维立志博-B自愿公告：LBL-024与LBL-034共六项研究摘要上线2026 ESMO官网，含1篇LBA与3项口头报告

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Nanjing Leads Biolabs Co., Ltd.
南京 維立志博生物科技股份有限公司
(A joint stock company established in the People’s Republic of China with limited liability)

(Stock Code: 9887)

VOLUNTARY ANNOUNCEMENT
ABSTRACTS OF SIX STUDIES PUBLISHED AT 2026 ESMO
This announcement is made by Nanjing Leads Biolabs Co., Ltd. (the “Company ”, together
with its subsidiaries, the “Group”) on a voluntary basis to inform shareholders and potential
investors of the Company about the latest business development of the Company.
The Company is pleased to announce that the full abstracts of six studies of its self-developed
LBL-024 (Opamtistomig, an anti-PD-L1/4-1BB bispecific antibody) and LBL-034 (GPRC5D/
CD3 bispecific T-Cell engager, TCE), covering clinical studies, translational research and
meta-analyses, have been published on the official website of 2026 Annual Meeting of the
European Society for Medical Oncology (“ 2026 ESMO”). The data collectively demonstrate
trends of durable responses and long-tail survival benefits with LBL-024 across multiple
immunologically “cold tumors,” supporting its potential as a pan-tumor therapy, and highlight
the differentiated capabilities of the Company ’s X-body and TCE technology platforms.
Notably, three studies of LBL-024 and LBL-034 have been selected for Proffered Paper
presentations at 2026 ESMO, including one study selected as a Late-Breaking Abstract
( “ LBA ” ). Detailed and updated data from these studies will be presented during the oral
presentations at the 2026 ESMO.

LBL-024 AS FIRST-LINE TREATMENT FOR EP-NEC (ABSTRACT NO. 5836)
As of April 3, 2026, the study had enrolled 69 patients with advanced extrapulmonary
neuroendocrine carcinoma (“EP-NEC”) who had not received prior systemic therapy. Sixtyfive patients were evaluable for efficacy, and the median follow-up for the overall population
was 16.9 months.
Across all dose levels, the median duration of response (“ mDoR”) was 10.2 months and the
median overall survival ( “ mOS ” ) had not yet matured. In the 6 mg/kg and 15 mg/kg dose
groups, the mDoR was 15.5 months and 10.2 months, respectively, and the 15-month overall
survival (“OS”) rates were 63.6% and 58.4%, respectively.

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Among patients with PD-L1-positive disease (combined positive score (“ CPS ” ) ≥1), the
15-month OS rate was 66.7% in each of the 6 mg/kg and 15 mg/kg dose groups. Among patients
with PD-L1-negative disease (CPS <1), the corresponding 15-month OS rates were 57.1% and
53.6%, respectively.
No dose-limiting toxicities ( “ DLTs ” ) were observed. Treatment-related adverse events
( “ TRAEs ” ) were primarily chemotherapy-induced myelosuppression, and no severe
hepatotoxicity was observed.
EP-NEC is a rapidly progressing disease with a poor prognosis, and historical data indicate
an mOS of approximately 12 months with first-line platinum-based chemotherapy. In this
study, the median follow-up was approaching 17 months while the mOS had not been reached,
suggesting that survival benefit continued to accrue and that the survival curve exhibited a
long-tail trend.

LBL-024 AS FIRST-LINE TREATMENT FOR BTC (ABSTRACT NO. 5649)
As of April 1, 2026, 20 patients with advanced biliary tract cancer (“BTC”) had been enrolled
in the safety lead-in phase. The median age was 61 years. The cohort included two patients
with gallbladder cancer, 13 with intrahepatic cholangiocarcinoma and five with extrahepatic
cholangiocarcinoma; 85.0% of patients had metastatic disease.
The overall objective response rate (“ORR”) was 55.0% and the disease control rate (“DCR”)
was 100.0%. Among patients with PD-L1-positive disease (CPS ≥1), the ORR was 100.0%.
TEAEs primarily comprised chemotherapy-related hematologic toxicities, including
leukopenia, neutropenia and anemia. No new safety signals were observed.
Patients with PD-L1-negative disease (CPS <1) accounted for 60% of the study population,
compared with generally less than 30% in comparable first-line BTC studies, while other
baseline characteristics were broadly comparable. Follow-up for the abstract data was limited,
and updated follow-up data are expected to be presented at 2026 ESMO.

TRANSLATIONAL STUDY OF LBL-024 IN MSS COLORECTAL CANCER
(ABSTRACT NO. 5512)
In a preclinical translational study of microsatellite-stable (“ MSS ”) colorectal cancer, LBL024 demonstrated dose-dependent tumor growth inhibition. Tumor growth inhibition by tumor
volume was 69.27%, 94.53% and 99.84% in the 2 mg/kg, 8 mg/kg and 30 mg/kg groups,
respectively. In the 30 mg/kg group, complete tumor regression was achieved in two of five
mice. At molar-equivalent doses, LBL-024 demonstrated greater antitumor activity than
pembrolizumab.

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The study further demonstrated that intratumoral soluble 4-1BB levels were several dozen
times higher than peripheral levels, consistent with the design of conditional activation within
the tumor. Tumor-infiltrating T cells increased in a dose-dependent manner: the proportion
of CD3+ cells increased from 30.84% in the control group to as high as 68.92%, while the
proportion of CD8+ cells increased from 56.05% to as high as 88.72%. The proportion
of immunosuppressive regulatory T cells decreased from 9.58% to as low as 1.71%, and
intratumoral cytokines, including TNF-α and IFN-γ, increased in a dose-dependent manner.
These findings indicate that LBL-024 induces intratumoral immune activation and reshapes
the tumor microenvironment by conditionally activating local CD8+ T cells and reducing
immunosuppressive regulatory T cells. The mechanism is consistent with the efficacy signals
and safety profile observed in clinical studies of LBL-024 and supports further clinical
development in MSS colorectal cancer and other immunotherapy-resistant solid tumors.

LBL-034 FOR RELAPSED OR REFRACTORY MULTIPLE MYELOMA
(ABSTRACT NO. 4727)
As of March 31, 2026, 56 heavily pretreated patients with relapsed or refractory multiple
myeloma (“RRMM”) had been enrolled. The median number of prior lines of therapy was five.
Of the patients enrolled, 73.2% were triple-class exposed, 57.1% were penta-drug exposed,
28.6% had previously undergone autologous stem cell transplantation, 16.1% had previously
received BCMA CAR-T therapy and 23.2% had extramedullary disease (“EMD”).
Among 55 efficacy-evaluable patients, the median follow-up was 16.0 months, the median
progression-free survival (“ mPFS”) was 15.8 months and the mDoR had not been reached.
At doses of 400–1,200 μg/kg, the 18-month progression-free survival (“PFS”) rate was 58.0%.
Among 23 patients who achieved a complete response or better, the 18-month PFS rate was
87.7%, the median time to complete response or better was 3.94 months and the minimal
residual disease-negative rate at a sensitivity of 10^-5 was 72.7%.
Among high-risk patients with EMD, the ORR was 75.0%, the median time to response was
3.07 months, the mPFS was 11.5 months and the 18-month PFS rate was 46.9%.
LBL-034 demonstrated a favorable safety profile. There was only one event of Grade 3 or
higher cytokine release syndrome (“CRS”), and no treatment-related deaths occurred.
The results demonstrate deep and durable responses in heavily pretreated and high-risk patients
with RRMM while maintaining a low incidence of severe CRS, supporting the effectiveness and
safety of the conditional T-cell redirection and activation mechanism of the Company’s TCE
technology platform.

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ABOUT LBL-024 (OPAMTISTOMIG)
LBL-024 is a bispecific antibody simultaneously targeting PD-L1 and 4-1BB, with the potential
to become a pan-tumor IO 2.0 cornerstone therapy that offers survival benefits. To date, LBL
024 has been evaluated in clinical studies for 14 indications, including one pivotal single arm
registrational clinical study, one confirmatory Phase III clinical study and nine proof-of concept
studies, covering multiple major cancer types and “cold tumors. ” Among the seven tumor
types in which LBL-024 has been clinically validated, LBL-024 has demonstrated outstanding
clinical value and broad therapeutic prospects, including extrapulmonary neuroendocrine
carcinoma (EP-NEC), non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC),
biliary tract cancer (BTC), hepatocellular carcinoma (HCC), esophageal squamous cell
carcinoma (ESCC) and ovarian cancer (OC).
Leveraging our self-developed X-body™ platform with full intellectual property rights, LBL
024 achieves conditional activation of 4-1BB, relieving PD-1/PD-L1 immunosuppression while
enhancing 4-1BB-regulated T-cell activation, achieving a synergistic effect in eliminating
tumors. LBL-024 demonstrates a safety profile comparable to PD-1/PD-L1 inhibitors and
greater potential for broad-spectrum cancer treatment. In particular, activation of 4-1BB can
reactivate exhausted T cells and substantially promote their proliferation, making 4-1BB
targeted therapies potentially suitable for the treatment of immunologically “cold tumors” that
are resistant or unresponsive to PD-1/PD-L1 inhibitors, and may bring long-lasting survival
benefits.
In October 2024, LBL-024 was granted Breakthrough Therapy Designation by the NMPA,
and in November 2024, it received Orphan Drug Designation from the U.S. Food and Drug
Administration (the “FDA”). In January 2026, LBL-024 was granted Fast Track Designation
by the FDA and Orphan Drug Designation in the European Union. In September 2026, LBL024 was granted Orphan Drug Designation by Japan’s Ministry of Health, Labour and Welfare
(“MHLW”). In October 2026, it received Fast Track Designation from the FDA for the firstline treatment of advanced BTC.
In July 2026, the Marketing Authorization Application of LBL-024 as an innovative biological
product was included in the NMPA’s priority review and approval procedure and was formally
accepted in August 2026. LBL-024 is expected to become the world ’s first approved 4-1BB
antibody drug, the world’s first approved agonistic antibody drug and the world ’s first approved
therapy targeting EP-NEC.

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ABOUT LBL-034
LBL-034 is a humanized bispecific T-cell engager (TCE) targeting GPRC5D and CD3,
developed using the Company ’s proprietary LeadsBody™ platform. LBL-034 employs a 2:1
structural design comprising two high-affinity Fab domains targeting GPRC5D and one singlechain variable fragment targeting CD3. It is designed to selectively target GPRC5D-positive
tumor cells and conditionally activate T cells, thereby reducing the risks of cytokine release,
systemic toxicity and T-cell exhaustion while enabling potent, sustained antitumor activity.
LBL-034 has demonstrated encouraging efficacy signals in preclinical and clinical studies.
Breakthrough clinical data for LBL-034 monotherapy in RRMM were presented in the opening
oral presentation at the 2025 American Society of Hematology Annual Meeting, and further
updated clinical data have been selected for a Proffered Paper presentation at 2026 ESMO.
LBL-034 received Orphan Drug Designation from the FDA in October 2024 and Fast Track
Designation from the FDA in January 2026. A Phase III clinical study of LBL-034 is currently
in preparation.
Cautionary Statement required by Rule 18A.05 of the Rules Governing the Listing of
Securities on The Stock Exchange of Hong Kong Limited: The Company cannot guarantee
that it will be able to develop, or ultimately market, LBL-024 and LBL-034, successfully.
Shareholders and potential investors of the Company are advised to exercise due care when
dealing in the shares of the Company.
By order of the Board
Nanjing Leads Biolabs Co., Ltd.
南京維立志博生物科技股份有限公司
Dr. KANG XIAOQIANG
Chairman, Executive Director and
Chief Executive Officer
Nanjing, PRC, October 19, 2026
As at the date of this announcement, the board of directors of the Company comprises: (i)
Dr. Kang Xiaoqiang (Chairman of the Board), Dr. Lai Shoupeng and Mr. Zuo Honggang
as executive Directors; (ii) Mr. Zhang Yincheng, Dr. Chen Renhai and Dr. Wu Fenglan as
non-executive Directors; and (iii) Dr. Zhang Hongbing, Mr. Du Yilong and Ms. Du Jiliu as
independent non-executive Directors.

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