Astellas and Seagen Announce Initial Results of PADCEV® (enfortumab vedotin-ejfv) in Patients with Muscle-Invasive Bladder Cancer Not Eligible for Cisplatin Chemotherapy

– Late-breaking data from Cohort H of EV-103 trial to be presented at the 2022 ASCO Genitourinary Cancers Symposium –
– Activity, tolerability of enfortumab vedotin support ongoing investigation in Phase 3 trials –

Reno, Nevada ( -- Astellas Pharma Inc. and Seagen Inc. announced the initial results from Cohort H of the EV-103 trial investigating PADCEV® (enfortumab vedotin-ejfv) as a monotherapy in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin-based chemotherapy. Data from this late-breaking abstract will be included in an oral presentation (Abstract 435) at the 2022 ASCO Genitourinary Cancers Symposium (ASCO GU) on February 18.

MIBC is a stage of bladder cancer signified by the tumor spreading into the muscle of the bladder wall. Treatment for MIBC typically combines cisplatin-based chemotherapy with radical cystectomy, or removal of the bladder, as well as pelvic lymph node dissection. Cohort H of the Phase 1b/2 EV-103 trial enrolled patients with MIBC who were eligible for surgical treatment, but ineligible for cisplatin-based chemotherapy. Patients received three cycles of neoadjuvant (prior to surgery) enfortumab vedotin on days one and eight of every three-week cycle.

Results from the preliminary analysis of 22 patients showed 36.4% had a pathologic complete response, the primary endpoint, displaying no signs of cancer upon microscopic examination of tissue cells removed during surgery. Half (50%) of all patients had a pathological downstaging, or reduction in tumor size, a secondary endpoint of the trial. All patients underwent surgery, and no surgeries were delayed following treatment with enfortumab vedotin. The most common (≥20%) adverse events (AEs) related to treatment with enfortumab vedotin were fatigue (45.5%), alopecia (36.4%), dysgeusia (36.4%), diarrhea (27.3%), nausea (27.3%), peripheral sensory neuropathy (27.3%), dry eye (22.7%) and rash maculopapular (22.7%), consistent with the known safety profile of enfortumab vedotin.

Please see Important Safety Information, including BOXED WARNING, at the end of this press release for further safety information regarding enfortumab vedotin.

“Neoadjuvant cisplatin-based chemotherapy, which is intended to shrink tumors prior to surgery, prolongs survival in patients with MIBC. However, up to half of these patients with MIBC are ineligible for cisplatin treatment and typically must undergo surgery without that treatment,” said Ahsan Arozullah, M.D., M.P.H., Vice President, Medical Sciences-Oncology, Astellas.
“Results from EV-103 Cohort H showed that, when patients received enfortumab vedotin prior to surgery, more than one-third displayed no evidence of cancer when their bladder was removed and examined microscopically for residual tumors,” said Daniel Petrylak, M.D., Yale School of Medicine Professor of Medicine (Medical Oncology) and of Urology, Co-Leader, Cancer Signaling Networks, Yale Cancer Center, and principal investigator for EV-103 Cohort H. “After treatment with enfortumab vedotin, all patients proceeded to surgery. Given there is no standard of care for neoadjuvant treatment in cisplatin-ineligible patients, these results are important and support further research.”

“The initial findings from EV-103 Cohort H are encouraging, and we look forward to learning more from the Phase 3 studies evaluating enfortumab vedotin in muscle-invasive bladder cancer in combination with the anti-PD-1 therapy pembrolizumab,” said Marjorie Green, M.D., Senior Vice President and Head of Late-Stage Development at Seagen.

In addition to this trial, enfortumab vedotin is being investigated as a monotherapy and in combination with other therapies in clinical trials across lines of treatment and stages of bladder cancer.

Astellas and Seagen will also present updates from the broader enfortumab vedotin program in four posters at ASCO GU 2022, including:

  • EV-302: A 2-arm, open-label, randomized controlled phase 3 trial of enfortumab vedotin in combination with pembrolizumab vs chemotherapy in previously untreated advanced urothelial carcinoma (aUC) (Trial in Progress) (Abstract TPS589)
  • EV-103 Cohort L: Evaluating perioperative enfortumab vedotin monotherapy in cis-ineligible muscle invasive bladder cancer (MIBC) (Trial in Progress) (Abstract TPS587)
  • Clinical pharmacology of the antibody-drug conjugate enfortumab vedotin in advanced urothelial carcinoma and other malignant solid tumors (Abstract 568)
  • Systematic literature review (SLR) and network meta-analysis (NMA) of first-line therapies (1L) for locally advanced/metastatic urothelial carcinoma (la/mUC) (Abstract 570)

Source: "News | Astellas Pharma Inc.". 2022. Astellas.Com.