Our science
Clinical landscape
Immune checkpoint inhibitors, cell therapies, and antibody drug conjugates have advanced cancer care, but each presents limitations in efficacy, safety, and/or accessibility. T-cell activation requires two distinct signals: T-cell receptor engagement (Signal 1) and co-stimulation through receptors like CD28 or CD137 (Signal 2). While CD3 T-cell engagers alone have proven effective in treating blood cancers, overcoming the immunosuppressive environment of solid tumors requires both signals.
Targeted Modalities
Efficacy
Safety
Challenge
Checkpoint Inhibitors
30% response rate,
heme & Solid
Autoimmune & inflammatory toxicity
Low Response Rate
CAR-T Cell Therapy
80% Response Rate,
Heme only
CRS & On-target, off-tumor Toxicity
Limited Patient Access
ADCs
30-40% Response Rate, Heme & Solid
Toxicity related to payload toxin
Sub-Optimal Efficacy at Low Tumor antigen Densities, Dose limiting Toxicities
CD3 T-Cell Engagers
60-80% Response Rate,
Heme only
CRS & on-target, off-tumor toxicity
low Response Rate
in Solid tumors
Swipe to Explore
T-cells in immune-primed tumors
have activated signal 1
Strategy - Boost signal 2 with
CD28 bispecific antibody (+/- SoC)
T-cells in immune-cold tumors
lack signals 1 & 2
Strategy - Deliver both signals 1 and 2 with
CD28 and CD3 bispecific combinations
Our approach
Rondo’s approach leverages CD28 as a co-stimulation to enhance and sustain T-cell activity in solid tumors. By pairing CD28 with CD3or tumor-targeting arms, such as Nectin-4, and other proprietary targets, we create bispecific antibodies that drive potent, localized immune activation while minimizing systemic toxicity.
This modular design enables tailored immune engagement across multiple tumor types and treatment settings. Unlike prior CD28super-agonists that triggered broad immune activation, Rondo’s bispecifics restrict co-stimulation to the tumor microenvironment to achieve deeper, more durable responses safely.
CD28 provides a powerful and versatile co-stimulatory signal, sustaining T-cell proliferation and persistence even in tumors with low antigen expression – unlocking the potential of immune engagement across a wide range of solid cancers.
Our Strategic advantage
Maintaining efficacy while reducing toxicity is Rondo Therapeutics’ strategy, providing clinicians flexibility with dosing strategies and combination regimens.
Immune cell-engaging mechanism of action
Sustained T-cell mediated tumor cell killing
Maximum therapeutic window
Development
NGS-based discovery enables rapid characterization and development of highly-diverse binding arm collections which are critical for high-throughput lead optimization.
Using a common-light chain format enables flexible pairing of immune effector and tumor targeting arms.
Our proprietary high-throughput functional and biophysical assays optimize for desired properties and rapidly identify the best bispecific antibody development candidates.
