Myricx Bio raises $114 million for ADCs with novel payload

The UK start-up Myricx Bio began with a focus on small-molecule inhibitors. Incorporating those inhibitors into antibody-drug conjugates (ADCs) has now netted it a substantial cash runway. Life sciences investors led by Novo Holdings and Abingworth have handed Myricx £90 million ($114 million) in series A funding—the largest series A for a UK-based biotechnology firm this year.

It’s a huge vote of confidence in Myricx’s approach, CEO Robin Carr says, especially when biotechs in the UK and Europe are often at a funding disadvantage to their counterparts across the Atlantic.

Investors have recently shown a lot of interest in ADCs via big-ticket acquisitions and partnerships. In Syneos Health’s Dealmakers’ Intentions Survey 2024, the modality was listed number 1 on investors’ radar.

But Carr contends that what makes Myricx different is its deep understanding of a specific enzyme not targeted by existing ADCs: N-myristoyltransferase (NMT).

NMT is involved in protein lipidation, sticking myristic acid onto the N-terminal domain of proteins. And it’s a pretty ubiquitous modification. In total, around 150 proteins in the human body are modified in this way.

Chemists Ed Tate, of Imperial College London and the Francis Crick Institute, and Andy Bell, who worked with Tate between his roles at Pfizer and Exscientia, have years of experience building inhibitors of NMT. But it was biologist Roberto Solari, then a visiting professor at Imperial College, who saw the potential to create a company that uses NMT inhibition to treat cancer, because of NMT’s importance in multiple cellular processes in cancer cells.

The trio launched Myricx in 2019. Carr joined from the big drug company GSK, originally as chief development officer, because he thought the possibilities were “unbelievably cool.”

Since launching, the firm has enlisted key opinion leaders to help it go from promising start to a molecule in the clinic. With their counsel, the Myricx team decided to focus on the ADC option—linking NMT-inhibiting small molecules to antibodies to increase their specificity and selectivity.

ADCs might be a hot topic, but it was still risky to pivot to a new approach. Luckily, the timing was superb, Carr says. Approved ADC drugs are becoming less effective as cancers develop resistance, and clinicians are want new options. Myricx’s preclinical data show that its molecules have high efficacy in cancer models that are resistant to current ADC payloads.

The positive early data has allowed the company to recruit “very senior people,” Carr says. Good solid-tumor efficacy and tolerability data have also impressed investors. With the new influx of cash, Carr plans to grow the team to around 15 employees while continuing to use the adviser network that has served the company so well.

Myricx will be advancing two molecules with the aim of getting the first into the clinic by mid-2026. Carr says the money in the coffers should give it the resilience to get there.