PLRX

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Exhibit 99.1

Pliant Therapeutics Provides Corporate Update and Reports Third Quarter 2026 Financial Results

FORTIFY, a Phase 1b indication expansion trial of PLN-101095, continues strong enrollment

Pliant’s proprietary selective, targeted, integrin-mediated delivery platform demonstrates encouraging initial preclinical results

Strengthened leadership team with appointments of David Raben, M.D., as Chief Medical Officer and Craig Blanchette, Ph.D., as Senior Vice President, Research (RNAi).

SOUTH SAN FRANCISCO, CA., November 12, 2026 - Pliant Therapeutics, Inc. (Nasdaq: PLRX), a clinical-stage biotechnology company focused on the discovery and development of integrin-based therapeutics, today provided a corporate update and reported third quarter 2026 financial results.

“The third quarter reflected continued strong execution across the Organization, including robust FORTIFY enrollment and compelling proof-of-concept data generated from our integrin-mediated drug delivery platform,” said Bernard Coulie, M.D., Ph.D., President and Chief Executive Officer of Pliant. “FORTIFY continues to enroll ahead of schedule, with a number of European sites onboarded during the quarter. In addition, we continue to explore the potential of our proprietary drug delivery platform with cross-species preclinical data demonstrating successful selective delivery of siRNA payloads to extrahepatic tissues. With emerging data continuing to inform our next steps, potential therapeutic applications and paths forward, we will provide a comprehensive overview of the program in the coming months.”

Oncology Program

PLN-101095 is an oral, small molecule, dual selective inhibitor of αvβ8 and αvβ1 integrins designed to overcome checkpoint resistance by blocking TGF-β activation in the tumor microenvironment. Pliant is currently conducting FORTIFY, a Phase 1a/1b open-label, dose-escalation and indication expansion trial (NCT06270706), 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.

•Strong enrollment continues in FORTIFY, a Phase 1b indication expansion trial. FORTIFY will enroll up to 102 patients across three cohorts including non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (ccRCC) and tumors with high tumor mutational burden. Patients are treated for 14 days with PLN-101095 dosed at 1,000 mg twice daily as monotherapy, after which pembrolizumab is added as combination therapy. Enrollment remains strong, progressing ahead of schedule with active sites in the United States and Spain with additional countries onboarding in the next several months. Interim data is expected in 2027.

•Presentations at Annual Meeting of the Society for Immunotherapy of Cancer (SITC) highlight PLN-101095 Phase 1 biomarker data and mechanism of action.

◦Researchers from Pliant presented new biomarker data from the Phase 1 trial showing that early induction of immune activation biomarkers during PLN-101095 monotherapy was associated with subsequent clinical response following pembrolizumab initiation. These findings support the

hypothesis that TGF-β pathway inhibition promotes immune activation, T-cell recruitment into the tumor microenvironment, and enhanced cytotoxic effector function.

◦Researchers from the National Cancer Institute presented data demonstrating that the blockade of integrins αvβ8 and αvβ1 in combination with anti-PD-1 reduced TGF-β signaling leading to modulation of fibroblastic cell populations in the tumor microenvironment and increased infiltration and activation of cytotoxic CD8+ T cells. This resulted in an improvement in anti-tumor activity and survival.

Selective, Targeted, Integrin-mediated Delivery Platform

Utilizing our fully annotated library of 15,000+ integrin binding molecules, as well as our biological knowledge of cell-specific integrin receptor expression, Pliant has created a selective, targeted integrin-mediated delivery platform for cell- and tissue-selective extrahepatic delivery of drug payloads, including RNAi. The platform has broad applicability across multiple disease areas utilizing a variety of drug payloads.

•Tissue Specificity, Potency and Durability – Pliant has initiated multiple RNAi delivery programs targeting specific tissues through unique integrin expression profiles. The most advanced compounds to date selectively target skeletal and skeletal/cardiac muscle, respectively. In non-human primate studies, we have observed >75% target gene knockdown at eight weeks while avoiding liver and other non-targeted tissues.

•Plug-and-Play Compatibility – Pliant's integrin-directed small molecule delivery compounds can be loaded with RNAi payloads directed at any gene of interest. This allows a single compound to serve as the basis

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Exhibit 99.1

Pliant Therapeutics Provides Corporate Update and Reports Second Quarter 2026 Financial Results

FORTIFY, a Phase 1b indication expansion trial of PLN-101095,

experiencing strong enrollment

Appointed seasoned oncology drug development leaders

Flavia Borellini, Ph.D. and Robert Iannone, M.D., M.S.C.E. to Board of Directors

SOUTH SAN FRANCISCO, CA., August 11, 2026 - Pliant Therapeutics, Inc. (Nasdaq: PLRX), a clinical-stage biotechnology company focused on the discovery and development of integrin-based therapeutics, today provided a corporate update and reported second quarter 2026 financial results.

“In the second quarter, we continued to execute across the portfolio, led by strong enrollment in FORTIFY,” said Bernard Coulie, M.D., Ph.D., President and Chief Executive Officer of Pliant. “With the appointments of Flavia and Robert to the board, Pliant now has deep global oncology drug development and commercialization expertise at this important time for our oncology program. We continue to make progress on our proprietary integrin-targeted drug-delivery platform and look forward to sharing more information on the platform soon.”

Oncology Program

PLN-101095 is an oral, small molecule, dual selective inhibitor of αvβ8 and αvβ1 integrins designed to overcome checkpoint resistance by blocking TGF-β activation in the tumor microenvironment. Pliant is currently conducting FORTIFY, a Phase 1a/1b open-label, dose-escalation and indication expansion trial (NCT0670706), 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.

•Enrollment continues in FORTIFY, a Phase 1b indication expansion trial. FORTIFY will enroll up to 102 patients across three cohorts including non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (ccRCC) and tumors with high tumor mutational burden. Patients are treated for 14 days with PLN-101095 dosed at 1,000 mg twice daily as monotherapy, after which pembrolizumab is added as combination therapy. Enrollment remains strong, progressing ahead of schedule. Interim data is expected in 2027.

•Oral presentation at AACR of updated PLN-101095 Phase 1 data highlights monotherapy biomarker data showing a coordinated T-cell reactivation cascade in responders. In July, at the American Association for Cancer Research’s (AACR) Drug Discovery and Development conference, the Company reviewed encouraging PLN-101095 Phase 1 monotherapy biomarker data. As previously reported, all responding patients showed large increases in plasma interferon gamma (IFN-γ), a modulator of anti-tumor immunity, after 14 days of monotherapy with PLN-101095. Updated data show that blocking of αvβ8 by PLN-101095 also resulted in increases in CXCL9, a recruiter of T cells, and granzyme-B, a marker for cytotoxic arming in responding patients. Increased IFN-γ, CXCL9 and granzyme-B after PLN-101095 monotherapy signals a shift in the tumor microenvironment that could potentially resensitize tumors to pembrolizumab. Importantly, no non-responders experienced increases in these biomarkers.

Integrin-Targeted Delivery Platform

•Utilizing cell-specific integrin receptors, Pliant has developed a platform to deliver drug payloads, including siRNAs, to selective tissue types. Current programs are focused on delivering siRNAs to skeletal muscle cells and other tissues. Preclinical proof-of-concept studies are currently ongoing. The Company believes this integrin-targeting drug-delivery platform has the potential for broad applicability across multiple disease areas utilizing a variety of drug payloads. Pliant plans to provide additional detail on the platform and path forward, including initial treatment indications, in the second half of 2026.

Corporate Highlights

•Appointed Flavia Borellini, Ph.D. and Robert Iannone, M.D., M.S.C.E. to the Company’s Board of Directors. Dr. Borellini brings more than 25 years of executive management experience in the biopharmaceutical industry with a focus on the global development of targeted oncology drugs from preclinical to commercial stage. Dr. Iannone, who currently serves as Executive Vice President, Research and Development and Chief Medical Officer at Jazz Pharmaceuticals, brings more than two decades of executive drug development and regulatory leadership, including the approval of several targeted and immuno-oncology medicines.

Second Quarter 2026 Financial Results

•Research and development expenses were $16.7 million, as compared to $32.2 million for the prior-year quarter. The decrease was primarily due to completing close-out activities for BEACON-IPF, a Phase 2b/3 study of bexotegrast, in 2025 and reduced personnel-related expenses, including stock based compensation, driven by decreased headcount compared to

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Exhibit 99.1

Pliant Therapeutics Provides Corporate Update and Reports First Quarter 2026 Financial Results

First participant dosed in FORTIFY, a Phase 1b indication expansion trial of PLN-101095

Oral presentation at AACR 2026 featured updated data from Phase 1 trial of PLN-101095

showing deepening of confirmed responses in checkpoint inhibitor-refractory solid tumors

PLN-101095 spotlighted as novel IO approach as part of AACR's 2026 Highlights Plenary Session

SOUTH SAN FRANCISCO, CA., May 11, 2026 - Pliant Therapeutics, Inc. (Nasdaq: PLRX), a clinical-stage biotechnology company focused on the discovery and development of integrin-based therapeutics, today provided a corporate update and reported first quarter 2026 financial results.

“In the first quarter, our team showcased its clinical development capabilities, initiating FORTIFY, the Phase 1b trial of PLN-101095, ahead of schedule and dosing the first patient in April,” said Bernard Coulie, M.D., Ph.D., President and Chief Executive Officer of Pliant. “We were excited to highlight encouraging recent data from the Phase 1a trial of PLN-101095 at AACR showing deepening responses and increasing time on treatment. The team continues to make progress on pipeline programs emerging from Pliant's proprietary integrin platform while evaluating opportunities to expand our clinical-stage pipeline.”

Oncology Program

PLN-101095 is an oral, small molecule, dual selective inhibitor of αvβ8 and αvβ1 integrins designed to overcome checkpoint resistance by blocking TGF-β activation in the tumor microenvironment. Pliant is currently conducting a Phase 1a/1b open-label, dose-escalation and indication expansion trial (NCT0670706) to evaluate the safety, tolerability, pharmacokinetics, and preliminary evidence of antitumor activity of PLN-101095, as monotherapy and in combination with pembrolizumab, in patients with immune checkpoint inhibitor (ICI)-refractory advanced or metastatic solid tumors.

•FORTIFY, a Phase 1b indication expansion trial, enrolling and dosing patients. In April, the Company announced the dosing of its first participant in the FORTIFY Phase 1b indication expansion trial. The Phase 1b open-label, single dose trial will enroll three cohorts of patients including non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma and a subset of tumors with high tumor mutational burden. Tumor selection was based on data from the Phase 1 trial, as well as strong mechanistic rationale for integrin inhibition. 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.

•Oral presentation at AACR of updated Phase 1 data from PLN-101095 highlighted deepening of confirmed responses. In April, at the Clinical Trials Mini Symposium of the American Association for Cancer Research (AACR) 2026 Annual Meeting, the Company announced positive updated data from its Phase 1 trial of PLN-101095. Results showed that, in a heavily pretreated patient population, PLN-101095 demonstrated anti-tumor activity in combination with pembrolizumab, an FDA-approved ICI. 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. These clinical responses were observed in patients with cholangiocarcinoma, NSCLC, melanoma and head and neck squamous cell carcinoma, respectively. All responding patients showed large increases in plasma interferon gamma (IFN-γ) after 14 days of monotherapy with PLN-101095 prior to the addition of pembrolizumab. At Week 10, all responders maintained more than a 2-fold increase in IFN-γ. No non-responders showed meaningful increases in plasma IFN- γ. PLN-101095 was generally well tolerated across

all doses tested. IFN-γ is known to play a multifaceted role in modulating anti-tumor immunity, with increased tumor expression levels having previously been linked with better outcomes from immune checkpoint blockade. 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. Additionally, PLN-101095 was spotlighted as a novel immunotherapy approach as part of AACR’s 2026 Annual Meeting Highlights Plenary Session.

Integrin-Targeted Delivery Platform

•Utilizing cell-specific integrin receptors, Pliant has developed a platform to deliver drug payloads, including siRNAs, to selective tissue types. Current programs are focused on delivering siRNAs to skeletal muscle cells and other tissues. Preclinical proof-of-concept studies are currently ongoing. The Company believes this integrin-targeting drug-delivery platform has the potential for broad applicability across multiple disease ar