PLT012's CD36 Gambit: First-in-Class Novelty Meets Phase I Void in Crowded HCC

Pilatus Doses First Patient in Hong Kong for PLT012 HCC Trial

Pilatus Biosciences has dosed the first patient in Hong Kong for its ongoing Phase I clinical trial of PLT012, an investigational humanized monoclonal antibody targeting CD36, for advanced hepatocellular carcinoma (HCC), including patients with underlying liver dysfunction. The study, conducted by The Chinese University of Hong Kong, aims to collect biomarker data and assess early clinical activity to guide future development across chronic liver dysfunction and malignant disease. This follows an initial dosing in Houston, Texas, US, in March 2026, and the program has received FDA fast track designation.

• PLT012 is a humanized monoclonal antibody targeting cluster of differentiation 36 (CD36), which regulates lipid uptake in the tumor microenvironment. By blocking CD36, it aims to reduce immunosuppressive cells (regulatory T cells, pro-tumor macrophages) and restore cytotoxic CD8+ T cells and natural killer cell function. Preclinical testing demonstrated monotherapy activity in liver malignancy models with a favorable safety profile and sensitizing effects with other oncology treatments.
• The Phase I trial in Hong Kong, authorized by the Hong Kong Department of Health in July 2026, includes biomarker backfill and dose-expansion cohorts. It enrolls individuals with advanced HCC, including those with underlying liver dysfunction. The study's primary goal is to collect clinical and biomarker data to understand PLT012’s broader anti-tumor activity and inform its next stage of development for chronic liver dysfunction and malignant disease.
• The dosing in Hong Kong marks an expansion of Pilatus's global clinical development for PLT012, following the first patient dosing in Houston, Texas, US, in March 2026. The program has received FDA fast track designation, supporting its accelerated development. Pilatus, established in 2022, also launched a Hong Kong subsidiary earlier this year to leverage local research infrastructure and foster academic and strategic collaborations.

Addressing Unmet Needs in Advanced Hepatocellular Carcinoma

Despite meaningful advances in systemic therapy for hepatocellular carcinoma (HCC), significant clinical gaps persist across disease stages and patient subpopulations. The expanding use of first-line immune checkpoint inhibitor (ICI)-based combinations has created new sequencing challenges, while high-risk populations with vascular invasion and resistance to established agents remain inadequately served.

• Optimal second-line sequencing after first-line ICI-based therapy. A central unmet need is the absence of evidence-based guidance for patients progressing on first-line TKI plus PD-1 inhibitor combinations. A multicenter retrospective study of 288 unresectable HCC patients demonstrated that continuing immunotherapy in the second line confers no additional efficacy in this population — no significant differences were observed in PFS (9.2 vs. 6.3 months, p=0.062), OS (16.2 vs. 13.2 months, p=0.13), ORR (22.33% vs. 15.25%, p=0.276), or DCR (82.52% vs. 74.58%, p=0.227) — underscoring the need for alternative second-line strategies in this rapidly expanding cohort.

• Patients with portal vein tumor thrombosis (PVTT). HCC complicated by PVTT represents a high-risk population with poor outcomes on standard systemic therapy alone. Retrospective data show that concurrent radiation therapy added to immunotherapy yielded a median OS of only 7.7 months overall, improving to 10.2 months in Child-Turcotte-Pugh A patients, highlighting the need for more effective multimodal approaches. Emerging quadruple therapy combinations (HAIC-TACE with targeted therapy and immunotherapy) have reported objective response rates of approximately 82%, disease control rates of 97%, and PFS of 12.9 months, but prospective validation is lacking.

• Resistance to lenvatinib and other TKIs. Acquired resistance to lenvatinib remains a major barrier in advanced HCC. Nerve Growth Factor (NGF), secreted by HCC cells via a SRPK1-SRSF1 alternative splicing axis, has been identified as a mediator of resistance, activating the non-canonical MEK5-ERK5 pathway through TrkA. Elevated NGF expression was significantly associated with poor response to lenvatinib, shorter recurrence-free survival, and worse overall survival in independent patient cohorts, identifying a population in need of biomarker-guided combination strategies.

• Lack of validated predictive biomarkers for ICI-based regimens. The objective response rate for immune checkpoint inhibitors currently stands at only 30% to 40%, yet no practical biomarkers exist to predict therapeutic efficacy prior to treatment initiation. This gap limits patient selection and contributes to unnecessary toxicity exposure, representing a critical need for translational research integrating blood, tissue, and imaging-based biomarker discovery.

• Post-progression management after atezolizumab plus bevacizumab. Real-world data from 1,141 patients across 22 Asia-Pacific centers showed that only 55.1% of patients who discontinued first-line atezolizumab plus bevacizumab received subsequent treatment, with a median second-line PFS of just 2.9 months and OS of 8.0 months. The optimal second-line regimen in this setting remains undefined, with lenvatinib demonstrating longer OS than sorafenib (8.0 vs. 6.3 months) and TKI plus ICI combinations showing PFS of 5.4 months and OS of 12.6 months, but without prospective confirmation.

• HCC with macrovascular invasion beyond PVTT types I and II. Meta-analytic evidence across 33 studies and 10,551 patients supports surgical resection for HCC with type I/II portal vein tumor thrombosis or hepatic vein tumor thrombosis, but the optimal treatment strategy for other macrovascular invasion types remains unclear, representing an underserved population requiring dedicated prospective study.

PLT012's Novel CD36 Target in HCC Immunotherapy

Recent research has expanded the landscape of therapeutic targets in hepatocellular carcinoma (HCC) well beyond conventional pathways. At the cell surface, glypican-3 (GPC3) — a cell surface proteoglycan and oncofetal antigen — has been the subject of large-scale co-immunoprecipitation proteomic studies identifying 153 GPC3-associated proteins, among which Immunoglobulin Superfamily Member 1 (IGSF1), alpha-fetoprotein (AFP), FAT Atypical Cadherin 1 (FAT1), Formin 1 (FMN1), and Guanylate Cyclase 2C (GUCY2C) have been flagged as potential therapeutic targets. Separately, TRPM8, CD47, and CDK4 have been shown to be significantly overexpressed in HCC tumor tissue compared to adjacent non-tumorous liver (p < 0.001 for all three), with high expression correlating with poor prognostic criteria including high tumor grade, advanced stage, microvascular invasion, and necrosis; prolonged overall survival was significantly associated with low CDK4 expression (p = 0.019). FGFR4 has been validated as an oncogenic driver through the identification of acquired on-target kinase domain mutations — in the gatekeeper and hinge-1 residues — in patients treated with the selective FGFR4 inhibitor fisogatinib (BLU-554), confirming FGF19-FGFR4 pathway dependence in HCC.

Resistance mechanisms to multi-tyrosine kinase inhibitors (TKIs) have themselves revealed new targets. Caveolin-1 (CAV1) has been identified as a key driver of pan-TKI resistance, with CAV1 downregulation shown to induce apoptosis, inhibit metastasis, and restore TKI sensitivity in both inherent and acquired TKI-resistant HCC cells. Mechanistically, aberrant CAV1/STAT3/P70S6K signalling sustains survival, motility, and invasiveness in acquired TKI-resistant cells, and selective inhibition of AXL and FGFR4 downstream of the CAV1 pathway sensitized resistant cells to sorafenib and lenvatinib, respectively. MicroRNA-7-5p (miR-7) was identified as an endogenous regulator of CAV1, with its inhibitory effect on CAV1 and FGFR4 suppressing the STAT3/P70S6K pathway and triggering apoptosis in lenvatinib-resistant cells. Additionally, PLAGL2 overexpression has been shown to promote resistance to mitochondrial apoptosis through the C-MET/STAT3 signalling axis, with selenium sulfide (SeS₂) identified as a PLAGL2-targeted agent that suppresses C-MET/STAT3, AKT/mTOR, and MAPK signalling and triggers Bcl-2/Cyto C/Caspase-mediated intrinsic mitochondrial apoptosis in vitro and in vivo.

Within the immune microenvironment, STAT3 has emerged as a target capable of reshaping antitumor immunity: STAT3 inhibition induces immunogenic cell death (ICD) in HCC cells via calreticulin translocation to the cell surface and reduced expression of CD47, while also preventing expression of key glycolytic enzymes. STAT3 directly regulates transcription of CD47 and SLC2A1 (GLUT1), and the STAT3 inhibitor napabucasin reduced CD47 and GLUT1 expression while increasing tumor-infiltrated dendritic cells, macrophages, and CD4 and CD8 T cells in mouse models. Beyond STAT3, novel immune checkpoint targets under active investigation include LAG-3, TIM-3, TIGIT, and VISTA, alongside strategies to reprogram the fibrotic and immunosuppressive tumor microenvironment (TME). Epigenetic regulators, notably EZH2 and HDACs — with HDAC8 specifically shown to drive NAFLD-associated hepatocarcinogenesis through interaction with EZH2 to repress Wnt antagonists — as well as aberrant signalling cascades including Wnt/β-catenin, PI3K/AKT/mTOR, and RAS/RAF/MEK/ERK, and metabolic vulnerabilities, represent additional emerging target classes in HCC.

CD36 Inhibition: A Dual Strategy for HCC and Liver Dysfunction

The initiation of a Phase I clinical trial for PLT012, a novel anti-CD36 monoclonal antibody, represents a forward-looking strategy in the challenging landscape of hepatocellular carcinoma (HCC). This investigational therapy targets CD36, a protein increasingly recognized for its multifaceted role in both the metabolic drivers of liver disease and the progression of HCC. Research indicates that CD36 is a key player in lipid metabolism, with its upregulation linked to insulin resistance, metabolic dysfunction-associated steatotic liver disease (MASLD), and the subsequent development of HCC. By facilitating fatty acid uptake, CD36 contributes to hepatic steatosis and fibrosis, creating a fertile ground for tumor development.

Beyond its metabolic implications, studies also highlight CD36's critical involvement in shaping the tumor microenvironment. CD36+ cancer-associated fibroblasts (CAFs) have been shown to foster an immunosuppressive milieu in HCC, a malignancy notoriously resistant to immunotherapy. Intriguingly, evidence suggests that inhibiting CD36 can restore antitumor T-cell responses and synergize with anti-PD-1 therapies. This dual role positions PLT012 as a potentially transformative agent, capable of addressing both the metabolic underpinnings and the immune evasion mechanisms of HCC.

The inclusion of patients with underlying liver dysfunction in this trial is particularly significant, as this population often faces limited treatment options. Pilatus Biosciences' global development approach, coupled with FDA fast track designation, underscores the urgency and potential impact of this program. However, as with any early-stage asset, risks remain. The broad physiological expression of CD36 necessitates careful monitoring for potential off-target effects. While preclinical synergy with immunotherapies is promising, translating these findings into safe and effective clinical combinations will require rigorous validation. Nevertheless, PLT012's entry into the clinic signals a strategic move towards a novel, targeted approach that could redefine treatment paradigms for advanced HCC, especially for those with compromised liver health.