Pfizer to acquire Seagen for $43bn in biggest pharma transaction since 2019

Pfizer has announced that it will acquire Seagen for a total enterprise value of $43bn, which will be a significant boost to the US pharma’s oncology pipeline.

Under the terms of the agreement, which marks the biggest pharma deal since AbbVie agreed to acquire Allergan for $63bn in 2019, Pfizer will pay $229 in cash per Seagen share, a 32.7% premium to last Friday's closing price.

Dr Albert Bourla, chairman and chief executive officer of Pfizer, said: “[The company is] deploying its financial resources to advance the battle against cancer, a leading cause of death worldwide with a significant impact on public health.

"Oncology continues to be the largest growth driver in global medicine, and this acquisition will enhance Pfizer’s position in this important space and contribute meaningfully to the achievement of Pfizer’s near- and long-term financial goals.”

Pfizer's oncology portfolio currently includes 24 approved drugs, while Seagen's includes Adcetris for lymphomas, Padcev for bladder cancers, Tivdak for cervical cancer, and Tukysa for breast and colorectal cancers.

As well as the four approved medicines, which are all currently being assessed for potential new tumour types or expanded indications, Pfizer will also gain access to Seagen’s drug development pipeline and have the option to explore combinations across its own pipeline.

The deal also includes Seagen’s proprietary antibody-drug conjugate (ADC) technology, Pfizer said.

Unlike chemotherapy, which works by attacking lots of different cells as well as the cancer, ADCs are designed to target and kill tumour cells while sparing healthy cells.

Chris Boshoff, chief development officer, oncology and rare disease at Pfizer, said: “The addition of Seagen’s world-leading ADC technology will position us at the forefront of innovative cancer care, and strongly complements our existing portfolio across both solid tumours and haematologic malignancies.”

The companies expect to complete the transaction in late 2023 or early 2024.

David Epstein, Seagen’s chief executive officer, said: “The proposed combination with Pfizer is the right next step for Seagen to further its strategy, and this compelling transaction will deliver significant and immediate value to our stockholders and provide new opportunities for our colleagues as part of a larger science-driven, patient-centric, global company.”