Cancer drug resistance is a significant challenge in oncology. It is characterised by the ability of cancer cells to survive and proliferate despite treatment, often due to genetic, epigenetic, and microenvironmental factors.
To discover what can be done to develop innovative therapies to reverse cancer drug resistance, Digital Journal spoke with Dr. John Yu, CEO of Kairos Pharma, a clinical-stage biopharmaceutical company.
Digital Journal: Can you provide a brief background on Kairos Pharma and your role with the company?
Dr. John Yu: I’m a neurosurgeon by training, with a deep academic and clinical focus on brain tumors and immunotherapy. Over the last 25 years, my research has centered on how the immune system can be leveraged to fight cancer, especially in cases where standard treatments fail. That passion ultimately led to the founding of Kairos Pharma.
Kairos Pharma is a clinical-stage company developing targeted therapeutics and immunotherapies to combat cancer drug resistance, a fundamental barrier to curing solid tumors. Our goal is to intervene early in the resistance process and re-sensitize cancer cells to therapy, all while supporting the immune system’s ability to detect and destroy malignant cells.
We’re currently advancing a pipeline of therapies designed to inhibit molecular drivers of resistance, such as the protein CD-105, which we’ve identified as a key player in the transition of tumors into treatment-resistant states. Our team includes world-class researchers, clinicians, and drug developers who are committed to turning cancer drug resistance into a manageable, and potentially reversible challenge.
DJ: What is cancer drug resistance, and how do conventional treatments address it today?
Yu: Cancer drug resistance is one of the greatest obstacles in oncology. Even when therapy is initially effective, many tumors evolve over time to become unresponsive to it. This can happen through a variety of mechanisms, changes in gene expression, mutations in drug targets, immune evasion, or transformation into more aggressive, stem-like phenotypes.
One of the most important aspects we’ve uncovered is the role of CD-105, a protein that becomes elevated after cancer treatment. Its expression correlates with a shift in the tumor cell population toward cancer stem-like cells, a subset of cells that are more adaptable, resistant to stress, and difficult to eliminate. These cells have enhanced survival mechanisms and are often the culprits behind a cancer’s resistance to the medication that is being used to target it.
Conventional treatment regimens try to stay ahead of resistance by switching drugs or using combination therapies. But these approaches are often reactive, not preventive. Our strategy is to directly disrupt the biological switch that enables resistance, so that treatments remain effective longer, and relapses are fewer and less aggressive.
DJ: How do Kairos’ therapies uniquely overcome this resistance?
Yu: Our lead approach involves developing an antibody therapy that specifically targets CD-105. By using our therapy to bind to this protein, we can block the signaling cascade that leads to the stem-like transformation of cancer cells. This not only stops resistance from progressing but also promotes a return to a more differentiated, treatment-sensitive state.
In preclinical models, we’ve seen that inhibiting CD-105 restores responsiveness to a variety of drugs, including chemotherapy and checkpoint inhibitors. Importantly, our antibody doesn’t act like a traditional cytotoxic agent, it modifies the tumor environment in a way that re-sensitizes it to existing therapies.
What makes our approach unique is that we are not trying to replace the standard of care. Instead, we’re amplifying its effect. By reversing the cellular and molecular changes that lead to resistance, our therapies may allow clinicians to get better results with the tools they already have and give patients a longer window of effective treatment.
DJ: Which cancer types are you currently focused on, and why?
Yu: Our initial focus is on prostate cancer and non-small cell lung cancer, two of the most diagnosed cancers worldwide, and both face major challenges with treatment resistance. These indications were chosen based on our internal research and the clinical expertise of our team.
For example, Dr. Neil Bhowmick, our Chief Scientific Officer, is a recognized leader in prostate cancer biology, and his insights have guided our translational strategy. In lung cancer, resistance to targeted therapies and immunotherapies is a well-documented issue, particularly after first or second-line treatment.
That said, the CD-105 resistance mechanism is not limited to one tumor type. In our preclinical and early clinical work, we’ve observed CD-105 overexpression in breast cancer, colon cancer, and head and neck squamous cell carcinoma. That suggests our approach may be broadly applicable, and we fully intend to expand into these indications as the data supports it.
Our vision is to build a platform that can impact a wide array of cancers, starting with those where the unmet need is most urgent.
DJ: What are the biggest challenges in bringing these therapies through regulatory approval?
Yu: Drug development always comes with hurdles, and oncology is particularly complex. From a regulatory standpoint, we need to show that our therapies are safe, well-tolerated, and deliver a meaningful clinical benefit. That means running rigorous trials with clear endpoints, such as progression-free survival, overall survival, or response rate improvements when our drug is added to standard therapy.
One specific challenge we face is that drug resistance is often a secondary endpoint in oncology trials. It’s not always as easy to quantify as tumor shrinkage or biomarker changes. That’s why we’re designing our studies to demonstrate that our therapy can delay resistance, extend the durability of response, and ultimately improve outcomes over time.
We’re encouraged by the growing openness of regulators, including the FDA, to innovative mechanisms that address resistance and immune suppression. If we can back our claims with data, we believe there will be a clear path forward.
DJ: What’s next for Kairos over the next 3–5 years?
Yu: In the near term, we’re moving from preclinical and early safety studies into Phase 1/2 clinical trials, with a focus on prostate and lung cancers. We also have plans to publish additional preclinical findings and present them at major oncology conferences to continue building awareness among clinicians and researchers.
Longer term, we expect to expand into multiple tumor types, explore combination regimens with checkpoint inhibitors and chemotherapy, and pursue strategic partnerships to accelerate development and commercialization. We’re also actively engaging in the investment and biotech community to build the infrastructure needed for late-stage trials and eventual market entry.
Our goal is to position Kairos as a leader in the fight against cancer drug resistance, not just with one drug, but with a new therapeutic category that changes how we think about treatment failure in cancer.
