Antibody-drug conjugate (ADC) specialist Aimedbio Inc. announced Oct. 16 the signing of a potential $991 million deal with Boehringer Ingelheim GmbH to license out its novel preclinical ADC asset targeting solid tumors, including KRAS mutations, which is set to enter phase I study next year.

Specific financial terms, including those on milestone payments, were not disclosed. The $991 million was inclusive of an up-front payment, development, regulatory and commercial milestones, along with separate royalty payments on net sales.

The near $1 billion deal sheet is expected to be a boost for the privately held, Seoul, South Korea-based biotech, which has been preparing for a Kosdaq listing by the end of 2025.

Aimedbio noted that the company is currently expanding collaborations with numerous global companies, having filed a securities report to the Korea Exchange (KRX) on Sept. 29, 2025, to float a stock sale within the year.

Adds mystery candidate to Boehringer’s ADC portfolio

Ingelheim, Germany-based Boehringer announced first the signing of the global collaboration and license deal after market close on Oct. 15.

Details on the licensed asset were also scant; however, Aimedbio noted that the candidate features a topoisomerase 1 (TOPO1) inhibitor payload and targets solid tumors, including KRAS mutations. The description aligned with Boehringer’s, which detailed that the candidate’s cytotoxic agent is a derivative of exatecan, and that the asset targets a protein that is highly expressed across a broad spectrum of cancers, minimally present in normal tissues and plays a significant role in tumor growth, metastasis and therapy resistance.

Targeting the protein with an ADC is expected to enable highly specific cytotoxic action against the tumor cells, enhancing efficacy and supporting better outcomes for patients, according to Boehringer.

“ADCs are a powerful therapeutic approach that combines biological precision with chemical potency,” said Vittoria Zinzalla, global head of experimental medicine at Boehringer. “Targeting the specific cancer surface marker with Aimedbio’s ADC may expand precision medicine treatment options for currently hard-to-treat cancers.”

For Boehringer, the agreement further strengthens its growing ADC portfolio, driven by Basel, Switzerland-based subsidiary, NBE Therapeutics AG, which it bought for about $1.4 billion in December 2020.

NBE/Boehringer’s NBE-002 is a ROR1 ADC conjugated to PNU-159682 that moved into phase II study for solid tumors, including triple-negative breast, lung and ovarian cancers, as of February.

Also in the cancer space, Boehringer most recently won accelerated approval from the U.S. FDA for Hernexeos (zongertinib), making it the first oral HER2-targeted therapy for patients with advanced non-small-cell lung cancer (NSCLC).

‘Yet another’ spotlight on Aimedbio’s ADC

Meanwhile, the mystery licensed ADC candidate is slated to enter first-in-human phase I study in 2026, according to Aimedbio.

“We believe this program has the potential to transform the treatment landscape for many cancers that currently lack effective options,” Aimedbio’s chief technology officer, Nam Do-hyun, said. "This agreement is significant as it demonstrates yet another global recognition of the potential of Aimedbio's precision antibody-based ADC asset.”

As reported by BioWorld, Aimedbio, a spinoff of Seoul-based Samsung Medical Center (SMC), raised ₩51.1 billion (US$37.15 million) in pre-IPO funding in June to advance its portfolio of ADC candidates, raising the company’s total funding to ₩113.5 billion.

Nam founded Aimedbio in August 2018. He is also currently a neurosurgeon at SMC, known as one of the “big 5” hospitals in South Korea. Her Nam-gu, Aimedbio’s former R&D head, serves as company CEO.

At the time of the pre-IPO round, a company official confirmed to BioWorld that Aimedbio would focus on the preclinical development of AMB-303 and AMB-304, while expanding significantly into a next-generation ADC platform and potentially signing more license deals.

Both AMB-303 and AMB-304 were listed as preclinical solid-tumor-targeting ADC candidates on the company’s website as of June 2025.

The other three out of five candidates in Aimedbio’s pipeline – AMB-302, AMB-001 (atopic dermatitis and dementia) and AMB-018 (solid tumors) – are supported via grants from the government’s Korea Drug Development Fund (KDDF).

In December 2024, the company out-licensed AMB-302 to New Haven, Conn.-based Biohaven Ltd. Aimedbio also agreed to co-investigate AMB-302 with Genequantum Healthcare (Suzhou) Co. Ltd.

Aimedbio caught the eye of the Samsung group in 2023, with the Samsung Life Science Fund making its fourth equity investment into the company under undisclosed terms. With the investment, Aimedbio agreed to conduct joint research with Incheon-based Samsung Biologics Co. Ltd. to create an “ADC toolbox” and collaborate across multiple areas.

Aimedbio said its integrated ADC development technology rests on its multi-omics platform and proprietary patient-derived cell (PDC) and patient-derived xenograft (PDX) model-based antibody panning ADC platforms.

Meanwhile, there has been no signs of cooling demand for ADCs in the industry. Just a day prior, Munich-based ADC maker Tubulis GmbH smashed the European record of series C financings with a hefty €308 million (US$356 million) round to expand clinical development of TUB-040 and its ADC portfolio.