On April 18, 2026 Pliant Therapeutics, Inc. (Nasdaq: PLRX) reported the presentation of updated data from its Phase 1 trial of PLN-101095, in combination with pembrolizumab, in patients with immune checkpoint inhibitor (ICI)-refractory advanced or metastatic solid tumors. The oral presentation was made at the Clinical Trials Mini Symposium of the American Association for Cancer Research (AACR) (Free AACR Whitepaper) 2026 Annual Meeting.

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Timothy A. Yap, MBBS, Ph.D., Medical Oncologist and Physician-Scientist at the University of Texas MD Anderson Cancer Center, presented results from the dose escalation portion of the ongoing Phase 1a/1b trial covering data as of February 27, 2026. Results showed that in the heavily pretreated ICI-secondary refractory patient subgroup, twice daily (BID) treatment with PLN-101095 at the highest doses in combination with the ICI pembrolizumab showed antitumor activity. One confirmed overall complete response, two confirmed overall partial responses, including one patient with a complete response of baseline target lesions, and one unconfirmed partial response were reported in patients with cholangiocarcinoma, non-small cell lung cancer (NSCLC), melanoma and head and neck squamous cell carcinoma, respectively. As of the data cutoff date, the median time on treatment for the three confirmed responders was 19 months, who experienced an average baseline target tumor reduction of 89%.

All responding patients showed large increases (4- to 13-fold vs. baseline) in plasma interferon gamma (IFN-γ) after a 14-day run-in period of monotherapy with PLN-101095. At Week 10, all responders maintained more than a 2-fold increase in IFN-γ. No non-responders showed meaningful increases in IFN- γ. In addition to IFN- γ increases, all responding patients showed elevated plasma PD-L1 levels, known to be induced by increased IFN-γ and a predictor of an improved ICI response. As increases in IFN-γ have the potential to serve as a biomarker of TGF-β inhibition and an early indicator of PLN-101095 anti-tumor activity. Pliant anticipates further study of this biomarker as part of the expansion cohorts in the Phase 1b trial.

PLN-101095 was generally well tolerated across all doses evaluated with few discontinuations (n=2) due to adverse events. Rash was the most common treatment-related adverse event (TRAE), all Grade 1 or 2, and the majority of events occurred within the first 2 days of the initial pembrolizumab dose. One Grade 3 TRAE was observed.

PLN-101095 demonstrated a dose-ordered exposure at Day 14 with doses ≥1000 mg BID achieving sustained IC90 coverage and all participants dosed at ≥1000 mg BID maintaining IC75 coverage over 24 hours. These results support the consistent target engagement of PLN-101095.

Sixteen patients with ten different tumor types, including both primary and secondary refractory patients, were enrolled in five dose cohorts. Patients were treated for 14 days with PLN-101095 monotherapy administered orally at doses of 250 mg twice a day (BID) (n=1), 500 mg BID (n=2), 1000 mg BID (n=6), 1000 mg three times a day (TID) (n=4) or 2000 mg BID (n=3), followed by the addition of pembrolizumab at 200 mg administered intravenously every three weeks until disease progression. Scans were conducted at baseline, Day 14, Week 10, and every 8 weeks thereafter.

Dr. Yap commented "One of the ways that the tumor microenvironment can suppress responses to immune checkpoint inhibitors is through a process that is activated by integrins to upregulate TGF-β. PLN-101095 is designed to inhibit the integrins before they can ever do that, which gives it significant potential to stimulate or reinvigorate the immune response to cancer. These clinical trial data, for the combination of PLN-101095 and pembrolizumab in patients with secondary immune checkpoint inhibitor resistance, show the potential to meet a high unmet therapeutic need."

"These encouraging results show a deepening of baseline tumor reductions in confirmed responders and an increased median time on treatment with PLN-101095 in patients with difficult-to-treat ICI refractory tumors," said Bernard Coulie, M.D., PhD., Chief Executive Officer of Pliant. "We have initiated the Phase 1b trial to expand this novel combination therapy in specific tumor types to address patients in need and deliver value to our investors."

Slides accompanying these data can be found here and under the Investors & Media page of Pliant’s website at www.PliantRx.com.

PLN-101095 Phase 1b Indication Expansion Trial

Pliant has initiated a Phase 1b open-label indication expansion trial enrolling three cohorts of patients with NSCLC, tumors with high tumor mutational burden or clear cell renal cell carcinoma. Patients will be treated for 14 days with PLN-101095 dosed at 1,000 mg twice daily as monotherapy, after which pembrolizumab will be added as combination therapy. Enrollment is underway with interim data expected in 2027.

PLN-101095 for the Treatment of Checkpoint Resistant Tumors

PLN-101095 is an oral, small molecule inhibitor of integrins αvβ8 and αvβ1. PLN-101095 is being evaluated in Phase 1a/1b open-label, dose-escalation and indication expansion trial to evaluate the safety, tolerability, pharmacokinetics, and preliminary evidence of antitumor activity of PLN-101095 in combination with pembrolizumab, in patients with immune checkpoint inhibitor (ICI)-refractory advanced or metastatic solid tumors. Activated transforming growth factor-β (TGF-β) has been shown to foster an immuno-suppressive tumor microenvironment (TME) that contributes to immune-checkpoint inhibitor (ICI) resistance and treatment failure in cancer.1 Blocking integrins αvβ8 and αvβ1 has been shown to prevent the activation of TGF-β and is expected to stimulate immune activation by increasing immune cell infiltration into the tumor microenvironment.2,3 PLN-101095 in combination with an anti-PD-1 monoclonal antibody (mAb) elicited a dose-dependent reduction in tumor volume and increased CD8+ T cell tumor infiltration in the tumor microenvironment compared with anti-PD-1 mAb therapy alone.4 In preclinical studies, PLN-101095 demonstrated monotherapy activity in reduction of tumor volume and increased cluster of differentiation (CD)8+ T cell infiltration.

(Press release, Pliant Therapeutics, APR 18, 2026, View Source [SID1234664529])

On April 18, 2026 Moderna, Inc. (NASDAQ:MRNA) reported that the Company will present data from a Phase 1/2 study of mRNA-4359, an investigational cancer antigen therapy, at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting in San Diego, CA, on April 17-22, 2026. The presentation reports safety, efficacy and translational data from a Phase 2 dose-expansion cohort of the Phase 1/2 study (NCT05533697), which evaluated mRNA-4359 + pembrolizumab as a first-line therapy in patients with locally advanced or metastatic melanoma.

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Among 12 participants, mRNA-4359 + pembrolizumab resulted in an overall response rate (ORR) of 83% (95% CI: 52%-98%), with two patients achieving a complete response and eight achieving a partial response, as well as a disease control rate (DCR) of 92% (95% CI: 62%-100%). The median time to response was six weeks (range, 5.6-24.0). Responses occurred across baseline tumor PD-L1 expression categories, with an ORR of 88% (95%CI: 47%-100%) among patients with PD-L1+ (TPS≥1%) tumors, and 67% (95%CI: 9%-99%) among patients with PD-L1- (TPS<1%) tumors. Consistent with mRNA-4359’s mechanistic rationale, antigen-specific T-cell responses and novel expanded T-cell receptor (TCR) clonality was observed in all patients (n=7) with evaluable samples. mRNA-4359 + pembrolizumab demonstrated a manageable safety profile, with no new immune-related adverse events (AEs).

"This study evaluating mRNA-4359 + pembrolizumab as a first-line treatment option reflects our ambition to demonstrate the potential of mRNA technology throughout a cancer patient’s journey. While conducted among a small patient population, we are encouraged by the high response rates and mechanistic translational results," said David Berman, M.D., Ph.D., Chief Development Officer of Moderna. "We look forward to further evaluating the potential of mRNA-4359 in patients with melanoma."

"This early data supports the potential activity of the mRNA-4359 + pembrolizumab combination, with promising anti-tumor activity," Dr. Pavlina Spiliopoulou, School of Cancer Sciences, University of Glasgow, the abstract’s lead author and presenter. "The consistent activation of antigen-specific T-cell responses provides important early evidence that mRNA technology could be used to help direct the immune system against melanoma in a multi-targeted manner."

This presentation builds on promising early data presented at the 2025 European Society for Medical Oncology Congress, in which mRNA-4359 + pembrolizumab achieved an ORR of 24% and DCR of 60% among 29 evaluable patients with checkpoint inhibitor-resistant/refractory (CPI-R/R) melanoma. Among those with response-evaluable disease and PD-L1+ (TPS≥1%) tumors, the ORR was 67%.

The U.S. FDA has granted Fast Track designation for mRNA-4359 in combination with pembrolizumab for the treatment of CPI refractory unresectable or metastatic melanoma with PD-L1+ (TPS>1%). Fast Track is designed to facilitate the development and expedite the review of therapies and vaccines for serious conditions and that fill an unmet medical need. Programs with Fast Track designation may benefit from early and frequent communication with the FDA, in addition to a rolling submission of the marketing application.

The details of the presentation are as follows:

Abstract Presentation #CT106: First-Line mRNA-4359 Plus Pembrolizumab (Pembro) in Locally Advanced or Metastatic Melanoma: Results from the Phase 1/2 mRNA-4359-P101 Study

Session Title: Clinical Trials Plenary 3: Cellular Therapies and Complex Immunotherapies

Session Date/Time: Monday, April 20, 10:15AM – 12:15PM PT

Presenter: Dr. Pavlina Spiliopoulou, School of Cancer Sciences, University of Glasgow, UK

About mRNA-4359

mRNA-4359 is an investigational, immune-evasion targeted cancer antigen therapy that encodes broad epitopes of PD-L1 and IDO1. With its dual mechanism of action, it is designed to elicit antigen-specific T-cell responses to simultaneously: (1) kill tumor cells expressing PD-L1 and IDO1, and (2) deplete immunosuppressive cells that shield the tumor from attack. This is hypothesized to rebalance the tumor microenvironment into an immune-permissive state, supporting sustained and durable anti-tumor activity with a manageable safety profile.

(Press release, Moderna Therapeutics, APR 18, 2026, https://feeds.issuerdirect.com/news-release.html?newsid=8054079664924385&symbol=MRNA [SID1234664479])

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])

On April 17, 2026 Pheast Therapeutics, a clinical-stage biotechnology company advancing macrophage-directed immunotherapies for cancer, reported the presentation of initial Phase 1a clinical data and new preclinical findings for PHST001, an IgG4 anti-CD24 macrophage checkpoint inhibitor, at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026.

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"The data presented at AACR (Free AACR Whitepaper) suggest that PHST001 may address a longstanding challenge in translating the therapeutic potential of macrophage biology into a cancer treatment with the right balance of activity and tolerability," said Roy Maute, Ph.D., CEO and Co-founder of Pheast Therapeutics. "The preclinical data further support rationally designed therapeutic combinations informed by CD24 biology, reinforcing the breadth of PHST001’s development potential."

In the ongoing Phase 1a first-in-human study, PHST001 was generally well-tolerated across dose-escalation cohorts. Most treatment-related adverse events were Grade 1 or 2, with a subset of patients experiencing transient neutrophil decreases that were manageable and not associated with clinical complications. The dataset demonstrated linear pharmacokinetics, increasing CD24 receptor occupancy at higher dose levels, and pharmacodynamic changes consistent with innate immune activation. Early signs of clinical activity were observed, including disease stabilization and tumor shrinkage.

In preclinical studies including patient-derived tumor xenograft models, PHST001 enhanced macrophage-mediated tumor control and prolonged survival in combination with chemotherapies and antibody-drug conjugates. PHST001 also inhibited metastatic spread and reduced metastatic burden across multiple in vivo models.

"Taken together, these clinical and preclinical findings begin to build the profile we are looking for in a macrophage checkpoint inhibitor: favorable tolerability, evidence of biological activity, and meaningful combination potential," said Raphaël Rousseau, M.D., Ph.D., Chief Medical Officer of Pheast Therapeutics. "These data support continued development of PHST001 as a monotherapy and in combination with cytotoxic agents, where it may enhance macrophage-mediated clearance of treatment-damaged tumor cells."

Pheast plans to present updated clinical data from the ongoing PHST001-101 study at a future medical meeting.

The AACR (Free AACR Whitepaper) posters can be viewed at https://www.pheast.com/pipeline.

About CD24

CD24 is a cell surface protein that plays a key role in tumor immune evasion by engaging Siglec-10, an inhibitory receptor on macrophages. This interaction suppresses macrophage-mediated clearance of cancer cells, allowing tumors to evade destruction by the innate immune system. CD24 was identified as a novel macrophage checkpoint through foundational work by Dr. Amira Barkal, principal founder of Pheast. Along with other co-founders, Drs. Irving Weissman, Ravi Majeti, and Roy Maute, Pheast’s research forms the basis for therapeutic strategies targeting CD24 to activate innate immune responses against cancer.

About PHST001

PHST001 is an anti-CD24 macrophage checkpoint inhibitor designed to overcome immune suppression in the tumor microenvironment. CD24 is highly expressed in many human cancers and high expression of CD24 is associated with poor prognosis across multiple tumor types. PHST001 is designed to promote macrophage-mediated phagocytosis of cancer cells and initiate a broader immune response. PHST001-101 is an open-label, multicenter Phase 1 study in patients with advanced solid tumors (ClinicalTrials.gov Identifier: NCT06840886). Primary objectives include safety, tolerability, and dose optimization, with secondary objectives evaluating pharmacokinetics and preliminary anti-tumor activity. PHST001 received FDA Fast Track Designation for the treatment of ovarian cancer in June 2025. The phase 1b portion of the study combining PHST001 with chemotherapies is actively recruiting patients.

(Press release, Pheast Therapeutics, APR 17, 2026, View Source [SID1234664512])