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

Gage Wolfe, left, a senior at Arlington High School and Logan Gardner, right, a senior at Marysville Pilchuck High School work with their team to construct wooden framed walls, copper plumbing, electrical circuits and a brick facade on Tuesday, Feb. 10, 2026 in Marysville, Washington. (Olivia Vanni / The Herald)
High schoolers construct, compete and get career-ready

In Marysville, career technical education students showed off all they’d learned at the SkillsUSA Teamworks Competition.

The Edmonds City Council on Tuesday, Jan. 6 in Edmonds, Washington. (Will Geschke / The Herald)
Edmonds issues moratorium on development in Deer Creek aquifer

The ordinance passed unanimously Tuesday, giving the city time to complete a study on PFAS in the area.

Taylor Scott Richmond / The Herald
Getchell High School students protest ICE during their walkout demonstration on Wednesday in Marysville.
Marysville students peacefully protest ICE

Around 150 Getchell High School students walked out of school to line 67th Avenue Northeast as cars drove by on Wednesday morning.

Logo for news use featuring Snohomish County, Washington. 220118
Snohomish County voters continue to approve most school levies, bonds

The Monroe School District operations levy, which was failing after initial results, was passing Thursday with 50.4% of the vote.

People fish from the pier, hold hands on the beach and steer a swamped canoe in the water as the sun sets on another day at Kayak Point on Monday, June 12, 2023, in Stanwood, Washington. (Ryan Berry / The Herald)
Kayak Point Park construction to resume

Improvements began in 2023, with phase one completed in 2024. Phase two will begin on Feb. 17.

Everett
Everett to pilot new districtwide neighborhood meetings

Neighborhoods will still hold regular meetings, but regular visits from the mayor, city council members and police chief will take place at larger districtwide events.

A truck drives west along Casino Road past a new speed camera set up near Horizon Elementary on Wednesday, May 8, 2024 in Everett, Washington. (Olivia Vanni / The Herald)
Crashes, speeding down near Everett traffic cameras

Data shared by the city showed that crashes have declined near its red light cameras and speeds have decreased near its speeding cameras.

Community Transit is considering buying the Goodwill Outlet on Casino Road, shown here on Tuesday, Jan. 6, 2026 in Everett, Washington. (Will Geschke / The Herald)
Community Transit to pay $25.4M for Everett Goodwill property

The south Everett Goodwill outlet will remain open for three more years per a proposed lease agreement.

Logo for news use featuring Snohomish County, Washington. 220118
Parent support collaborative worries money will run out

If funding runs out, Homeward House won’t be able to support parents facing drug use disorders and poverty.

Carlos Cerrato, owner of Taqueria El Coyote, outside of his food truck on Thursday, Jan. 29, 2026 in Lynnwood. (Olivia Vanni / The Herald)
Everett proposes law to help close unpermitted food carts

The ordinance would make it a misdemeanor to operate food stands without a permit, in an attempt to curb the spread of the stands officials say can be dangerous.

Megan Wolfe, the executive director of the Snohomish County’s Girls on the Run, at her office on Thursday, Feb. 12, 2026 in Mountlake Terrace, Washington. (Olivia Vanni / The Herald)
SnoCo nonprofit teaches running and life skills simultaneously

Girls on the Run hopes to teach students confidence and people skills while getting them to be active.

Arlington
Man convicted of manslaughter after stabbing death of his friend on a camping trip

The third trial for Alexander Vanags, of Arlington, came to a close Thursday after five weeks in Whatcom County Superior Court.

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.