Silmitasertib

TAIPEI and SAN DIEGO, Aug. 12, 2026 /PRNewswire/ -- Senhwa Biosciences, Inc. (TPEx: 6492) today announced a significant research advance involving its investigational drug Pidnarulex (CX-5461). A multinational research team comprising investigators from Poland, Slovakia, France and Senhwa Biosciences in Taiwan found that, under specific cell-based experimental conditions, controlled light activation increased the cancer-cell-killing activity of CX-5461 by up to 96-fold and induced immunogenic cell death (ICD). The findings, published in the peer-reviewed journal Nucleic Acids Research, reveal that CX-5461 may have potential applications in photodynamic therapy and photoimmunotherapy in addition to its established research profile involving G-quadruplex (G4) targeting and DNA-damage-related mechanisms. The study opens a potential new development path for this clinical-stage asset. Turning Photosensitivity into a Controlled Therapeutic Mechanism Photosensitivity observed during the clinical development of CX-5461 has generally been viewed as a drug characteristic requiring risk management. In the new study, researchers reframed this property as a potentially controllable and spatially targeted therapeutic mechanism. By applying light of an appropriate wavelength to the tumor area, CX-5461 may be activated at the intended site, increasing local tumor-cell killing while limiting activity in non-illuminated tissue. This light-switch concept could extend CX-5461 from a systemically administered anticancer agent into a photosensitizer with temporal and spatial control. The approach may warrant further investigation in tumors that are accessible to external light, endoscopy or fiber-optic delivery, including selected skin, oral and esophageal tumors. Light Activation Triggers Tumor-Cell Killing and Immunogenic Cell Death The study further showed that light-activated CX-5461 not only directly damaged cancer cells but also induced ICD. When cancer cells die through an immunogenic process, they release or expose danger-associated signals, including cell-surface calreticulin, extracellular ATP and high-mobility group box 1 (HMGB1). These signals can help dendritic cells recognize and take up tumor antigens, potentially initiating a T-cell-mediated antitumor immune response. The therapeutic objective may therefore extend beyond destroying an illuminated local tumor. By making antigens from dying cancer cells more visible to the immune system, the treatment could provide a biological basis for using localized therapy to stimulate a broader antitumor immune response. Preclinical Findings Support an In Situ Cancer Vaccine Concept In preclinical mouse studies, animals whose tumors regressed after treatment with CX-5461 and light exposure showed suppressed tumor growth when subsequently challenged with the same cancer cells. The observation suggests that treatment may establish tumor-specific immune memory and supports further investigation of an in situ cancer vaccine concept. Under this approach, the patient's own tumor could serve as the source of tumor antigens, allowing an immune response to be initiated at the treatment site without the need to manufacture an external vaccine in advance. If validated through additional studies, this mechanism could also be explored in combination with immune checkpoint inhibitors targeting PD-1 or PD-L1, with the goal of broadening or prolonging antitumor immune activity. These findings are preclinical and require confirmation in additional animal studies and human clinical trials. Expanding the Potential Value of an Existing Clinical-Stage Asset In drug development, a molecule can gain a second life when its existing properties and mechanisms are understood in a new way. CX-5461 has already generated a body of development data across chemistry, manufacturing and controls, toxicology, pharmacology and human clinical safety. The new research reframes photosensitivity as a potentially useful therapeutic mechanism and extends the molecule's research potential beyond G4 targeting and DNA-damage response into photodynamic therapy, photoimmunotherapy and immune-combination strategies. Compared with developing an entirely new molecule from the outset, identifying a new mechanism and potential indications for an existing clinical-stage asset may support development continuity and broaden its potential product lifecycle, subject to successful preclinical, regulatory and clinical evaluation. Next Steps Senhwa views these findings as an important starting point for repositioning the value of CX-5461. Based on further validation, the Company plans to evaluate suitable tumor types, dosing and illumination conditions, light-delivery technologies and potential combination strategies. Senhwa will also seek multinational academic and industry collaborations to support the clinical translation of this photoimmunotherapy approach. Additional preclinical and regulatory work will be required before clinical development can proceed. The safety and efficacy of CX-5461 as a photodynamic or photoimmunotherapy treatment have not been established in human clinical trials, and CX-5461 has not been approved for commercial use in these applications. Please find more details via linkage below: About Senhwa Biosciences Senhwa Biosciences, Inc. is a Taiwan-based biotechnology company developing novel oncology therapeutics for cancers with significant unmet medical needs. Its pipeline includes CX-5461 and CX-4945, which are being evaluated in solid tumors and hematologic malignancies through international clinical and research collaborations. For more information, visit . SOURCE SENHWA BIOSCIENCES, INC. 21% more press release views with Request a Demo

TAIPEI, Aug. 6, 2026 /PRNewswire/ -- Senhwa Biosciences, Inc. (TPEx: 6492) today announced that the Taiwan Food and Drug Administration (TFDA) has cleared the Company's multicenter Phase 1b/2a clinical trial evaluating its investigational drug pidnarulex (CX-5461) in combination with a marketed PD-1 immune checkpoint inhibitor. The TFDA clearance follows clearance by the U.S. Food and Drug Administration (FDA) in June 2026, enabling the study to proceed in both Taiwan and the United States. This marks an important step in the development of CX-5461 from a DNA-targeting drug candidate into a potential immuno-oncology combination platform. The Phase 1b/2a study is designed to assess the safety, tolerability, and preliminary antitumor activity of the combination in patients with advanced solid tumors. The study will enroll patients with pancreatic cancer, colorectal cancer, and melanoma, including patients whose disease has developed resistance to prior immune checkpoint inhibitor therapy—settings in which effective treatment options remain limited. PD-1 and PD-L1 immune checkpoint inhibitors have transformed cancer care over the past decade. However, a substantial proportion of patients either do not respond initially or eventually develop resistance. In many so-called immune-cold tumors, limited immune-cell infiltration, insufficient antigen presentation, and an immunosuppressive tumor microenvironment can prevent the immune system from mounting an effective response, even when the PD-1 pathway is blocked. Overcoming these barriers and extending the reach of existing checkpoint therapies have therefore become central priorities in immuno-oncology research. Pidnarulex (CX-5461) is Senhwa's first-in-class investigational agent designed to induce DNA replication stress and DNA damage responses in cancer cells. Emerging research suggests that these mechanisms may not only directly impair tumor-cell survival but also promote immunogenic cell death, activate innate immune signaling, and increase immune activity within the tumor microenvironment. These potential effects provide the scientific rationale for evaluating whether CX-5461 can sensitize tumors to PD-1 blockade. The study will investigate whether CX-5461 can favorably alter the tumor immune microenvironment, increase immune-cell infiltration and antigen presentation, and make immune-cold tumors more recognizable and vulnerable to immune attack. In patients whose disease has become resistant to immune checkpoint inhibition, the study will also explore whether the combination can restore antitumor immune activity. These potential effects remain clinical hypotheses and have not yet been established in patients. The clinical program also reflects a broader shift across the biopharmaceutical industry. As immune checkpoint inhibitors become established backbones of cancer treatment, research and business development are increasingly focused on complementary agents that may broaden or deepen responses to existing PD-1 therapies, particularly in immune-cold and treatment-resistant tumors. Under Senhwa's collaboration model, a global pharmaceutical company is supplying the marketed PD-1 inhibitor, while Senhwa leads the global and regulatory activities for the study. Advancing a first-in-human combination study with a marketed immunotherapy, in collaboration with an experienced global pharmaceutical company, provides an internationally aligned framework for evaluating CX-5461 as a potential combination partner. Together with regulatory clearance in both the United States and Taiwan, the collaboration may increase the global visibility of CX-5461 and support future clinical development and partnering opportunities. The strategic significance of the trial extends beyond a single combination regimen. If clinical data support the safety, immune-sensitizing activity, and preliminary efficacy of CX-5461, the asset could potentially be evaluated with additional PD-1 or PD-L1 therapies, in other tumor types, and alongside modalities such as antibody-drug conjugates, radiotherapy, and photodynamic therapy. This could position CX-5461 as a platform asset with potential applications across multiple cancers, products, and treatment modalities. Senhwa will continue to advance study activation and patient enrollment and will use emerging safety, pharmacologic, efficacy, and biomarker data to identify the patient populations and development strategies most likely to benefit. The Company cautions that this is an early-stage clinical trial primarily intended to evaluate safety, tolerability, and preliminary efficacy. Whether CX-5461 can improve responses to PD-1 therapy, remodel the tumor immune microenvironment, or help overcome acquired resistance must be established through clinical data. About Senhwa Biosciences Senhwa Biosciences, Inc. is a Taiwan-based biotechnology company developing novel oncology therapeutics for cancers with significant unmet medical needs. Its pipeline includes CX-5461 and CX-4945, which are being evaluated in solid tumors and hematologic malignancies through international clinical and research collaborations. For more information, visit . SOURCE Senhwa Biosciences, Inc. 21% more press release views with Request a Demo