On April 17, 2026 Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical-stage biotechnology company discovering and developing masked immuno-oncology therapies for people living with cancer, reported new preclinical data for XTX601, a masked T cell engager targeting claudin 18.2 (CLDN18.2), at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting, taking place from April 17–22, 2026 at the San Diego Convention Center in San Diego, California.

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"The data to be presented at AACR (Free AACR Whitepaper) underscore the significant potential of our clinically-validated masking technology to address the central challenge that has limited the advancement of T cell engagers in solid tumors – namely, the inability to achieve meaningful anti-tumor activity without inducing severe systemic toxicities," said Uli Bialucha, Ph.D., chief scientific officer of Xilio Therapeutics. "XTX601 has demonstrated a promising preclinical profile, including potent tumor cell killing across multiple CLDN18.2-expressing tumor models and a favorable tolerability profile in non-human primates, supporting its potential to achieve a wide therapeutic index. Importantly, our modular architecture for masked T cell engagers provides flexibility to rapidly evaluate multiple designs in parallel, including masking of the CLDN18.2 binding domain and/or the addition of a co-stimulatory domain, which enables us to seek to optimize the molecule for the best possible clinical profile."

Masked T Cell Engager Design

XTX601 is a potentially first-in-class masked T cell engager designed to selectively target CLDN18.2, a tumor-associated antigen expressed in gastric, pancreatic and esophageal cancers. XTX601 incorporates Xilio’s clinically-validated masking technology and advanced tumor-activated cell engager (ATACR) format, which consists of a T cell engager with a masked CD3 targeting domain, with the goal of minimizing systemic T cell engagement in healthy tissue and overcoming the significant systemic toxicities that have limited non-masked T cell engagers targeting CLDN18.2. In addition, XTX601 is designed with a conditional half-life modulation element for antibody-like pharmacokinetics in its masked state and a short half-life upon activation in the tumor microenvironment to further limit peripheral exposure.

Preclinical Data Highlights Presented at AACR (Free AACR Whitepaper)

In preclinical studies, XTX601 demonstrated the potential to achieve a wide therapeutic index.

XTX601 demonstrated protease-dependent activation and tumor cell killing in high- and low-expression settings for CLDN18.2, with effective masking of the anti-CD3 domain.
XTX601 exhibited robust, dose-dependent anti-tumor activity in multiple murine cell line-derived xenograft models, including GSU gastric carcinoma and OE19 esophageal adenocarcinoma models engrafted with human T cells.
Consistent with its masked design, XTX601 was well tolerated in non-human primates (NHP) with no evidence of cytokine release syndrome and no changes in liver enzymes.
Integration of drug exposure data from murine tumor models and NHP studies indicated a favorable, positive therapeutic index for XTX601 and supports the potential for XTX601 to achieve meaningful anti-tumor activity at doses that are well-tolerated systemically.

Xilio plans to advance its masked T cell engager program targeting CLDN18.2 into investigational new drug (IND)-enabling studies and submit an IND application for this program in 2027.

Presentation Details

Xilio’s poster presentation at AACR (Free AACR Whitepaper) is listed below, and a copy of the presentation will be available under the "Our Approach—Presentations & Publications" section of the company’s website at www.xiliotx.com.

Title: Discovery and Optimization of XTX601, a Masked Claudin 18.2-Targeting T Cell Engager
Session Category: Immunology
Session Title: T Cell Engagers 1
Session Date and Time: Monday, Apr. 20, 2026, from 9:00 a.m. to 12:00 p.m. PST
Location: Poster Section 10, Poster Board 11
Abstract Number: 1619

(Press release, Xilio Therapeutics, APR 17, 2026, View Source [SID1234664510])

On April 17, 2026 Onchilles Pharma, a private biotech company advancing therapeutics targeting the ELANE pathway, reported new preclinical data from its NEU-002 program presented at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026. The poster highlights the translational development of NEU-002, an engineered therapeutic elastase program intended for systemic administration, and demonstrates anti-tumor activity following both intravenous (IV) and intraperitoneal (IP) delivery in preclinical solid tumor models.

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"NEU-002 is designed to bring the ELANE pathway to more solid tumor indications that are not well served by local delivery," said Court R. Turner, J.D., Co-Founder and Chief Executive Officer of Onchilles Pharma. "The preclinical data presented at AACR (Free AACR Whitepaper) show anti-tumor activity after both IV and IP administration and move us closer to a systemic approach intended to kill tumors while preserving the immune response needed for durable control."

The data presented at AACR (Free AACR Whitepaper) show that candidates from the systemically delivered NEU-002 program achieved tumor biodistribution and anti-tumor activity in preclinical CT26 colon cancer models following both IV and IP administration. In a CT26 flank model, IV-delivery of a NEU-002 candidate drove complete tumor clearance in all treated animals and durable protection across multiple tumor rechallenges, consistent with long-term immune memory. In a separate CT26 visceral model, IP-delivery of a NEU-002 candidate reduced ascites and total tumor burden, supporting the potential of these NEU-002 candidates in settings relevant to disseminated abdominal disease.

NEU-002 was developed to extend the ELANE pathway beyond tumor-directed delivery through engineering intended to protect elastase activity against circulating serine protease inhibitors. Together, these findings support continued advancement of the NEU-002 program as a systemic approach for solid tumors, with two lead candidates moving forward for additional evaluation, including into non-human primate pharmacokinetic studies, to inform final development candidate selection.

About Onchilles Therapeutic Programs Targeting the ELANE Pathway

At the core of this approach is the ELANE pathway, a unique cancer-selective killing mechanism that leverages a vulnerability shared by many cancer cell types: elevated histone H1 levels. Our pipeline is led by N17350, our first-in-class, clinical-stage program, followed by NEU-002, the second program that extends this approach with systemic delivery. By targeting the ELANE pathway and inducing immunogenic cancer cell death, N17350 and NEU-002 are designed to rapidly eliminate tumors while mobilizing an adaptive immune response, offering the potential for sustained anti-tumor immunity. N17350 and NEU-002 offer a unique approach to treating cancer regardless of their genetic makeup, anatomical origin, or immune status, positioning them as potential gamechangers in cancer therapy.

(Press release, Onchilles Pharma, APR 17, 2026, View Source [SID1234664495])

On April 17, 2026 Zymeworks Inc. (Nasdaq: ZYME), a biotechnology company managing a portfolio of licensed healthcare assets while developing a diverse pipeline of novel, multifunctional biotherapeutics, reported six poster presentations featuring new preclinical data from its antibody-drug conjugate (ADC) and payload development programs at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026.

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"Our AACR (Free AACR Whitepaper) presentations highlight the breadth and depth of our ADC platforms, including multiple novel approaches to targeting RAS-driven cancers," said Paul Moore, Ph.D., Chief Scientific Officer at Zymeworks. "These data reinforce our strategy to develop differentiated therapeutics with the potential to improve efficacy while addressing key limitations of existing treatment approaches."

Poster Presentation Highlights

ZW191 – a differentiated FRα-targeted topoisomerase I antibody drug conjugate active in combination with standard of care drugs
Abstract: 1707
Session: Experimental and Molecular Therapeutics

ZW191 is a clinical-stage (NCT06555744) folate receptor alpha (FRα)-targeting antibody-drug conjugate featuring a novel antibody and a moderate-potency, bystander-active topoisomerase I inhibitor payload (TOPO1i), ZD06519, designed to drive improved efficacy and tolerability versus existing FRα-targeted ADCs. In nonclinical studies, ZW191 demonstrates activity across all levels of FRα expression and shows promising combination potential with standard-of-care therapies, supported by a favorable tolerability profile.

Key non-clinical findings include:

Differentiated by its superior internalizing novel antibody and moderate potency novel TOPO1i payload.
Favorable tolerability profile, attributed to moderate potency TOPO1i payload and moderate stability linker, potentially achieves higher ADC dosing, better tolerability and improved combination potential with standard of care chemotherapeutics.
Nonclinical in vitro and in vivo studies support the efficacious combination of ZW191 with standard of care therapies across multiple modes of action.
A pan-RASi antibody drug-conjugate platform with high activity in RAS sensitive cancers
Abstract: 1642
Session Category: Experimental and Molecular Therapeutics

Zymeworks’ RASi-ADC platform integrates novel tricomplex pan-RAS inhibitors into ADCs to enable tumor-selective delivery and improved therapeutic index.

Key findings include:

Strong regressions observed in multiple tumor models at single doses as low as 1 mg/kg
ADC delivery demonstrates improved tumor selectivity compared to orally administered RAS inhibitors
Favorable tolerability observed in rodents and non-human primates
Platform supports development of broadly applicable ADCs for RAS-mutated cancers
Development of ZW418, a biparatopic PTK7-targeting antibody-drug conjugate incorporating a novel pan-RAS inhibitor payload for the treatment of non-small cell lung cancer
Abstract: 4944
Session Category: Experimental and Molecular Therapeutics

ZW418 is a first-in-class biparatopic ADC targeting PTK7, designed to enhance binding, internalization, and delivery of a pan-RAS inhibitor payload in non-small cell lung cancer (NSCLC).

Key findings include:

Strong anti-tumor activity observed across PTK7-expressing RAS-mutant NSCLC xenograft models, at doses as low as 1 mg/kg
Biparatopic design enhances receptor engagement, internalization, and payload delivery
Selective cytotoxicity in KRAS-mutant tumor cells while sparing normal tissues
Favorable pharmacokinetics and tolerability support further development
ZW427, a Ly6E-targeting antibody-drug conjugate bearing a novel pan-RAS inhibitor payload for the treatment of RAS mutated cancers
Abstract: 7715
Session Category: Experimental and Molecular Therapeutics

ZW427 is a first-in-class ADC targeting Ly6E, designed to deliver a novel pan-RAS inhibitor payload to tumor cells in colorectal (CRC), pancreatic (PDAC), and lung cancers.

Key findings include:

Robust anti-tumor activity observed across CRC, PDAC, and NSCLC xenograft models with a range of Ly6E expression
Targeted delivery enables sustained RAS inhibition in tumors with reduced activity in normal tissues such as skin and colon
Favorable tolerability observed in rodents and non-human primates at exposures exceeding projected efficacious doses
Potential to improve efficacy and safety profile compared to small molecule pan-RAS inhibitors
ZW439, a novel CLDN18.2-targeting pan-RAS inhibitor antibody-drug conjugate for the treatment of RAS mutated pancreatic cancer
Abstract: 4556
Session Category: Experimental and Molecular Therapeutics

ZW439 is a novel ADC targeting CLDN18.2, designed to deliver a pan-RAS inhibitor payload in pancreatic ductal adenocarcinoma.

Key findings include:

Strong anti-tumor activity observed in CLDN18.2-expressing RAS-mutant xenograft models, at doses as low as 1 mg/kg
Target-dependent delivery of pan-RAS inhibitor payload with potent RAS pathway inhibition and cytotoxicity
Robust bystander activity supports activity in heterogeneous tumors
Favorable pharmacokinetics and tolerability compared to small molecule RAS inhibitors
Design and evaluation of mRNA translation inhibitors for use as antibody drug conjugate payloads
Abstract: 2062
Session Category: Experimental and Molecular Therapeutics

Zymeworks presented a novel class of eIF4A inhibitor payloads designed to inhibit mRNA translation and enable a new mechanism for ADC therapies.

Key findings include:

Over 40 novel eIF4A inhibitor payloads synthesized spanning a range of potency and hydrophilicity
Hydrophilic linker designs improve both efficacy and tolerability in vivo
Demonstrated robust anti-tumor activity across multiple targets including HER2, TROP2, EGFR, Ly6E, and PTK7
Represents a novel payload class with potential to overcome resistance to existing ADC payloads
Posters are available on the Company’s website located at View Source." target="_blank" title="View Source." rel="nofollow">View Source

Oral Presentation Details

Results from Part 1 dose escalation of ZWI-ZW191-101 study: Phase 1 first-in-human multicenter open-label study of ZW191, a folate receptor α (FRα)–targeting antibody-drug conjugate (ADC), in participants with advanced solid tumors
Abstract: CT306
Session: Advances in Precision Oncology

Lead author Patricia LoRusso, DO, PhD (hc), FAACR will present an updated data cut from the late breaking abstract on Tuesday, April 21, 2026 at 2:30 – 4:30 pm Pacific Standard Time (PST). The presentation will be available on the Company’s website located at View Source at the time of the session.

(Press release, Zymeworks, APR 17, 2026, View Source [SID1234664511])

On April 17, 2026 SK Life Science Labs, a subsidiary of SK Biopharmaceuticals Co., Ltd., a global biotech focused on the research, development, and commercialization of treatments for disorders of the central nervous system (CNS) and cancer, reported the presentation of three posters at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026, taking place April 17–22 in San Diego, California.

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The presentations highlight SK Life Science Labs’ continued progress in advancing targeted protein degradation approaches against key oncology targets, including p300 and PRMT5, with the potential to address unmet needs across multiple cancer types.

"Our latest findings further demonstrate the power of targeted protein degradation to selectively eliminate key cancer vulnerabilities with depth and precision that may not be achievable with traditional inhibition," said Ryan Kruger, Ph.D., Chief Scientific Officer at SK Life Science Labs. "We are particularly encouraged by the breadth of anti-tumor activity and improved safety profiles observed in our p300 and PRMT5 degrader programs, which underscore their potential to deliver meaningful therapeutic advances for patients."

Data to be presented include:

Selective p300 degraders in CBP mutant cancers, demonstrating deep anti-tumor activity with robust tumor regression across multiple preclinical models.
Selective p300 degraders in p300-dependent cancers, showing broad efficacy in prostate cancer and multiple myeloma models, with strong suppression of oncogenic transcriptional programs and improved tolerability versus dual inhibition approaches.
Next-generation PRMT5 activity modulation through rapid, potent, and selective degradation of PRMT5, enabling comprehensive suppression of its catalytic and non-catalytic functions and overcoming limitations associated with first- and second-generation inhibitors.
Poster Presentation Details (All times are PDT):

Session: PO.CH01.01 – Targeted Protein Degradation and Induced Proximity
Abstract 5178 / 28: Discovery and characterization of a selective p300 degrader reveals deep anti-tumor activity in CBP mutant cancers
Lead Author: Harshil D. Dhruv
Date/Time: April 21, 2026, 9:00 AM – 12:00 PM; Section 39
Session: PO.CH01.01 – Targeted Protein Degradation and Induced Proximity
Abstract 5179 / 29: Discovery and characterization of a selective p300 degrader reveals broad anti-tumor activity in p300-dependent cancers
Lead Author: Harshil D. Dhruv
Date/Time: April 21, 2026, 9:00 AM – 12:00 PM; Section 39
Session: PO.ET09.04 – Proximity-Induced Drug Discovery 2
Abstract 5790 / 17: Next-generation PRMT5 activity modulation through directed degradation
Lead Author: Jose C. Clemente
Date/Time: April 21, 2026, 2:00 PM – 5:00 PM; Section 15
For more information about SK Life Science Labs, visit www.sklslabs.com.

Frequently Asked Questions (FAQ)

What is SK Life Science Labs announcing at AACR (Free AACR Whitepaper) 2026?
SK Life Science Labs is presenting three posters showcasing new preclinical data from its targeted protein degradation pipeline, including programs focused on p300 and PRMT5.

What are the key programs being highlighted?
The company is presenting data on selective p300 degraders in both CBP mutant and p300-dependent cancers, as well as PRMT5 degraders designed to achieve deeper and more durable target modulation.

Why is p300 an important target in cancer?
p300 is a transcriptional co-activator involved in regulating gene expression in multiple cancers. Selective degradation of p300 enables precise targeting of tumor-driving pathways, particularly in cancers with CBP mutations or p300 dependency.

What differentiates SK Life Science Labs’ p300 degraders?
The company’s p300 degraders are designed to be highly selective, avoiding degradation of the closely related CBP protein. This selectivity may enable strong anti-tumor activity while reducing hematologic toxicity seen with dual p300/CBP inhibition.

What is the significance of targeting PRMT5 through degradation?
PRMT5 is an epigenetic regulator implicated in multiple cancers. Targeted degradation has the potential to eliminate both catalytic and non-catalytic functions of PRMT5, potentially overcoming limitations of traditional inhibitors and enabling more complete target suppression.

What stage of development are these programs in?
The p300 degrader program is currently progressing through IND-enabling studies and the PRMT5 program data are in support of ongoing research efforts to advance it toward potential clinical development.

What is targeted protein degradation?
Targeted protein degradation is a therapeutic approach that harnesses the body’s natural ubiquitin-proteasome system (UPS) to selectively identify and eliminate disease-causing proteins, including those that have historically been difficult to drug.

Where and when will the data be presented?
All three posters will be presented on April 21, 2026, during AACR (Free AACR Whitepaper) Annual Meeting poster sessions in San Diego, California.

(Press release, SK biopharmaceuticals, APR 17, 2026, View Source [SID1234664480])

On April 17, 2026 Orum Therapeutics ("Orum" or the "Company") (KRX: 475830), a biotechnology company pioneering the field of degrader-antibody conjugates (DACs), reported the presentation of new preclinical data for ORM-1153, a CD123-targeting DAC designed to selectively deliver a proprietary GSPT1-degrading payload, in development for the treatment of AML and other CD123-positive hematological malignancies. The data were presented in two posters at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026.

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"These data show strong preclinical activity and the potential for a differentiated safety and tolerability profile, supporting the advancement of ORM-1153 as a next-generation CD123-targeting degrader-antibody conjugate for acute myeloid leukemia," said Chad May, Ph.D., Chief Scientific Officer of Orum. "Our approach combines a proprietary CD123-antibody and novel GSPT1-targeted protein degrader with the goal of achieving greater selectivity than conventional cytotoxic antibody-drug conjugates. We believe this strategy can enable more effective and better-tolerated therapies for patients with AML."

The first poster (Abstract Number: 1824) highlights how ORM-1153 was engineered with a proprietary CD123-antibody designed for enhanced internalization and reduced Fc-gamma receptor interactions, together with a linker optimized for plasma stability, an approach intended to improve delivery, reduce off-target and immune cell engagement, and support favorable pharmacologic properties. Consistent with that design, ORM-1153 showed strong preclinical anti-leukemia activity at low doses, along with prolonged accumulation in tumors, undetectable systemic free payload, and favorable repeat-dose non-human primate findings supporting a manageable safety and tolerability profile.

Data from the second poster (Abstract Number: 1710) extend Orum’s previously presented findings by showing activity across primary AML patient samples and in models with relevant tumor mutations, including TP53. Taken together, the findings support the potential for broad activity in AML, including in patients with TP53 mutations.

"These AACR (Free AACR Whitepaper) data are particularly encouraging in the context of AML, where many patients, especially those with TP53 mutations, continue to have limited treatment options and poor outcomes," said Olaf Christensen, M.D., Chief Medical Officer of Orum. "The activity we are seeing across primary patient samples and TP53-relevant models, together with a consistent pharmacologic and tolerability profile, supports the continued advancement of ORM-1153 toward clinical development."

Both posters are available on Orum’s website and will be presented at AACR (Free AACR Whitepaper) on Monday, April 20, from 9 am to 12 pm PDT.

About ORM-1153

ORM-1153 is a CD123-targeting degrader-antibody conjugate developed using Orum’s Dual-Precision TPD² approach. The molecule is built from two proprietary elements, a GSPT1-degrading payload and an anti-CD123 antibody engineered for high internalization efficiency, conjugated with a cleavable β-glucuronide linker. By combining tumor-selective antibody delivery with targeted protein degradation, ORM-1153 is designed to induce cancer cell death through degradation of GSPT1, a protein implicated in cell survival, including in TP53-mutant AML, while minimizing effects on normal tissues.

About Orum’s TPD² Approach

Orum’s unique Dual-Precision Targeted Protein Degradation (TPD²) approach builds novel targeted protein degraders combined with the precise cell delivery mechanisms of antibodies to generate innovative, first-in-class, cell-selective TPDs for the treatment of cancer and other serious diseases. Orum has developed new targeted protein degrader payloads to specifically degrade an intracellular target protein within cancer cells via the E3 ubiquitin ligase pathway. Conjugated to antibodies, the payloads are designed to be delivered specifically to target cells and precisely degrade the intracellular target protein of interest.

(Press release, Orum Therapeutics, APR 17, 2026, View Source [SID1234664496])