Seagen to Highlight Data From Oncology Portfolio and Pipeline at the 2023 American Society of Clinical Oncology Annual Meeting

- Long-term follow-up data for PADCEV® (enfortumab vedotin-ejfv) with KEYTRUDA® (pembrolizumab) in advanced bladder cancer to be featured as oral presentation –

- Updated Phase 1 data on first-in-class integrin beta-6 targeted antibody-drug conjugate (ADC) (SGN-B6A) to be presented –

BOTHELL, Wash.--(BUSINESS WIRE)--Seagen Inc. (Nasdaq: SGEN) today announced the presentation of 17 abstracts at the upcoming 2023 American Society of Clinical Oncology (ASCO) Annual Meeting taking place June 2-6, 2023, in Chicago. Data will be presented across Seagen's portfolio of approved medicines and pipeline agents in a range of cancer types and in earlier lines of therapy.

“Seagen has worked towards revolutionizing cancer care for 25 years by linking scientific innovation to meaningful impacts in patients’ lives,” said Roger Dansey, M.D., President, Research and Development and Chief Medical Officer at Seagen. “Our data presented at ASCO demonstrate continued progress in our efforts to discover and develop transformative medicines.”

Highlights include new data from a robust clinical development program in bladder cancer with trials across multiple lines of treatment and into earlier stages of disease for muscle-invasive and non-muscle invasive forms of bladder cancer. Long-term follow-up data from a clinical trial of PADCEV^® (enfortumab vedotin-ejfv) (EV-103 dose-escalation and Cohort A) will be featured in an oral presentation on Monday, June 5. The EV-103 dose-escalation/Cohort A study is evaluating PADCEV, developed in partnership with Astellas, in combination with Merck’s anti-PD-1 therapy KEYTRUDA^® (pembrolizumab) as first-line treatment in patients with locally advanced or metastatic urothelial carcinoma who are ineligible to receive cisplatin-based chemotherapy. Merck is known as MSD outside the United States and Canada.

Updated Phase 1 data will be presented for SGN-B6A, a wholly-owned, first-in-class vedotin ADC directed to integrin beta-6, a novel target that is highly expressed in multiple solid tumors.

Additionally, initial data will be presented from studies evaluating Seagen’s approved medicines in potential new cancer types. Data from a Phase 2 basket study of TUKYSA^® (tucatinib) and trastuzumab in previously treated HER2-positive metastatic biliary tract cancer will be featured in an oral presentation on Friday, June 2.

Key data presentations for Seagen include:

Presentations of Company-Sponsored Trials

Abstract Title	Abstract #	Presentation Time	Lead Author
Enfortumab Vedotin
Study EV-103 dose escalation/cohort A: Long-term outcome of enfortumab vedotin + pembrolizumab in first-line (1L) cisplatin-ineligible locally advanced or metastatic urothelial carcinoma (la/mUC) with nearly 4 years of follow-up	4505	Oral Monday, June 5 11:30 a.m. - 2:30 p.m. CT	S. Gupta
Enfortumab vedotin in the previously treated advanced head and neck cancer (HNC) cohort of EV-202	6017	Poster Discussion Monday, June 5 1:15 - 4:15 p.m. CT	P. Swiecicki
A first-in-human trial of intravesical enfortumab vedotin (EV), an antibody-drug conjugate (ADC), in patients with non-muscle invasive bladder cancer (NMIBC): Interim results of a phase 1 study (EV-104)	4596	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	A. Kamat
Study EV-103: Neoadjuvant treatment with enfortumab vedotin monotherapy in cisplatin-ineligible patients (pts) with muscle invasive bladder cancer (MIBC): Updated results for Cohort H	4595	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	T. Flaig
Enfortumab vedotin (EV) with or without pembrolizumab (P) in cisplatin-ineligible patients with previously untreated locally advanced or metastatic urothelial cancer (la/mUC): Additional 3-month follow-up on Cohort K data	4568	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	T. Friedlander
EV-203: Phase 2 trial of enfortumab vedotin in patients with previously treated advanced urothelial carcinoma in China	e16574	Online Abstract	Q. Li
Enfortumab Vedotin Trials in Progress
KEYNOTE-905/EV-303: A phase 3 study to evaluate the efficacy and safety of perioperative pembrolizumab or pembrolizumab plus enfortumab vedotin (EV) for muscle-invasive bladder cancer (MIBC) (ENCORE)	TPS4601	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	A. Necchi
Tucatinib
Tucatinib and trastuzumab for previously treated HER2-positive metastatic biliary tract cancer (SGNTUC-019): A phase 2 basket study	4007	Oral Friday, June 2 2:45 - 5:45 p.m. CT	Y. Nakamura
Real-world patient characteristics and treatment patterns associated with tucatinib therapy in patients with HER2+ metastatic breast cancer	1051	Poster Sunday, June 4 8:00 - 11:00 a.m. CT	C. Anders
HER2 testing in the MOUNTAINEER trial: Analysis of treatment response based on central HER2 assessment using IHC/ISH and NGS	3528	Poster Monday, June 5 8:00 - 11:00 a.m. CT	J. Strickler
Tucatinib Trials in Progress
HER2CLIMB-05: Phase 3 study of tucatinib or placebo in combination with trastuzumab and pertuzumab as maintenance therapy for HER2+ metastatic breast cancer (trial in progress)	TPS1115	Poster Sunday, June 4 8:00 - 11:00 a.m. CT	E. Hamilton
MOUNTAINEER-03: Phase 3 study of tucatinib, trastuzumab, and modified FOLFOX6 as first line treatment in HER2+ metastatic colorectal cancer (trial in progress)	TPS3631	Poster Monday, June 5 8:00 - 11:00 a.m. CT	T. Bekaii-Saab
Early-Stage/Pipeline
SGN-B6A, an integrin beta-6 (ITGB6)-targeted antibody-drug conjugate (ADC), in patients with advanced solid tumors: Updated results from a phase 1 study (SGNB6A-001)	3024	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	A. Hollebecque
Early-Stage/Pipeline Trials in Progress
Phase 1 study of SGN-BB228, an investigational CD228 x 4-1BB costimulatory antibody anticalin bispecific, in patients with advanced melanoma and other solid tumors (SGNBB228-001: trial in progress)	TPS9597	Poster Saturday, June 3 1:15 - 4:15 p.m. CT	J. Henry

Presentations of Investigator-Sponsored Trials

Abstract Title	Abstract #	Presentation Time	Lead Author
Enfortumab Vedotin
Real-world use, dose intensity, and adherence to an antibody-drug conjugate (ADC) in metastatic urothelial cancer (mUC)	e16567	Online Abstract	R. Mamtani
Tucatinib
UCLA B-13: A phase 1b trial evaluating the safety of ribociclib, tucatinib, and trastuzumab in patients with metastatic, HER2+ breast cancer and a multicenter, randomized, open-label, phase 2 study of preoperative treatment with ribociclib, trastuzumab, tucatinib, with or without fulvestrant versus docetaxel, carboplatin, trastuzumab, and pertuzumab in HR+/HR-, HER2+ breast cancer	TPS1116	Poster Sunday, June 4 8:00 - 11:00 a.m. CT	N. McAndrew
Disitamab Vedotin
Disitamab vedotin, a novel humanized anti-HER2 antibody-drug conjugate (ADC) combined with toripalimab in patients with locally advanced or metastatic urothelial carcinoma: an open-label phase 1b/2 study	4566	Poster Saturday, June 3 8:00 - 11:00 a.m. CT	X. Sheng

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 our marketed products and robust pipeline, visit www.seagen.com and follow @SeagenGlobal on Twitter.

Forward-Looking Statements

Certain statements made in this press release are forward looking, such as those, among others, relating to the therapeutic potential of PADCEV^® (enfortumab vedotin-ejfv), TUKYSA^® (tucatinib), disitamab vedotin, and the company’s other products and product candidates, including their potential efficacy, safety and therapeutic uses, and Seagen’s pipeline. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include without limitation the difficulty and uncertainty of pharmaceutical product development, including the risks that the company may experience delays in its clinical trials or otherwise experience failures or setbacks in its clinical development programs due to lack of efficacy, adverse events or other factors, and that adverse regulatory actions may occur. More information about the risks and uncertainties faced by Seagen is contained under the caption “Risk Factors” included in the company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the Securities and Exchange Commission. Seagen disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.