[Min Ji-Son, Edaily Reporter] On Oct. 16, South Korean pharmaceutical and biotech stocks rallied, buoyed by overnight gains in U.S. healthcare shares and a broader rebound in domestic equities. Samsung Epis Holdings and Samyang Biopharm advanced on the KOSPI, while LivsMed, HansBiomed, L&C Bio, and LigaChem Biosciences posted strong gains on the KOSDAQ.

The rally was largely driven by improving sector-wide sentiment rather than company-specific catalysts. The KOSDAQ surged enough to trigger a buy-side trading curb—known locally as a “buy sidecar”—temporarily suspending program buy orders as the broader market rebounded sharply.

Industry observers noted that much of the day’s gains reflected a recovery from recent losses, with relatively few stocks supported by new clinical data, earnings announcements, or other significant developments.

“Capital had been heavily concentrated in semiconductor stocks, leaving South Korean pharmaceutical and biotech shares under significant selling pressure,” said one biotech industry official. “The recent reversal of that trend appears to have triggered a rebound, but the sector still has a long way to go before fully recovering.”

LigaChem Bio Rises as CLDN18.2 ADC Enters Clinical Trials

Among the day’s gainers, LigaChem Biosciences stood out due to a company-specific development.

According to KG Zeroin’s MP Doctor platform, LigaChem Bio closed at 68,200 won on the KOSDAQ, up 8.60%, or 5,400 won, from the previous session. The stock briefly traded above 70,000 won during the trading day.

The gains followed news that the company had dosed the first patient in a global Phase 1/2 trial of LCB02A, its internally developed antibody-drug conjugate (ADC) targeting claudin 18.2, or CLDN18.2.

The U.S. Food and Drug Administration (FDA) approved the Investigational New Drug (IND) application for LCB02A in May. The first patient received the drug on October 15 at a clinical trial site in North America.

The study will enroll up to 191 patients with CLDN18.2-positive advanced solid tumors whose disease has progressed despite prior treatment.

The Phase 1 portion will evaluate safety and tolerability while determining an appropriate dose. The subsequent Phase 2 dose-expansion stage will assess antitumor activity in patients with CLDN18.2-expressing cancers, including gastric, gastroesophageal junction, and pancreatic cancers.

CLDN18.2 is a protein expressed in certain solid tumors, particularly gastric and pancreatic cancers. Its expression on tumor cells makes it an attractive target for therapies designed to selectively deliver anticancer drugs to malignant tissue.

Astellas Pharma’s Vyloy (zolbetuximab) is already approved as a CLDN18.2-targeted treatment, but it is a monoclonal antibody rather than an ADC.

No CLDN18.2-targeted ADC has yet received regulatory approval anywhere in the world.

For LigaChem Bio, the opportunity lies in establishing a competitive position in an emerging treatment market by demonstrating both efficacy and safety in clinical trials.

A different payload could give LigaChem Bio a competitive edge

One of the key features LigaChem Bio is emphasizing is LCB02A’s payload—the cytotoxic drug component carried by an ADC.

ADCs combine an antibody that recognizes a target on cancer cells with a potent anticancer agent, enabling the drug to be delivered to tumor cells.

LCB02A uses LigaChem Bio’s proprietary ConjuAll ADC platform to attach exatecan, a topoisomerase I (Topo1) inhibitor, to an antibody targeting CLDN18.2.

The company said it has developed a uniform structure with a drug-to-antibody ratio of four, using a linker designed to remain highly stable in the bloodstream.

“Candidates from Chinese and global developers that are further along in clinical development use different classes of payloads,” a LigaChem Bio official said. “Based on preclinical studies, we believe LCB02A has the potential to demonstrate competitive efficacy and safety compared to the ADCs evaluated.”

LigaChem Bio believes that its distinct payload could provide an opportunity to enter the market even if rival CLDN18.2 ADCs reach commercialization first.

The company is considering not only direct competition with earlier entrants but also the possibility of treating patients who develop resistance to existing therapies or require alternative treatment options.

"We considered both the market in which LCB02A would compete directly with more advanced candidates and the potential to offer a different payload-based treatment option to patients who develop resistance after receiving those therapies," the official said.

This strategy reflects an effort to differentiate LCB02A through its drug payload rather than relying solely on the same tumor target as competing ADC programs.

Whether that approach translates into a clinical advantage will depend on human efficacy and safety data, including how LCB02A performs in patients previously exposed to other CLDN18.2-targeted treatments.

LigaChem Bio plans to present two posters at the European Society for Medical Oncology (ESMO) Congress 2026, scheduled for October 23–27 in Madrid, Spain.

The presentations will cover preclinical findings for LCB02A and the design of its global clinical trial, providing further details on the development rationale behind the combination of the ConjuAll platform and the exatecan payload.

Initial clinical findings could begin to emerge in the second half of next year.

“It is difficult to specify an exact data release date because we have only just started dosing the first patient,” said a LigaChem Bio official. “However, we expect initial results to begin emerging in the second half of 2027, with a clearer picture available by the first half of 2028 at the latest.”

The company is also keeping both independent development and potential global licensing options open.

Whether LigaChem Bio advances LCB02A into late-stage clinical development on its own or partners with a multinational pharmaceutical company will depend on the clinical data and the terms of any potential agreement.

"If an attractive partnership opportunity arises, we could pursue a licensing deal," the official said. "For now, we are preparing for both independent clinical development and potential licensing opportunities."