Novartis to buy Myricx Bio for up to $1.5 billion in ADC push

Novartis is paying $1.1 billion upfront for a UK biotech whose novel ADC payload platform could overcome the resistance and toxicity limits of existing cancer therapies.

Novartis agreed to acquire Myricx Bio for as much as $1.5 billion, betting that a novel class of antibody-drug conjugate payloads can overcome the resistance and toxicity limits that constrain existing cancer treatments.

"There is a widely recognised and critical unmet need for new ADC payloads that can improve the standard of care over current payloads, overcome payload resistance, improve tolerability and offer a wider therapeutic index," Mohit Rawat, chief executive officer of Myricx Bio, said.

The deal includes $1.1 billion in cash at closing plus potential milestone payments, the companies said Monday. Myricx Bio, spun out of Imperial College London and the Francis Crick Institute in 2019, raised 90 million pounds ($114 million) in a Series A round in mid-2024 led by Novo Holdings and Abingworth. Its two lead ADC candidates target B7-H3 and HER2, established solid-tumor antigens expressed across multiple cancer types including lung, breast, and prostate.

Retreatment with ADCs using the same payload class reduces objective response rates by more than 50 percent, and more than half of leading ADC regimens require dose reductions or interruptions due to toxicity, according to Myricx Bio. The company's NMTi payloads use a completely different mechanism — inhibiting an enzyme critical to multiple cancer-cell survival pathways — that could expand the therapeutic index and treat tumors that have become resistant to current ADCs. The transaction is expected to close in the second half of 2026, subject to regulatory approvals.

N-myristoyltransferase, or NMT, is an enzyme that adds a specific lipid to multiple proteins essential for cancer cell survival. Myricx Bio's payloads inhibit this enzyme, driving complete tumor regression in preclinical models across multiple solid-tumor types, the company said. Unlike topoisomerase-1 inhibitors and tubulin inhibitors — the payload classes used in most approved ADCs, including Pfizer's Mylotarg and Daiichi Sankyo's Enhertu — NMT inhibitors have a differentiated toxicity profile, potentially allowing higher and more durable dosing.

"ADCs have become an important part of cancer treatment, but there remains a clear need for new payload mechanisms to overcome resistance and expand their impact for patients," Fiona Marshall, president of biomedical research at Novartis, said. "Myricx Bio has developed a promising NMTi payload platform with a differentiated mechanism that could broaden the use of ADCs across multiple tumor settings."

The platform's broad applicability across antigens — Myricx Bio has demonstrated preclinical efficacy against multiple targets beyond B7-H3 and HER2 — gives Novartis a potential pipeline-in-a-platform asset. The Swiss drugmaker already has a significant ADC presence through its own pipeline and partnerships, including a licensing deal with Daiichi Sankyo for three ADCs signed in 2024.

Sofinnova Partners and Brandon Capital co-led Myricx Bio's seed round in 2019, backing the founders' hypothesis that NMT inhibition could unlock a new ADC payload class. The company later pivoted from small-molecule development to an ADC platform — a strategic shift that Sofinnova helped shape, according to Maina Bhaman, a partner at the firm.

"I first met Roberto and Ed at Imperial, long before any of this existed," Bhaman said, referring to founders Roberto Solari and Professor Ed Tate. "The team at Myricx Bio has executed with exceptional discipline and ambition ever since, evolving the company from a seed hypothesis to a Novartis acquisition."

The Series A in 2024 added Eli Lilly, Cancer Research Horizons, and the British Business Bank as investors, giving the company enough capital to advance two lead assets into preclinical development. Mohit Rawat joined as CEO in 2025 to steer the company through its next stage of growth, leading to this deal.

For Novartis, the acquisition adds a platform technology that could be applied across its broader oncology pipeline, mirroring the strategy it used to scale radioligand therapies into a multibillion-dollar franchise. The Swiss drugmaker did not disclose whether it plans to advance Myricx Bio's B7-H3 and HER2 programs into clinical trials or expand the NMTi platform to additional targets.

The acquisition is the seventh exit in three years for Sofinnova Partners, underscoring the venture firm's ability to generate returns from early-stage European life sciences investments. For Eli Lilly, which participated in the Series A, the deal provides a near-term return on its 2024 investment. The broader ADC market, valued at more than $10 billion in annual sales, is expected to grow as new payload mechanisms enter the clinic and overcome the limitations of first-generation therapies.

This article is for informational purposes only and does not constitute investment advice.