OBI Pharma Announces Poster Presentations at the AACR 2025 Annual Meeting for OBI-992 and OBI-902 Antibody-Drug Conjugates (ADCs), GlycOBI® and ThiOBI® ADC enabling technologies, the OBI-3424 prodrug, and Globo H (GH) science

Poster Presentations featuring the latest advancements on anti-TROP2 ADCs (OBI 992 and OBI 902), AKR1C3 prodrug (OBI-3424), OBI’s novel ADC enabling technologies (GlycOBI® and ThiOBI®), and Globo H science

TAIPEI, Taiwan, April 23, 2025 (GLOBE NEWSWIRE) -- OBI Pharma, Inc. (TPEx: 4174. TWO) today announced nonclinical data for OBI-902, a potential best-in-class anti-TROP2 ADC developed using the next generation proprietary GlycOBI^® technologies. OBI-902 demonstrated superior antitumor activity and favorable PK/PD properties compared to benchmark TROP2 ADCs across various animal models. OBI-992, a cysteine-based TROP2 targeting ADC, demonstrated a differentiated resistance profile compared to benchmark ADCs. Additionally, characterization and non-clinical in vivo data will be presented for the glycan-specific GlycOBI^® and cysteine-based ThiOBI^® proprietary ADC platforms, highlighting enhanced antitumor activity and stability in animal model studies. ThiOBI^® is a new next-generation platform and adds to OBI’s armamentarium of ADC enabling technologies. Additionally, the non-clinical and antitumor activity of OBI-3424, a novel AKR1C3 targeted prodrug, will be presented. Furthermore, the potential correlation between GH expression and poor prognosis in cholangiocarcinoma (CCA), along with GH's role in modulating immune responses in CCA patients will be discussed.

These data will be presented at the American Association of Cancer Research (AACR) Annual Meeting from April 25 to 30, 2025 in Chicago, Illinois (USA).

“Our data demonstrated that OBI-902, derived from a site-specific GlycOBI^® platform, showed favorable PK and differentiated profiles with good ADC stability in circulation, and efficient payload release in the tumor site of tumor bearing mouse. In the xenograft models, OBI-902 demonstrated both superior and more durable antitumor activity compared to benchmark ADCs. The GlycOBI^® platform represents a breakthrough in antibody-drug conjugate (ADC) development as a distinct glycan site-specific technology, enabling a versatile drug-antibody ratio (DAR) and dual payload conjugations. The GlycOBI^® platform consists of both EndoSymeOBI^® enzyme and HYPrOBI™ linker technologies. The EndoSymeOBI^® dual function enzyme technology enables a precise glycan remodeling for site-specific conjugation through a “one-pot” process. The HYPrOBI™ technology provides a masking effect to reduce payload hydrophobicity, while the shielding effect enhances controlled payload release, specifically in tumor environments to prevent premature release in circulation. Notably, this technology can achieve a drug-antibody ratio (DAR) as high as 16, which is the highest DAR that can be achieved in site-specific glycan platforms.” said OBI’s Chief Scientific Officer, Ming-Tain Lai, Ph.D. “Furthermore, the ThiOBI^® platform was developed utilizing an irreversible cysteine conjugation alongside the HYPrOBI™ technology, to improve stability and prevents premature payload release. ADCs derived from the ThiOBI^® platform demonstrated superior antitumor activity compared to traditional cysteine benchmark ADCs.”

In collaboration with the National Cancer Institute (NCI), part of the National Institutes of Health, Pediatric Preclinical In Vivo Testing (PIVOT) Program, OBI-3424 was evaluated for its antitumor activity across a panel of pediatric hepatoblastoma PDX models by PIVOT research teams at Memorial Sloan-Kettering Cancer Center and the University of Texas Health Science Center at San Antonio, yielding promising results.

Monday, April 28,2025

Title: OBI-992, a novel TROP2 antibody-drug conjugate, exhibits distinct resistance profiles compared to other TROP2 targeting ADCs 1

Authors: Lifen Shen, Tzer-Min Kuo, Yu-Hsuan Tsao, Ya-Chi Chen, Ming-Tain Lai. OBI Pharma, Inc, Taipei, Taiwan

Session Title: PO. ET03.06 - Drug Resistance in Molecular Targeted Therapies 2
Location: Poster Section 20
Poster Board Number 3
Abstract Presentation Number 1702
Session Date and Time: Monday April 28, 2025. 9:00 AM - 12:00 PM

Title:Harnessing the GlycOBI^® enabling technologies: next-generation site-specific glycan ADCs with versatile DAR to enhance therapeutic index 2

Authors: Teng-Yi Huang, Ka-Shu Fung, Yu-Chao Huang, Chi-Sheng Shia, Chi-Huan Lu, Nan-Hsuan Wang, Ya-Chi Chen, Ming-Tain Lai. OBI Pharma, Inc, Taipei, Taiwan

Session Title: PO.ET02.08 - Novel Drug Delivery Technologies
Location: Poster Section 23
Poster Board Number 18
Abstract Presentation Number 1799
Session Date and Time: Monday, April 28, 2025. 9:00 AM - 12:00 PM

Tuesday, April 29, 2025

Title: OBI-902, a novel TROP2 targeted antibody-drug conjugate via GlycOBI^® platform, has favorable pharmacokinetics and sustained antitumor activities in challenging solid tumors.3

Authors: Ren-Yu Hsu, Chi-Huan Lu, Chi-Sheng Shia, Hsin-Shan Wu, Lu-Tzu Chen, Jhih-Jie Yang, Jyy-Shiuan Tu, Hui-Wen Chang, Shih-Ni Wen, Ming-Tain Lai, Ya-Chi Chen. OBI Pharma, Inc., Taipei, Taiwan

Session Title: PO.ET07.01 - Pharmacokinetics and Pharmacodynamics of Cancer Therapeutics
Location: Poster Section 20
Poster Board Number: 21
Abstract Presentation Number: 4356
Session Date and Time: Tuesday, April 29, 2025. 9:00 AM - 12:00 PM

Title: Globo H Affects the immune tumor microenvironment in cholangiocarcinoma 4

Authors: Chih Chieh Yen, Tzer Min Kuo, Chun Jung Lin, Hung Wen Tsai, Wen Lung Wang, Chien Jui Huang, Ping Jui Su, Ting Kai Liao, I Ting Liu, Li Chin Cheng, Ying Jui Chao, Yan Shen Shan, Chia Jui Yen, Ming Tain Lai. National Cheng Kung University Hospital, Tainan, Taiwan, OBI Pharmaceuticals Inc., Taipei, Taiwan, National Cheng Kung University Hospital, Tainan, Taiwan, National Cheng Kung University Hospital, Tainan, Taiwan, National Cheng Kung University Hospital, Tainan, Taiwan, Chi Mei Medical Center, Tainan, Taiwan

Session Title: PO.CL13.01 - Molecular Diagnosis, Molecular Characterization and Theranostics of Tumors
Location: Poster Section 30
Poster Board Number: 17
Abstract Presentation Number: 4597
Session Date and Time: Tuesday, April 29, 2025. 9:00 AM - 12:00 PM

Title: ThiOBI^® platform, a novel hydrophilic linker for irreversible cysteine-selective biomolecular conjugation, demonstrated potent and durable antitumor activities in various animal models 5

Authors: Yu-Chao Huang, Ting-Wei Liu, Chi-Huan Lu, Ren-Yu Hsu, Nan-Hsuan Wang, Ya-Chi Chen, Ming-Tain Lai, Teng-Yi Huang. OBI Pharma, Inc, Taipei, Taiwan

Session Title: PO.ET02.10 - Novel Methods in Small Molecule and Biologics Drug Discovery
Location: Poster Section 22
Poster Board Number: 20
Abstract Presentation Number: 5675
Session Date and Time: Tuesday, April 29, 2025. 2:00 PM - 5:00 PM

Title: Potentiation of AKR1C3- and P53-dependent AST-3424* activity via PUMA-mediated degradation of Rad51 6

Authors: Jianxin Duan, Tianyang Qi, Yizhi Wang, Xing Liu, Zhaoqiang Lu, Jibing Yu, Xiaohong Cai, Anrong Li, Don Jung, Chen Xun, Yanbin Xie, Fanying Meng, Shukui Qin. Ascentawits Pharmaceuticals, LTD, Shenzhen, China, The First Affiliated Hospital of China Pharmaceutical University, Nanjing Tianyinshan Hospital, Hepatobiliary and Pancreatic Tumor Department., Nanjing, China, GI Cancer Center, Nanjing Tianyinshan Hospital affiliated to China Pharmaceutical University, Nanjing, China

Session Title: PO.ET09.14 - Novel Antitumor Agents 3
Location: Poster Section 21
Poster Board Number: 27
Abstract Presentation Number: 5649
Session Date and Time: Tuesday, April 29, 2025. 2:00 PM - 5:00 PM

Wednesday, April 30,2025

Title: Preclinical evaluation of the AKR1C3-activated alkylator OBI-3424 in hepatoblastoma: A report from the Pediatric Preclinical In Vivo Testing Consortium (PIVOT) 7
Authors: Filemon Dela Cruz, Andrew Kung, Raushan Kurmasheva, Peter Houghton, Daoqi You, Glorife Ibanez Sanchez, Steven Neuhauser, Tim Stearns, Jeff Chuang, Jee Young Kwon, Emily L. Jocoy, Yu-Jung Chen, Ming-Chen Yang, Beverly Teicher, Carol J. Bult, Malcolm A. Smith. Memorial Sloan Kettering, New York, NY, UT Health San Antonio, San Antonio, TX, The Jackson Laboratory, Bar Harbor, ME, The Jackson Laboratory, Farmington, CT, The Jackson Laboratory, Sacramento, CA, OBI Pharma, Taipei City, Taiwan, National Cancer Institute, Bethesda, MD, National Cancer Institute, Bethesda, MD

Session Title: PO.CL07.02 - Advances in Translational Pediatric Cancer Research
Location: Poster Section 28
Poster Board Number 20
Abstract Presentation Number 7050
Session Date and Time: Wednesday, April 30, 2025. 9:00 AM - 12:00 PM

The e-posters will be available for browsing at the AACR Annual Meeting beginning at 12:00 PM ET on April 25, as well as on the OBI Pharma website (www.obipharma.com) beginning on May 1.

^{1AACR Annual Meeting 2025Abstracts online} https://www.abstractsonline.com/pp8/#!/20273/presentation/2507
^{2AACR Annual Meeting 2025 Abstracts online}https://www.abstractsonline.com/pp8/#!/20273/presentation/3007
^{3 AACR Annual Meeting 2025 Abstracts online}https://www.abstractsonline.com/pp8/#!/20273/presentation/1103
^{4AACR Annual Meeting 2025 Abstracts online} https://www.abstractsonline.com/pp8/#!/20273/presentation/1534
^{5AACR Annual Meeting 2025 Abstracts online} https://www.abstractsonline.com/pp8/#!/20273/presentation/3773
^{6AACR Annual Meeting 2025 Abstracts online}https://www.abstractsonline.com/pp8/#!/20273/presentation/7337
^{7 AACR Annual Meeting 2025 Abstracts online}https://www.abstractsonline.com/pp8/#!/20273/presentation/6521

About OBI Pharma

OBI Pharma, Inc., is a clinical stage global oncology company that is headquartered in Taiwan and established in 2002. Its mission is to develop novel cancer therapeutic agents for patients with high unmet medical needs.

Using the company’s proprietary ADC enabling technologies, GlycOBI^®, powered by EndoSymeOBI^® and HYPrOBI™; OBI has created its novel ADC pipeline, including OBI-992, OBI-902, and OBI-904, targeting TROP2 and Nectin-4, respectively. To broaden the applicability of the linker technology, HYPrOBI™, OBI further developed a next-generation ThiOBI^® platform to enable cysteine-based conjugation. Additionally, the company’s novel first-in-class immuno-oncology portfolio targeting Globo H includes: two Globo H active immunotherapy vaccines, adagloxad simolenin (formerly OBI-822) and OBI-833. OBI’s pipeline also includes the first-in-class AKR1C3-targeted small-molecule prodrug OBI-3424, which selectively releases a potent DNA-alkylating antitumor agent in the presence of the aldo-keto reductase 1C3 (AKR1C3) enzyme that is highly expressed in tumors. Additional information can be found at www.obipharma.com.

About OBI-992 and OBI-902

OBI-992 and OBI-902 are TROP2-targeted antibody-drug conjugates (ADCs) that carries a potent topoisomerase I inhibitor payload to kill tumor cells. TROP2 is highly expressed in a variety of solid tumors such as lung, breast, ovarian, and gastric cancer, rendering it an ideal target for cancer therapy.

OBI-992 uses a unique hydrophilic, enzyme-cleavable linker that is stable in circulation but releases the cytotoxic payload inside tumor cells. OBI-902 is a novel site-specific glycan ADC using OBI proprietary GlycOBI^® platform with improved stability and hydrophilicity. Both OBI-992 and OBI-902 demonstrated remarkable antitumor efficacy, improved pharmacokinetic characteristics, and a favorable safety profile in various animal models. OBI-992 received US IND clearance in December 2023 and Phase 1/2 efficacy and safety human studies are ongoing. IND of OBI-902 was submitted to FDA on March 31^st, 2025.

The TROP2 targeting antibody was in-licensed from Biosion, Inc. www.Biosion.com, in December 2021. OBI Pharma owns ex-China commercial rights for OBI-992.

*About OBI-3424
OBI-3424 is a first-in-class novel chemotherapeutic prodrug by OBI Pharma, Inc. that is selectively converted by AKR1C3 to a potent DNA-alkylating agent that leads to selective killing of cancer cells. The Company acquired the worldwide rights (except for China, Hong Kong, Macao, Taiwan, Japan, South Korea, Singapore, Malaysia, Thailand, Turkey, and India; owned by Ascentawits as AST-3424) of OBI-3424 from Threshold Pharmaceuticals, Inc. in 2017. OBI-3424 has been granted Orphan Drug Designation for the treatment of Hepatocellular Carcinoma (HCC) and Acute Lymphoblastic Leukemia (ALL) by the US FDA in 2018. OBI Pharma, Inc. continues the collaboration of OBI 3424 with Ascentawits through the sharing of clinical data and information.

About GlycOBI^®

OBI has developed a unique glycan ADC platform (GlycOBI^®), which are in a ‘Plug and Play’ format and compatible with any antibodies, linkers, and payloads in various Drug antibody ratio (DAR). Utilizing OBI’s proprietary enzymatic technology (EndoSymeOBI^®) and linker technology (HYPrOBI™), GlycOBI^® generates site-specific homogenous ADCs with an efficient and scalable process under GMP conditions. The conjugation process of GlycOBI^® avoids disrupting the antibody structure and ensures the ADC has similar biophysical characteristics to the native antibody. Furthermore, OBI’s linker technology has improved conjugation efficiency of the payload and reduced aggregation propensity, and also expanded the half-life of the ADC products. GlycOBI^® has overcome the limitations of traditional ADCs and achieved better antitumor activity and stability in various in vivo tests.

GlycOBI ^® and EndoSymeOBI ^® are registered trademarks of OBI Pharma. Inc. HYPrOBI™ is a trademark under registration.

About ThiOBI^®

OBI has developed a novel irreversible cysteine conjugation ADC platform (ThiOBI^®) with improved stability, which can apply to any antibodies, linkers, and payloads. Utilizing OBI’s proprietary ThiOBI^® platform including linker technologies (HYPrOBI™) can generate ADCs in different biomolecular formats, including antibody fragments, nanobodies, peptides, and proteins. Furthermore, OBI’s HYPrOBI™ linker technology has improved conjugation efficiency of the payload and reduced aggregation propensity, and also expanded the half-life of the ADC products. ThiOBI^® has overcome the limitations of traditional cysteine ADCs and achieved better antitumor activity and stability in various in vivo tests.

ThiOBI^® is a registered trademark of OBI Pharma. Inc.

Forward-Looking Statements

Statements included in this press release that are not a description of historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include, but are not limited to, statements about future clinical trials, results and the timing of such trials and results. Such risk factors are identified and discussed from time to time in OBI Pharma’s reports and presentations, including OBI Pharma’s filings with the Taiwan Securities and Futures Bureau.

COMPANY CONTACT:
Kevin Poulos, CBO
OBI Pharma, Inc.
1.619.537.7698 Ext. 102
kpoulos@obipharmausa.com