Clay Siegall in 2018. (Dan Bates / The Herald)

Clay Siegall in 2018. (Dan Bates / The Herald)

Ex-Seagen CEO to return to Bothell to lead newly relocated biotech firm

Clay Siegall, who resigned from Seagen over allegations of domestic abuse, is now CEO of cancer therapy developer Immunome.

BOTHELL — Clay Siegall, the former CEO of Seagen who resigned last year over allegations of domestic abuse, will return to the area as chief executive of Immunome, a Pennsylvania-based biotech company that’s moving its headquarters to Bothell.

In April 2022, Siegall was arrested on suspicion of misdemeanor domestic violence after his now-former wife called police. She reported Siegall had physically assaulted and injured her, resulting in bruises, a cut and a sprained wrist.

Siegall denied the allegations but resigned his post at Seagen, the Bothell biotech he co-founded in 1997.

The Edmonds city prosecutor declined to bring charges, citing inconsistent and contradictory statements about what happened.

In March of this year, Siegall joined Morphimmune, a privately-owned Indiana biotech, as president and CEO. Morphimmune recently merged with Immunome, a Philadelphia-area company developing targeted cancer therapies.

As part of the deal, Siegall was named CEO, president and board chairman of the combined company, operating as Immunome. The public company trades on the Nasdaq under the symbol, IMNM.

“Clay Siegall’s track record of drug development and shareholder value creation is exceptional, and we are honored to have him serve as chairman and CEO after the merger closes,” Michael Rapp, Immunome board chairman, said in a statement in June announcing the merger.

The merger was completed in October.

“Under his nearly 25 years of leadership, Seagen became the world leader in ADC (targeted cancer) therapeutics, earned Federal Drug Administration approvals for four cancer therapies, and grew to over $2 billion in annual revenue,” Immunome said of Siegall.

The terms of merger also includes a move to the Seattle area.

Immunome is moving its headquarters from Philadelphia to Alloy Innovation Center in Bothell, according to The Registry, a commercial real estate news outlet. The company will maintain research facilities in Pennsylvania and Indiana.

In a statement, Siegall described the merger as “the first step in establishing a preeminent oncology company,” and added, “Given the quality of our science, the expertise of our combined leadership team, and the strengthened cash position, I am extremely enthusiastic about our potential to reduce the suffering and loss of life caused by cancer,” he said.

As head of Seagen, Siegall was one of the highest paid chief executives in the state. 

Siegall made $19 million in salary and compensation in 2021, according to documents filed with the U.S. Securities and Exchange Commission. Meanwhile, Seagen had revenue of $1.6 billion. Its therapies are used to treat Hodgkin lymphoma and bladder, breast and cervical cancers. Pfizer finalized the acquisition of Seagen this month for $43 billion.

In 2018, Economic Alliance Snohomish County presented Siegall with the John M. Fluke award, given to an “individual who has demonstrated entrepreneurial spirit, and community leadership.” Established in 1970, the award is named after the founder of the Fluke Corp.

Siegall was a pre-med college student planning to become a doctor when his father was diagnosed with cancer, according to a 2018 report in The Daily Herald.

“When you’re 19 years old and your father is diagnosed with a cancer that would ultimately take his life, there’s a lot of changes going on at that point,” he said. “I got really interested in how cancer therapies are made.”

He founded Seattle Genetics in 1997. In 2020, the company changed its name to Seagen.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Logo for news use featuring the municipality of Monroe in Snohomish County, Washington. 220118
U.S. 2 closed east of Monroe for two-car fatality collision

Troopers are on the scene investigating as of 7 p.m. Saturday

Traffic moves along Bowdoin Way past Yost Park on Monday, Aug. 25, 2025 in Edmonds, Washington. (Olivia Vanni / The Herald)
A new online tool could aid in local planning to increase tree coverage

The map, created by Washington Department of Natural Resources and conservation nonprofit American Forests, illustrates tree canopy disparities across the state.

Logo for news use featuring Snohomish County, Washington. 220118
Snohomish PUD preps for more state home electrification funding

The district’s home electrification rebate program distributed over 14,000 appliances last year with Climate Commitment funds.

Logo for news use featuring the municipality of Everett in Snohomish County, Washington. 220118
One person dead in single-vehicle crash on Wednesday in Everett

One man died in a single-vehicle crash early Wednesday morning… Continue reading

A firefighter moves hazard fuel while working on the Bear Gulch fire this summer. Many in the wildland fire community believe the leadership team managing the fire sent crews into an ambush by federal immigration agents. (Facebook/Bear Gulch Fire 2025)
Firefighters question leaders’ role in Washington immigration raid

Wildfire veterans believe top officials on the fire sent their crews into an ambush.

More frequent service coming for Community Transit buses

As part of a regular update to its service hours, the agency will boost the frequencies of its Swift lines and other popular routes.

More than $1 million is available for housing-related programs in Snohomish County, and the Human Services Department is seeking applications. (File photo)
Applicants sought for housing programs in Snohomish County

More than $1 million is available for housing-related programs in… Continue reading

Anfissa Sokolova, M.D., demonstrates how to use the training tools on the Da Vinci Xi Surgical System on Wednesday, Sept. 3, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
Getting surgery in Everett? Robots might be helping.

Recent advancements in robotic-assisted surgery have made procedures safer and easier on patients, local surgeons said.

Provided photo
Harrison Edell speaks at the PAWS Companion Animal Shelter in Lynnwood.
Lynnwood’s PAWS animal organization has a new CEO

Harrison Edell was appointed to lead the nonprofit after the board approved new strategic objectives.

The boardwalk at Scriber Lake Park on Wednesday, June 4, 2025 in Lynnwood, Washington. (Olivia Vanni / The Herald)
Outdoor author Ken Wilcox rounds up fall hiking recommendations

From Lynnwood’s renovated Scriber Lake boardwalk to the summit of Mt. Pilchuck, there are hikes galore to admire the fall scenery.

Provided photo
Snohomish County Auditor Garth Fell (middle left) and Elections division staff stand with the “Independence Award” from the National Association of Election Officials.
Snohomish County Elections awarded for “outstanding service”

The National Association of Election Officials recognized the department’s 2024 “Elections Explained” initiative.

Fake Edmonds police detective arrested in Bremerton on Friday

Man allegedly arrived at an active police scene in police gear and a Ford Explorer with activated police lights, police say

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.