New Immunotherapy Shows Promise in Eliminating Aggressive Cancers

For over two decades, scientists have been investigating CD40 agonist antibodies as a potential cancer treatment. While early studies showed promise in activating the immune system to fight cancer cells, clinical trials yielded limited benefits and significant side effects. Now, a redesigned antibody, 2141-V11, is demonstrating remarkable results in early clinical trials, offering a potential breakthrough in cancer immunotherapy.

The Challenge with Early CD40 Agonist Antibodies

Initial CD40 agonist antibodies, while effective in animal models, faced challenges in human trials. Patients experienced severe side effects, including widespread inflammation, dangerously low platelet counts, and liver damage, even at low doses. These toxicities hindered the development of these therapies despite their potential.

A Redesigned Antibody: 2141-V11

In 2018, researchers at Rockefeller University, led by Jeffrey V. Ravetch, announced a potential solution. They engineered a new CD40 agonist antibody, 2141-V11, designed to improve effectiveness and reduce harmful side effects. The redesigned antibody binds tightly to human CD40 receptors and was modified to improve crosslinking by interacting with a specific Fc receptor. Laboratory studies showed the new design was about 10 times more effective at triggering an immune attack against tumors [1].

Phase 1 Clinical Trial Results: Tumor Shrinkage and Remission

Results from a phase 1 clinical trial, published in the journal Cancer Cell, showed significant tumor shrinkage in six of twelve participants with various metastatic cancers, including melanoma, renal cell carcinoma, and breast cancer. Notably, two patients experienced complete remission, meaning all detectable cancer disappeared [1].

“Seeing these significant shrinkages and even complete remission in such a small subset of patients is quite remarkable,” says Juan Osorio, a visiting assistant professor in Ravetch’s Leonard Wagner Laboratory of Molecular Genetics and Immunology and a medical oncologist at Memorial Sloan Kettering Cancer Center [1].

Systemic Response from Local Injection

A particularly unusual finding was the systemic response observed. Tumors located away from the injection site similarly shrank or were eliminated by immune cells. This effect, where local injection leads to a body-wide response, is uncommon in cancer treatments [1].

How CD40 Agonism Works

CD40 is a receptor found on immune cells, including B cells, macrophages, and dendritic cells. When activated by an agonist antibody, CD40 signals the immune system to mount a stronger response, triggering anti-tumor immunity and the generation of cancer-targeting T cells [1].

Targeted Delivery Minimizes Toxicity

Unlike traditional intravenous administration of CD40 therapies, 2141-V11 was injected directly into tumors. This targeted approach significantly reduced toxicity, as fewer healthy cells were exposed to the drug [1].

Immune Cells Transform the Tumor Environment

Analysis of treated tumors revealed a significant influx of immune cells, including dendritic cells, T cells, and B cells, forming structures resembling lymph nodes. These structures, known as tertiary lymphoid structures (TLS), are often associated with better outcomes in cancer treatment and stronger immunotherapy responses [1].

Ongoing and Future Clinical Trials

The promising results have spurred further clinical trials. Researchers are collaborating across institutions, including Memorial Sloan Kettering and Duke University, to evaluate 2141-V11 against difficult-to-treat cancers such as bladder cancer, prostate cancer, and glioblastoma. Nearly 200 patients are currently participating in phase 1 and phase 2 trials [1].

Researchers are also investigating why some patients respond to the treatment while others do not, focusing on factors like T cell clonality. Understanding these factors could help predict which patients will benefit from this therapy and potentially improve response rates.