Japanese firm Daiichi wants to go alone in search of targeted cancer drugs

By Ashleigh Furlong
 

The Japanese cancer drug powerhouse Daiichi Sankyo Co. has its sights on the next generation of targeted oncology drugs, and this time it might not need a partner to get it over the line. 
 

“We’re in a place now where we’ve got a lot of the capabilities that we didn’t have five years ago, so I think the bar for us to consider bringing in a partner gets higher and higher,” Ken Keller, chief executive officer of Daiichi’s’ US subsidiary, said in an interview at the European Society for Medical Oncology.

AstraZeneca Plc and Daiichi’s breast cancer drug Enhertu is based off of Daiichi’s antibody-drug conjugate platform DXd, and was the top-selling ADC globally in 2023. 

ADCs are targeted cancer drugs that in recent years have become some of the most promising treatments for everything from breast to lung cancers. 

They work by ferrying the active ingredient directly to the cancer cells and spare healthy ones. ADCs have been transformative for many patients and investors are betting on Daiichi’s continued success, with its share price up 122 per cent in the last five years. 

Drugmakers like Daiichi and Roche Holding AG have reaped the benefits from ADCs, and they are seeing more competition. Last year, Pfizer Inc. bought ADC heavyweight Seagen Inc. for $43 billion after AbbVie Inc. acquired ImmunoGen Inc. for $10.1 billion to secure its ADC drug. 

“It’s a very competitive space,” said Mark Rutstein, Daiichi’s head of global oncology clinical development, in an interview at the conference. “Our scientists that built that innovative DXd platform, they are already far into working on next generation platforms.” 

An ADC from these new platforms was presented over the weekend at the conference, with early stage trials showing “promising” clinical activity in patients with advanced solid tumors that express a particular gene, Daiichi said in a statement. 

And Daiichi’s scientists are working on a platform that goes beyond the two the drugmaker has publicly disclosed, Rutstein said, though he would not disclose specifics. 

ADCs have three components: an antibody, a linker and a payload. The latter is the toxic part that kills the tumor cells, while the antibody is what ensures that the payload gets to the right cell.

Rutstein said a potential area of interest for Daiichi was technology that would target more than one antigen on a tumor at a time, as well as potentially having more than one toxic payload, though he wouldn’t say which option was being pursued. 

Meanwhile, Daiichi’s early stage ADC drug that’s showed promising results is not being developed in partnership with another pharma company. 

But Keller said that if the drug target has the potential to have dozens of indications, Daiichi would need to assess whether it could execute the trials and get the drug to patients in a reasonably fast time without a partner.