- CEO Tony Xue
- Total raised $120 million
- Headquarters Suzhou, China
In the ADC renaissance of the last few years, Japan’s venerable pharma company Daiichi Sankyo has won many of the headlines.
But if MediLink Therapeutics has its way, Chinese biotechs will cement the treatments’ dominance in oncology — and prove that China’s new generation of drugmakers can truly compete on the global stage.
MediLink has raised $120 million in funding and counts BioNTech and Roche as partners. The Suzhou-based company is at the forefront of a dealmaking wave in which multinational pharma companies have increasingly looked to China as a source of early drug candidates.
And MediLink’s licensing deals with multinational pharmas are a bright spot amid growing US-China tensions that have cast a chill over much of the local industry’s work with US companies.
The biotech, founded in 2020, came on the scene just as “nearly every pharma was looking for ADCs” again after the drugs had fallen out of favor a decade prior, said Jiaqiang Cai, MediLink’s co-founder and chief scientific officer.
That wasn’t always the case. Cai previously worked at Sichuan Kelun-Biotech, which began pursuing ADCs in 2013 after the FDA approval of Roche’s Kadcyla sparked an ADC me-too frenzy in China. While he believed Kelun had a me-better molecule, at 2019’s JP Morgan conference in San Francisco, everyone turned him down for meetings to talk about licensing deals. They saw no future in ADCs, and “nobody believed everything we did in China at that time,” he said.
A few months later, Merck came calling after AstraZeneca’s up to $7 billion ADC deal with Daiichi Sankyo stunned the industry. Merck licensed Kelun’s TROP2 ADC and eventually inked two more deals for other programs, each with billions of dollars in potential milestones.
By then, Cai had left to work for another domestic pharma company in Shanghai. But Tony Xue, his former ADC partner at Kelun, wondered if they could repeat the success with a new startup and a new platform.
“Kelun’s technology is actually very good for TROP2. But for many other targets, [it’s] probably too unstable, and also [the] potency is too high,” Cai said.
That fine balance of delivering enough chemotherapy to kill cancer without poisoning the rest of the body has long been the key challenge for ADCs. MediLink works with a version of the standard antibody-linker-payload combo that is stable in healthy tissue and doesn’t require internalization of the antibody — meaning its cancer-killing drugs can be unleashed outside the cell, removing some barriers to efficacy.
The concept isn’t new. But the way MediLink turned it into reality is emblematic of the fast, iterative engineering that’s helped many Chinese startups get ahead in the drug discovery race. The tiny team led by Xue, Cai and COO Joey Xiao came up with six different ideas of how to structure the payload-linker complex, then hired a CRO to test them all in parallel.
They got to work in December 2020. Three months later, in February 2021, they had a molecule that met their criteria. And in June of that year, optimization was complete.
“During six months, they made 200 molecules for us. And only six chemists,” he said.
Roche made MediLink the first partner for its Shanghai R&D group, and sees the startup “as a fast-growing China biotech with R&D expertise and proprietary ADC platform technology, including differentiated TOP1 inhibitor payload and linker,” a spokesperson for the Swiss drugmaker said.
There can be downsides to speed: MediLink and BioNTech’s HER3 ADC was placed on a clinical hold by regulators earlier this year after patient deaths were deemed related to treatment. The serious toxicity arose as MediLink expanded the patient cohort in a short period of time.
“We moved too fast,” Cai told Endpoints. But he said the companies also reacted swiftly to pause enrollment and notify regulators. They ended up adjusting the dose, and the hold was lifted in August.
With money from the out-licensing deals, MediLink has been able to grow its team to almost 180 people, even though it hasn’t raised any new venture funding since closing a $70 million Series B in 2022.
With many of MediLink’s assets already claimed by a partner (before BioNTech and Roche, it also struck deals with Zai Lab, Harbour BioMed and Henlius) the company’s leaders are hoping to keep some candidates in-house before considering more deals, which Cai said would likely happen at a later phase.
“For anything you try to license out, you need to get the idea earlier than others, and then you have something other people don’t have,” he said.
When asked about concerns that promising data from Chinese patients wouldn’t translate in trials outside the country, Cai noted that the much higher body weight for US patients could skew the pharmacokinetics, and different dose settings may be required in different countries.
“I believe eventually it will work,” he said.
Key investors: LYFE Capital, Qiming Venture Partners, Legend Capital, Loyal Valley Capital, Apricot Capital, C&D Emerging Capital, Highlight Capital
Find the full list of 2024 Endpoints 11 winners here.