Our Mission
Solving the Cytosolic Delivery Challenge
Xelcis Bio™ is a Boston-based preclinical oncology company built on a single conviction: cytosolic delivery is a defining bottleneck limiting the clinical potential of many of today's most promising cancer therapeutics.
We are developing TRIDENT™ — a biocompatible nanoparticle platform designed to enable cytosolic access across targeted protein degraders, biologics, RNA therapeutics, and targeted chemotherapy.
Our approach builds on a decade of clinical and translational experience with the iron oxide nanoparticle delivery class, including Phase 1 clinical experience with the predecessor platform in oncology patients.
Proven Platform Lineage
Built on a predecessor iron oxide nanoparticle platform with Phase 1 clinical experience in 15 patients and no dose-limiting toxicities observed.
Preclinical Evidence
TDOX (TRIDENT™ Doxorubicin) has demonstrated strong in vitro activity in 3D spheroid multidrug-resistant models. In parallel, feasibility studies with model protein cargoes and dual-loading experiments have shown that TRIDENT™ can support co-delivery of protein and small-molecule therapeutics within a single nanoparticle.
Multi-Modality Platform
Modular surface chemistry enables application across diverse therapeutic classes without redesign of the core platform.
The Challenge
Cytosolic Access Is the Last-Mile Problem in Oncology Drug Delivery
Many promising cancer therapeutics underperform not because of weak biology, but because they cannot efficiently reach their intracellular site of action. After systemic administration and cellular uptake, payloads are routinely sequestered in endosomes, never reaching the cytosol where targets reside.
This is not a niche problem. It limits the potential of PROTACs, molecular glues, RNA therapeutics, intracellular biologics, and chemotherapy in multidrug-resistant tumors. Solving cytosolic delivery can expand the value of each of these modalities.
The Endosomal Trap
The majority of endocytosed payload is recycled or degraded before cytosolic escape occurs — the central efficiency barrier for every modality requiring intracellular access.
Dose Compression
Inefficient cytosolic delivery forces higher systemic dosing — narrowing therapeutic windows and driving off-target toxicity across programs.
A Universal Limitation
PROTACs, siRNA, nanobodies, and chemotherapy all face the same last-mile barrier. Solving it once creates value across all modalities.
The TRIDENT™ Platform
Engineered for Cytosolic Delivery — Across Modalities
TRIDENT™ is a pH-responsive biocompatible nanoparticle platform designed to enable cytosolic delivery. By combining cellular uptake, endosomal escape, and glutathione-triggered payload release through Z-Link™ surface chemistry, TRIDENT™ is designed to address the key steps required for cytosolic delivery.
Unlike approaches that depend on receptor expression or lysosomal processing, TRIDENT™ is designed for broader applicability across payload classes. Payload release is designed to occur in response to cytosolic glutathione.
Enhanced Cellular Uptake
Receptor-independent uptake improves intracellular accumulation versus free payload, increasing the amount of therapeutic available at the site of action.
Endosomal Escape
pH-responsive chemistry enables release from endosomal compartments, allowing payloads to access the cytosol before degradation.
Cytosolic Release
Z-Link™ disulfide chemistry is designed to trigger payload release in response to cytosolic glutathione, helping release occur where intracellular activity is needed.
Modality Coverage
One Platform. Multiple Therapeutic Classes.
TRIDENT™ is being developed as an enabling delivery solution for therapeutic modalities where cytosolic access is a limiting factor. Its modular surface chemistry is designed to support diverse payload formats without redesign of the core platform.
Targeted Protein Degradation
PROTACs and molecular glues require cytosolic access to engage E3 ligases and drive target degradation. TRIDENT™ is designed to deliver these bifunctional molecules beyond the endosomal barrier.
Nanobodies and Biologics
Biologics with intracellular targets require cytosolic access for functional activity. TRIDENT™ is designed to improve intracellular delivery of these payloads beyond endosomal confinement.
Targeted Chemotherapy
TDOX demonstrates that TRIDENT™ can overcome multidrug resistance by improving intracellular concentration at the site of action while reducing systemic exposure.
RNA Therapeutics
Endosomal entrapment remains a major barrier for siRNA, ASO, and mRNA delivery. TRIDENT™ is designed to support intracellular delivery of nucleic acid payloads, informed by the Xelcis Bio™ team's prior experience advancing iron oxide nanoparticle-based RNA delivery in oncology.
Partnership
Partnering to Rescue Delivery-Limited Assets
Xelcis Bio™ is engaging pharmaceutical and biotech partners to evaluate TRIDENT™ for assets where intracellular delivery is a development barrier.
8-Week PROTAC Demonstration Program
Generate early proof-of-concept data with your payload on TRIDENT™ through a time-defined engagement model designed to reduce partner risk.
If your pipeline includes assets limited by intracellular delivery, we welcome a discussion.
Leadership
Led by a Team That Has Done This Before
Xelcis Bio™ was founded by R. Michael Dudley (CEO) and Dr. Peter Liu (CSO), who previously co-developed and advanced an antisense RNA therapeutic into clinical-stage development at TransCode Therapeutics (NASDAQ: RNAZ). The leadership and advisory team bring expertise in oncology drug delivery, clinical development, regulatory strategy, and biotech financing.
R. Michael Dudley
CEO & Co-Founder
Former Co-Founder and CEO of TransCode Therapeutics (NASDAQ: RNAZ). Raised $60M+ in public and private capital.
Rick Clemon, CPA, CGMA
Chief Financial Advisor
Financial strategy and capital markets for biotech and life sciences.
Dr. Peter Liu
CSO & Co-Founder
Lead scientist on the predecessor platform and architect of the TRIDENT™ delivery platform.
Dr. Allan Green & Dr. Lee Simon
Regulatory Consultants — SDG LLC
FDA regulatory strategy and IND advisory for novel drug delivery systems.
Dr. Candida Fratazzi
Chief Medical Advisor
Oncology clinical development, IND strategy, and trial design.
The TRIDENT™ therapeutic delivery platform and all associated therapeutic candidates — including TDOX (TRIDENT™ Doxorubicin), TRIDENT™-PROTAC, TRIDENT™ Nucleic Acid, and TRIDENT™ Nanobody/NDC — are investigational products currently in preclinical development. None of these products have been approved by the U.S. Food and Drug Administration (FDA) or any other regulatory agency for safety, efficacy, or any therapeutic use. Clinical validation data referenced relate to prior nanoparticle delivery work advanced at TransCode Therapeutics and are included to demonstrate the scientific lineage and development experience that informed Xelcis Bio's proprietary TRIDENT™ platform. These clinical studies were not conducted by Xelcis Bio™ and do not represent clinical studies of TRIDENT™.
Our Track Record
A Platform Built on Clinical Lineage
TRIDENT™ was developed by Xelcis Bio™ based on scientific and translational experience gained from prior clinical work with the iron oxide nanoparticle delivery class in oncology. Earlier work by the founding team supported advancement of an antisense RNA candidate through Phase 1 in oncology patients and later FDA acceptance of a Phase 2a IND in February 2026. The Xelcis Bio™ team has translated those learnings into TRIDENT™ — a proprietary, CMC-aligned platform purpose-built for next-generation oncology modalities.
The Xelcis founding team took a predecessor company public on NASDAQ, raised over $60M, and advanced a nucleic acid therapeutic through clinical-stage development on this platform class. TRIDENT™ improves on that foundation with defined, CMC-aligned chemistry — purpose-built for next-generation oncology modalities.
9.5×
Greater cytotoxic activity vs. Doxil®
(3D spheroid MDR model)
90%
Tumor growth inhibition
(in vitro MDR model)
14×
Greater cellular uptake vs. Doxil®
(MDR resistant cells)
Data generated in vitro in 3D spheroid multidrug-resistant cancer cell models. Results are preclinical and may not predict clinical outcomes.