Mobilizing the Immune System Against Solid Tumors

Progress in medicine often begins with a quiet milestone: the first patient receiving a new experimental therapy.

Canaan company Rondo Therapeutics has reached that point, with the first patient dosed in a Phase 1/1b clinical trial evaluating RNDO-564, a novel antibody designed to help the immune system recognize and attack cancer. The study will evaluate the therapy in patients with advanced bladder cancer and other solid tumors that express a protein called Nectin-4.

Moving from laboratory research into a human clinical trial is a critical step in determining whether a new scientific approach can ultimately become a treatment.

Treating solid tumors remains one of the biggest challenges in cancer medicine.

Some recent therapies have improved outcomes for patients with bladder cancer and other tumors that express Nectin-4. But many patients eventually see their disease progress, and some treatments can cause side effects that limit how long patients are able to stay on therapy.

Rondo’s approach is designed to address those challenges by more precisely activating the immune system at the tumor site.

Instead of delivering chemotherapy directly to cancer cells, RNDO-564 aims to help the body’s own immune cells do the work.

RNDO-564 is a type of engineered antibody called a bispecific antibody.

Antibodies are proteins that can recognize and bind to specific targets in the body. A bispecific antibody is designed to bind to two targets simultaneously.

In this case, RNDO-564 connects:

• Nectin-4, a protein found on certain tumor cells
• CD28, a receptor on immune cells called T cells

By linking these two targets, RNDO-564 is designed to activate T cells directly at the tumor site. The goal is to stimulate a stronger immune attack against cancer while limiting immune activation elsewhere in the body.

According to Rondo, the antibody has been engineered to deliver this immune stimulation in a way that focuses activity within the tumor environment.

The Phase 1/1b trial is a first-in-human study, meaning it is the first time RNDO-564 is being tested in patients.

Researchers will evaluate:

• Safety and tolerability
• How the drug behaves in the body
• Early signs of anti-tumor activity

The therapy will be studied both alone and in combination with the immunotherapy drug pembrolizumab. Early-stage clinical trials are designed primarily to determine whether a new therapy can be given safely and whether it behaves as expected based on laboratory research.

In preclinical studies, Rondo reports that RNDO-564 demonstrated several promising characteristics, including:

• activating immune cells to kill Nectin-4–expressing tumor cells
  • inhibiting tumor growth in animal models
  • maintaining activity against tumor cells that had become resistant to certain existing therapies

These findings provided the scientific rationale for advancing the program into human clinical trials.

Rondo’s broader platform focuses on developing immune-cell-engaging bispecific antibodies designed to stimulate T cells within the tumor environment.

The start of the RNDO-564 clinical trial marks an important step in testing that approach in patients.

Drug development is a long process, and early trials represent only the beginning. But every potential new therapy starts here—with the first patient, and the first opportunity to translate scientific insight into clinical impact.