population,” while the median duration of overall survival was not yet reached at the time of analysis. The 1-year rates of progression-free and overall survival were 50.1% and 81.6%, respectively.
In all, 16.0% (n=7) of participants experienced serious treatment-related adverse events (TRAEs), of which all but one resolved. There was one treatment-related death due to multiple organ dysfunction syndrome. Six patients discontinued treatment due to TRAEs, most commonly as a result of peripheral sensory neuropathy, given as the reason for discontinuation in three patients.
The TRAE profile was “similar, as you might expect, [to that seen with] monotherapy with each of these agents,” and “no new safety signals were seen with the combination,” said Rosenberg, adding that the combination had a “stable safety profile over time.”
Taken together, the updated EV-103 results show that further investigation of enfortumab vedotin plus pembrolizumab “is warranted in patients with untreated locally advanced or metastatic urothelial cancer,” concluded Rosenberg.
And he told the audience that “a pivotal phase III study, EV-302, is about to activate, which will evaluate enfortumab vedotin plus pembrolizumab in combination either with chemotherapy or without chemotherapy versus standard chemotherapy in patients in this setting.”
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2020 Genitourinary Cancers Symposium; San Francisco, California, USA: 13–15 February