Zai Lab to Present New Data on Three Internally Developed Oncology Candidates at AACR 2026, Including Zocilurtatug Pelitecan, a DLL3-Targeting Antibody-Drug Conjugate (ADC)

Key Terms

antibody-drug conjugate medical

An antibody-drug conjugate is a targeted medicine that combines an antibody, which can identify specific cells, with a powerful drug designed to destroy those cells. This approach allows for precise treatment, minimizing damage to healthy tissue. For investors, developments in this area can signal advances in cancer therapies and potential growth opportunities in the biotech sector.

adc medical

An antibody-drug conjugate (ADC) is a targeted cancer medicine that pairs an antibody that recognizes specific markers on tumor cells with a potent cell-killing drug, connected so the toxic payload is delivered directly to the cancer. For investors, ADCs matter because successful ADCs can improve patient outcomes and reduce side effects compared with traditional chemotherapy, shaping clinical trial success, regulatory approval chances, commercial demand, and a company’s valuation much like a guided missile versus a general bomb.

dll3 medical

DLL3 is a protein found on the surface of some cells that helps control how cells communicate and develop; in certain cancers it becomes much more common on tumor cells than on healthy tissue. Investors watch DLL3 because it can serve as a visible target or marker for drugs and diagnostics—like a unique flag on bad cells—so therapies or tests that successfully exploit DLL3 can drive clinical progress, licensing deals, and potential future revenue.

lrrc15 medical

LRRC15 is a protein that sits on the surface of certain cells and can act as a marker or entry point for therapies and diagnostics. Investors care because drugs, antibodies, or imaging agents designed to bind LRRC15 can help target diseased tissue more precisely—like putting a homing beacon on a tumor—potentially improving treatment effectiveness and creating commercial opportunities if those products succeed in development and regulatory review.

pd-1 medical

PD-1 is a protein found on certain immune cells that acts like a brake, signaling the immune system to slow down and avoid damaging healthy tissue. Drugs that block PD-1 release that brake so immune cells can better attack cancer cells; because such therapies can produce large clinical benefits, regulatory approvals, trial outcomes, pricing and market uptake for PD-1 drugs can materially affect a drugmaker’s prospects and investor returns.

interleukin-12 medical

Interleukin-12 is a naturally occurring protein that acts as a messenger to activate and direct immune cells, helping the body fight infections and cancer. Investors pay attention because drugs that boost, mimic or block this messenger can become important therapies or cause safety and regulatory setbacks; positive or negative clinical trial and approval news about IL-12 pathways can materially affect a biotech company's value, like a signal that changes traffic flow in a busy market.

immunocytokine medical

An immunocytokine is a lab-designed medicine that fuses a targeting antibody with an immune signaling protein so the immune response is directed to specific cells or tissue. Think of it as a guided package that brings a signal to rally the body's defenses where needed; investors pay attention because this targeted approach can improve effectiveness, reduce side effects, and strongly influence clinical results, approvals, and commercial value.

phase 1 trial medical

Phase 1 trial is the first stage of testing a new drug or treatment in humans, focused mainly on safety, tolerability and finding the right dose, usually in a small group of volunteers or patients. For investors it matters because clear safety and dosing results reduce development risk, unlock later, larger trials, and can meaningfully change a biotech’s value and timeline — like a prototype’s maiden test flight that shows whether further investment makes sense.

- Zoci data show intracranial response in small-cell lung cancer (SCLC) with brain metastases, as well as activity in other neuroendocrine carcinomas

- ZL-6201 will be highlighted in a poster presentation showcasing its potential as an innovative ADC for the treatment of sarcoma and other LRRC15-positive solid tumors

- ZL-1222, a PD-1/IL-12, will also be featured in a poster presentation highlighting its potential as a next-generation immunocytokine therapy for the treatment of solid tumors

SHANGHAI & CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) today announced three of the Company’s internally-developed investigational oncology therapies will be presented across four poster sessions at the upcoming American Association for Cancer Research (AACR) Annual Meeting 2026 taking place April 17-22 in San Diego, California. These next-generation candidates include: zocilurtatug pelitecan (zoci, formerly ZL-1310), a DLL3-targeting antibody-drug conjugate (ADC) for small cell lung cancer (SCLC); ZL-6201, a leucine-rich repeat-containing protein 15 (LRRC15) ADC for the treatment of sarcoma and epithelial tumors with LRRC15 expressing cancer-associated fibroblasts (CAFs); and, ZL-1222, a PD-1 and interleukin-12 (IL-12) signaling attenuated mutein agonist immunocytokine for cancer immunotherapy.

“The breadth and profile of our global oncology pipeline, highlighted by zoci, ZL-6201, and ZL-1222, underscore our commitment to developing innovative therapies for cancers that remain difficult to treat with current standards of care,” said Rafael G. Amado, M.D., President, Head of Global Research and Development at Zai Lab. “Leveraging our integrated U.S.-China development model, we are advancing these programs with speed and quality, and the data we will present at AACR reinforces our confidence in these compounds.”

Zoci targets DLL3, a validated therapeutic target for SCLC that is overexpressed in many neuroendocrine tumors and is generally associated with poor clinical outcomes. Zoci is on track to become Zai Lab’s first global oncology launch, with plans for three registration-enabling studies across 2L+ SCLC, 1L SCLC, and extrapulmonary NECs by the end of 2026. Its potential best-in-class safety profile, coupled with compelling systemic and intracranial efficacy, supports its potential role as a new standard of care in previously treated ES-SCLC, as well as a backbone ADC in first line combination regimens, including those that reduce the burdens of chemotherapy. Studies with other combinations and lines of therapies are planned.

LRRC15 is a type I transmembrane protein and an appealing target for cancer therapy because it is overexpressed in various mesenchymal tumors, such as sarcoma, glioblastoma and melanoma, as well as in CAFs across many other tumor types. Zai Lab is evaluating ZL-6201 as a potential first-in-class LRRC15-targeting ADC for the treatment of multiple solid tumors.

Interleukin-12 treatments have shown potential therapeutic benefit across a range of cancer types; however, narrow therapeutic windows and toxicity concerns have limited the utility of this therapeutic class. Zai Lab is evaluating ZL-1222 as a potential next-generation PD-1 and attenuated IL-12 immunocytokine bispecific protein for cancer immunotherapy across multiple indications, potentially combining potent antitumor activity with improved systemic safety.

Details regarding the Zai Lab poster presentations at AACR 2026 are as follows:

Title: Discovery of ZL-6201, a novel LRRC15-targeting antibody drug conjugate (ADC) for the treatment of sarcomas and epithelial solid tumors
Session Title: Antibodies, Antibody-Drug Conjugates, and Nucleic Acids
Date/Time: Monday, April 20, 2026, from 9:00 a.m. - 12:00 p.m. PT
Location: San Diego Convention Center, Poster Section 38
Poster Board Number: 7
Publish Abstract Number: 2399

Title: ZL-1222, a PD-1-targeted potency-reduced IL-12 immunocytokine, overcomes PD-1 resistance and enhances antitumor immunity with an accepted safety profile
Session Title: Monoclonal Antibodies and Antibody-Cytokine Platforms
Date/Time: Tuesday, April 21, 2026, from 9:00 a.m. - 12:00 p.m. PT
Location: San Diego Convention Center, Poster Section 9
Poster Board Number: 2
Publish Abstract Number: 4331

Title: Intracranial activity of ZL-1310, a DLL3-targeted ADC, in patients with previously treated extensive-stage small cell lung cancer and baseline brain metastasis: Analysis of a phase 1 trial
Session Title: Phase 1 Clinical Trials
Date/Time: Tuesday, April 21, 2026, from 9:00 a.m. - 12:00 p.m. PT
Location: San Diego Convention Center, Poster Section 50
Poster Board Number: 15
Publish Abstract Number: CT193

Title: Preliminary results from the phase 1b/2, open-label, multi-center study of ZL-1310, a DLL3-targeted ADC, in patients with neuroendocrine carcinomas and other selected solid tumors
Session Title: Phase 1 Clinical Trials
Date/Time: Tuesday, April 21, 2026, from 9:00 a.m. - 12:00 p.m. PT
Location: San Diego Convention Center, Poster Section 50
Poster Board Number: 11
Publish Abstract Number: CT189

About Zai Lab

Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) is an innovative, research-based, commercial-stage biopharmaceutical company based in China and the United States. We are focused on discovering, developing, and commercializing innovative products that address medical conditions with significant unmet needs in the areas of oncology, immunology, neuroscience, and infectious disease. Our goal is to leverage our competencies and resources to positively impact human health.

For additional information about Zai Lab, please visit www.zailaboratory.com or follow us at https://x.com/ZaiLab_Global.

Zai Lab Forward-Looking Statements

This press release contains forward-looking statements relating to our future expectations, plans, and prospects, for Zai Lab, including, without limitation, statements relating to our prospects and plans for developing and commercializing zocilurtatug pelitecan (ZL-1310), ZL-6201 and ZL-1222, the potential benefits of zocilurtatug pelitecan (ZL-1310), ZL-6201 and ZL-1222, and the potential treatment of small cell lung cancer, neuroendocrine carcinomas, and solid tumors. All statements, other than statements of historical fact, included in this press release are forward-looking statements, and can be identified by words such as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “plan,” “possible,” “potential,” “will,” “would,” and other similar expressions. Such statements constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are not guarantees or assurances of future performance. Forward-looking statements are based on our expectations and assumptions as of the date of this press release and are subject to inherent uncertainties, risks and changes in circumstances that may differ materially from those contemplated by the forward-looking statements. We may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in our forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results may differ materially from those indicated by forward-looking statements as a result of various important factors, including but not limited to (1) our ability to successfully commercialize and generate revenue from our approved products, (2) our ability to obtain funding for our operations and business initiatives, (3) the results of our clinical and pre-clinical development of our product candidates, (4) the content and timing of decisions made by the relevant regulatory authorities regarding regulatory approvals of our product candidates, (5) risks related to doing business in China, and (6) other factors identified in our most recent annual and quarterly reports and in other reports we have filed with the U.S. Securities and Exchange Commission (SEC). We anticipate that subsequent events and developments will cause our expectations and assumptions to change, and we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as may be required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

Our SEC filings can be found on our website at www.zailaboratory.com and on the SEC’s website at www.SEC.gov.

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For more information, please contact:

Investor Relations:

Christine Chiou / Cyan Liu

+1 (917) 886-6929 / +86 195 3130 8895

christine.chiou1@zailaboratory.com / cyan.liu@zailaboratory.com

Media:

Shaun Maccoun / Xiaoyu Chen

+1 (857) 270-8854 / +86 185 0015 5011

shaun.maccoun@zailaboratory.com / xiaoyu.chen@zailaboratory.com

Source: Zai Lab Limited