JPM24: Even after Seagen buyout, Pfizer oncology chief still eyes ADC deals

San FranciscoDespite its recent $43 billion acquisition of Seagen, Pfizer is still on the lookout for deals centered on antibody-drug conjugates (ADCs).

“Building a world-class oncology organization, we obviously want to continue to make sure we not only compare the best opportunities internally but also externally,” Pfizer’s newly minted chief oncology officer, Chris Boshoff, Ph.D., said in an interview on the sidelines of the J.P. Morgan Healthcare Conference.

The company is “looking at opportunities from companies in the Far East now, and certainly also companies in China, which is important in this whole area, especially ADC development,” Boshoff added.

After Pfizer closed the Seagen deal in December, word came out that the company put down $53 million in upfront and near-term payments—and up to $1.05 billion in milestones—for a mesothelin-targeted ADC from Nona Biosciences. Nona’s parent, the Chinese antibody specialist Harbour BioMed, designed the med with another Chinese firm called MediLink Therapeutics, which has out-licensed ADCs to Roche and BioNTech.

As a target, mesothelin has seen its fair share of failures, including an ADC that Bayer developed with ImmunoGen—now being acquired by AbbVie—and MorphoSys. Boshoff said the Nona candidate has a unique payload, and that its preclinical data gave Pfizer confidence that the drug deserves further development.

As to whether Pfizer will consider another outright biotech acquisition, Boshoff said: “Of course, we’ll consider it, but also put in the context that we’ve just spent $43 billion. So, we’re not currently looking for big acquisitions.”

Boshoff recently took on a broader remit as Pfizer’s chief oncology officer during a reorganization. Now, the former oncology R&D head has assumed additional commercialization responsibilities and is leading an end-to-end organization.

The Seagen deal was a driver of the restructuring because the ADC biotech brought its own capabilities ranging from discovery to commercialization, Boshoff explained. Seagen nearly doubled the size of Pfizer’s oncology team. Besides Suneet Varma, who leads U.S. oncology commercialization, five of the nine leaders in Boshoff’s unit joined from Seagen.

“The main reason for the new organization is speed and efficiency,” Boshoff said. “How can we accelerate? How can we have fewer hand-offs?”

In his new role, Boshoff is focused on executing on several near-term priorities. These include the launch of Astellas-partnered Padcev, in combination with Merck’s Keytruda, in front-line bladder cancer, as well as the expansion of Astellas-partnered Xtandi as the first androgen receptor inhibitor for high-risk nonmetastatic castration-sensitive prostate cancer. 

“Everything I’ve applied in oncology drug development has always had a business acumen to it,” Boshoff said. “Because I have a deep, deep understanding of the competitive environment and of the standard of care in the future, that has helped me a lot.”

Boshoff touted Pfizer’s commercial footprint in 100 countries, compared with 17 for Seagen. For the Padcev-Keytruda U.S. launch, Pfizer is working with payers to make sure that the combo's overall survival benefit translates into a recognition of the regimen as the new standard of care.

“I’m thinking of a future where bladder cancer won’t be called cisplatin-eligible or cisplatin-ineligible but Padcev-eligible or Padcev-ineligible,” Boshoff said. “I think getting those messages out based on incredible data, that’s very important for patients with advanced metastatic bladder cancer.”

In the pipeline, one asset that Boshoff’s team is “paying close attention to this year” is the integrin beta-6-directed ADC called SGN-B6A, which will deliver early combination data with Keytruda in solid tumors this year. Meanwhile, a phase 3 trial is testing the candidate as a single agent in previously treated non-small cell lung cancer.

Elsewhere in the pipeline, HER2-targeted ADC disitamab vedotin—which Seagen in-licensed from Chinese firm RemeGen—entered phase 3 testing last fall as part of a Keytruda combination in first-line HER2-positive bladder cancer. Pfizer is also looking at potential opportunities for the drug in breast cancer and other tumor types.

Disitamb vedotin, already approved in China, is a differentiated HER2 ADC because it uses a different antibody than AstraZeneca and Daiichi Sankyo’s Enhertu and Roche’s Kadcyla, Boshoff explained.

In breast cancer, Seagen has previously said disitamab vedotin could capture a large market being used after Enhertu because of its different payload. Boshoff said Pfizer will look at more data and plans to make a final strategy decision in breast cancer toward the second half of this year.

As the oncology chief noted, urogenital cancers and breast cancer are two main tumor types that are very important to Pfizer's organization.

For early-stage candidates, Pfizer plans to advance eight novel molecules into first-in-human studies this year, Boshoff said.