Astellas and Seagen Announce Positive Topline Results For PADCEV® (enfortumab vedotin-ejfv) with KEYTRUDA® (pembrolizumab) as First-Line Treatment for Advanced Urothelial Cancer

– Companies plan to discuss results with regulatory authorities –

TOKYO, Japan and BOTHELL, WA, USA I July 26, 2022 I Astellas Pharma Inc. (TSE:4503, President and CEO: Kenji Yasukawa, Ph.D., "Astellas") and Seagen Inc. (Nasdaq:SGEN) today announced positive topline results from the phase 1b/2 EV-103 clinical trial (also known as KEYNOTE-869) Cohort K evaluating PADCEV® (enfortumab vedotin-ejfv) in combination with Merck's anti-PD-1 therapy KEYTRUDA® (pembrolizumab) as first-line treatment in patients with unresectable locally advanced or metastatic urothelial cancer (la/mUC) who are ineligible to receive cisplatin-based chemotherapy. Merck is known as MSD outside the United States and Canada.

In patients treated with enfortumab vedotin and pembrolizumab, results demonstrated a 64.5% confirmed objective response rate (ORR) (95% CI: 52.7 to 75.1) per blinded independent central review (BICR), the primary endpoint of Cohort K. The median duration of response (DOR) per BICR was not reached. The most frequently reported treatment-emergent adverse events Grade 3 or greater that occurred in more than 5% of patients were rash maculo-papular, anemia, lipase increased, urinary tract infection, hyperglycemia, fatigue, neutropenia, hematuria, diarrhea, acute kidney injury, hyponatremia, chronic kidney disease, weight decreased, syncope, hypophosphatemia, pneumonitis, sepsis, and alanine aminotransferase increased. Overall, the results are generally consistent with previously reported efficacy and safety results of the EV-103 dose-escalation cohort and expansion Cohort A.1 Additional Cohort K results will be reported at an upcoming scientific congress.

EV-103 Cohort K is a randomized cohort investigating enfortumab vedotin alone or in combination with pembrolizumab as first-line treatment in patients with unresectable la/mUC who are ineligible to receive cisplatin-based chemotherapy. Secondary endpoints include ORR per investigator assessment; DOR, disease control rate and progression-free survival per BICR and investigator assessment; overall survival; and assessment of safety.

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

"Approximately half of patients with advanced urothelial carcinoma are ineligible for cisplatin-based chemotherapy," said Ahsan Arozullah, M.D., M.P.H., Senior Vice President and Head of Development Therapeutic Areas, Astellas. "We intend to discuss Cohort K results with regulatory authorities as we seek to develop a new first-line treatment combination for these patients."

"We are encouraged by the positive topline results of Cohort K for the combination of enfortumab vedotin and pembrolizumab in first-line locally advanced or metastatic urothelial cancer, and we look forward to sharing results at an upcoming medical meeting," said Roger Dansey, M.D., interim CEO and Chief Medical Officer, Seagen.

Astellas, Seagen and Merck are investigating enfortumab vedotin plus pembrolizumab as part of an extensive collaboration, which also includes three Phase 3 studies: the EV-302/KEYNOTE-A39 trial intended to confirm these results, as well as EV-304/KEYNOTE-B15 and EV-303/KEYNOTE-905 in muscle-invasive bladder cancer.

In February 2020, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation for enfortumab vedotin in combination with pembrolizumab for patients with unresectable la/mUC who are ineligible to receive cisplatin-based chemotherapy in the first-line setting. The designation is based on results from the dose-escalation cohort and expansion Cohort A of the phase 1b/2 trial, EV-103 (NCT03288545), evaluating patients with la/mUC who are ineligible to receive cisplatin-based chemotherapy treated in the first-line setting with enfortumab vedotin in combination with pembrolizumab.

About Bladder and Urothelial Cancer
It is estimated that approximately 83,730 people in the U.S. were diagnosed with bladder cancer in 2021.2 Urothelial cancer accounts for 90% of all bladder cancers and can also be found in the renal pelvis, ureter and urethra.3 Globally, approximately 573,000 new cases of bladder cancer and 212,000 deaths are reported annually.4

About the EV-103 Trial (Cohort K)
The EV-103 trial (NCT03288545) is an ongoing, multi-cohort, open-label, multicenter phase 1b/2 trial of enfortumab vedotin alone or in combination with pembrolizumab and/or chemotherapy in first- or second-line settings in patients with locally advanced or metastatic urothelial cancer (la/mUC) and in patients with muscle-invasive bladder cancer.

Cohort K of the EV-103 trial is investigating enfortumab vedotin alone (n=73) or in combination with pembrolizumab (n=76) in adult patients with unresectable la/mUC who are ineligible for cisplatin-based chemotherapy and have received no prior treatment for la/mUC. The enfortumab vedotin monotherapy study arm is intended to characterize the activity of enfortumab vedotin alone in this patient population. Key outcome measures of EV-103 Cohort K are objective response rate (ORR) per blinded independent central review (BICR) using RECIST 1.1 and assessment of safety.

PADCEV (enfortumab vedotin-ejfv) is a first-in-class antibody-drug conjugate (ADC) that is directed against Nectin-4, a protein located on the surface of cells and highly expressed in bladder cancer.5 Nonclinical data suggest the anticancer activity of PADCEV is due to its binding to Nectin-4 expressing cells followed by the internalization and release of the anti-tumor agent monomethyl auristatin E (MMAE) into the cell, which result in the cell not reproducing (cell cycle arrest) and in programmed cell death (apoptosis).6

PADCEV (enfortumab vedotin-ejfv) U.S. Indication & Important Safety Information


  • PADCEV can cause severe and fatal cutaneous adverse reactions including Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN), which occurred predominantly during the first cycle of treatment, but may occur later.
  • Closely monitor patients for skin reactions.
  • Immediately withhold PADCEV and consider referral for specialized care for suspected SJS or TEN or severe skin reactions.
  • Permanently discontinue PADCEV in patients with confirmed SJS or TEN; or Grade 4 or recurrent Grade 3 skin reactions.


PADCEV® is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer (mUC) who:

  • have previously received a programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor and platinum-containing chemotherapy, or
  • are ineligible for cisplatin-containing chemotherapy and have previously received one or more prior lines of therapy.5

For more information, please see the full Prescribing Information including BOXED WARNING for PADCEV here

About Astellas
Astellas Pharma Inc. is a pharmaceutical company conducting business in more than 70 countries around the world. We are promoting the Focus Area Approach that is designed to identify opportunities for the continuous creation of new drugs to address diseases with high unmet medical needs by focusing on Biology and Modality. Furthermore, we are also looking beyond our foundational Rx focus to create Rx+® healthcare solutions that combine our expertise and knowledge with cutting-edge technology in different fields of external partners. Through these efforts, Astellas stands on the forefront of healthcare change to turn innovative science into value for patients. For more information, please visit our website at

About Seagen
Seagen Inc. is a global biotechnology company that discovers, develops and commercializes transformative cancer medicines to make a meaningful difference in people's lives. Seagen is headquartered in the Seattle, Washington area, and has locations in California, Canada, Switzerland and the European Union. For more information on the company's marketed products and robust pipeline, visit and follow @SeagenGlobal on Twitter. 

About the Astellas, Seagen and Merck Collaboration
Astellas and Seagen entered a clinical collaboration agreement with Merck to evaluate the combination of Astellas' and Seagen's PADCEV® (enfortumab vedotin-ejfv) and Merck's KEYTRUDA® (pembrolizumab) in patients with previously untreated metastatic urothelial cancer. KEYTRUDA is a registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

Astellas Cautionary Notes
In this press release, statements made with respect to current plans, estimates, strategies and beliefs and other statements that are not historical facts are forward-looking statements about the future performance of Astellas. These statements are based on management's current assumptions and beliefs in light of the information currently available to it and involve known and unknown risks and uncertainties. A number of factors could cause actual results to differ materially from those discussed in the forward-looking statements. Such factors include, but are not limited to: (i) changes in general economic conditions and in laws and regulations, relating to pharmaceutical markets, (ii) currency exchange rate fluctuations, (iii) delays in new product launches, (iv) the inability of Astellas to market existing and new products effectively, (v) the inability of Astellas to continue to effectively research and develop products accepted by customers in highly competitive markets, and (vi) infringements of Astellas' intellectual property rights by third parties.

Information about pharmaceutical products (including products currently in development), which is included in this press release, is not intended to constitute an advertisement or medical advice.

1 C.J. Hoimes, J.E. Rosenberg EV-103: Initial results of enfortumab vedotin plus pembrolizumab for locally advanced or metastatic urothelial carcinoma. Annals of Oncology 30 (Supplement 5): v356–v402, 2019.
2 American Cancer Society. Cancer Facts & Figures 2021. Accessed July 25, 2022.
3 American Society of Clinical Oncology. Bladder cancer: introduction (9-20). Accessed July 25, 2022.
4 International Agency for Research on Cancer. Cancer Tomorrow: Bladder. Accessed July 25, 2022.
5 Challita-Eid P, Satpayev D, Yang P, et al. Enfortumab Vedotin Antibody-Drug Conjugate Targeting Nectin-4 Is a Highly Potent Therapeutic Agent in Multiple Preclinical Cancer Models. Cancer Res 2016;76(10):3003-13.
6 PADCEV [package insert]. Northbrook, IL: Astellas Pharma US, Inc.

SOURCE: Astellas Pharma

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