The Next Leap in Personalized Cancer Care

In my last article we talked about the relevance of performing Tumor Molecular profiles for cancer patients as a way to provide wider access to personalized medicine, and we highlighted some forms of targeted treatments. 

Today, we’ll cover one of the first targeted treatments: monoclonal antibodies and what’s coming in this type of treatment.

Cancer care has never been more dynamic. We are at an inflection point where the precision of tumor molecular profiling (TMP) and the ingenuity of targeted therapy are converging to shape the future of oncology. One of the innovations at the forefront of this transformation is a class of treatments that promises to redefine how we approach cancer: Antibody-Drug Conjugates (ADCs). But what are they and how did we get here?

Monoclonal Antibodies: The First Precision Strike in Cancer Therapy

For decades, chemotherapy was one of the few weapons against cancer — a blunt force attack that harmed healthy cells almost as much as cancerous ones. The introduction of monoclonal antibodies (mAbs) in the late 20th century was a revolution in itself.

Imagine the immune system as a security force searching for criminals. Traditional chemotherapy indiscriminately attacks all cells, much like an unchecked bombing campaign. But monoclonal antibodies? They act like precision-guided drones, recognizing and locking onto specific molecular targets on cancer cells, leaving healthy tissues largely unscathed.

They work like a key and lock, they only can open or close a lock that they were specifically designed for. 

This means that if a cancer cell has a specific mutation (lock) for which we have an mAb (key), we can target those cells and lock their malignancy by blocking the activity that such mutation, or lock, gave the tumor.

One of the first mAb breakthroughs was rituximab (Rituxan), a drug that transformed the treatment of non-Hodgkin’s lymphoma and chronic lymphocytic leukemia. By targeting CD20, a protein found on B-cell lymphomas, Rituxan marked the dawn of an era where cancer drugs could selectively attack tumors.

Then came trastuzumab (Herceptin), a game-changer for HER2-positive breast cancer. Before Herceptin, HER2-positive breast cancer was a death sentence for many women. But by specifically binding to the HER2 receptor, trastuzumab inhibited the aggressive signaling pathway that fueled tumor growth, improving survival rates dramatically.

Other blockbuster monoclonal antibodies followed:

• Bevacizumab (Avastin): Targets VEGF, starving tumors by cutting off their blood supply. Used in colorectal, lung, and ovarian cancer.

• Pembrolizumab (Keytruda)  and Nivolumab (Opdivo): Checkpoint inhibitors that block PD-1, helping the immune system recognize and attack tumors. Approved for melanoma, lung, bladder, and many other cancers.

• Cetuximab (Erbitux): Targets EGFR, used in colorectal and head and neck cancers.

Yet, one of the remaining issues of mAbs is that cancer cells are similar to a stained glass, formed by many pieces of glass that differ in size, color, space, which means that not all cancer cells (stained glasses) share the same features and, therefore, the mAbs can only target those that express the mutation (lock) for which their key was designed. 

This explains why some cancer patients that undergo treatment with mAbs respond well in the beginning of the treatment but can later present resistance, as the tumor biology changes and acquires new molecular and genomic alterations. 

From Lock-and-Key to Supercharged Precision Weapons: The Rise of ADCs

Monoclonal antibodies were a breakthrough, but they had their limits. While they could block growth signals or tag cancer cells for immune destruction, they didn’t always kill the tumor outright. This is where ADCs elevate the game.

Imagine you’re a surgeon. Traditional mAbs are like scalpels, precise but limited in power. ADCs, on the other hand, are like scalpels embedded with explosives: they retain precision but now pack a devastating punch.

ADCs take the monoclonal antibody framework and attach a chemotherapy molecule to it, ensuring that highly potent cancer-killing drugs are delivered only to tumor cells. This means:

1. Precision Targeting: The monoclonal antibody component binds to a specific tumor antigen, ensuring the drug is delivered only where it’s needed.

2. Potent Payloads: Once inside the cancer cell, the ADC releases a chemotherapy-like drug, delivering 100 to 1,000 times the potency of conventional chemo, but with far fewer systemic effects.

3. Reduced Toxicity: Traditional chemotherapy affects both cancerous and healthy cells, leading to significant side effects. ADCs dramatically reduce collateral damage, making treatment more tolerable and effective.

Why ADCs Are the Next Step in Personalized Cancer Care

The future of precision oncology is not just about blocking cancer growth, it’s about obliterating tumors with extreme specificity. ADCs represent the perfect marriage of targeted therapy and systemic therapy (such as chemotherapy), an approach that aligns seamlessly with the advancements in genomic medicine.

We can now use next-generation sequencing (NGS) and get the specific Tumor Molecular Profile (TMP) of a cancer and implement biomarker-driven strategies to determine which patients express the right molecular targets for ADC therapy. 

This eliminates the trial-and-error approach of traditional treatment paradigms, ensuring that every patient receives the most effective therapy tailored to their tumor’s unique genetic signature.

Big Pharma’s Billion-Dollar Bet: The ADC Arms Race

These aren’t simply incremental improvements – ADCs represent a quantum leap from traditional monoclonal antibodies (mAbs), delivering chemotherapy-like potency with unprecedented precision. 

The pharmaceutical industry has taken notice — and they’re all in. In the last five years, ADC-focused biotech deals have surged, with major players investing heavily:

• Pfizer’s US$43 billion acquisition of Seagen (a pioneer in ADC development) underscores the strategic importance of these therapies.

• Daiichi Sankyo and AstraZeneca’s Enhertu (trastuzumab deruxtecan) has shattered expectations, proving ADCs can outperform standard treatments in breast cancer and beyond.

• Gilead’s US$21 billion purchase of Immunomedics brought Trodelvy (sacituzumab govitecan), an ADC now setting new standards in triple-negative breast cancer.

• Merck, Roche, and AbbVie are aggressively expanding their ADC pipelines, betting that this is the future of oncology.

Beyond Oncology: Expanding the ADC Horizon

While ADCs are revolutionizing breast, lung, and hematologic cancers, their impact will soon extend far beyond. New-generation ADCs are being designed to tackle:

• Gastrointestinal cancers (colorectal, gastric, pancreatic)

• Brain tumors (glioblastomas, medulloblastomas)

• Hard-to-treat solid tumors with limited treatment options

Yet, ADCs, while specific and potent, still face the challenge of not being able to eliminate all cancer cells. 

Yes, they are able to insert the chemotherapy molecule into specific cancer cells that hold a specific mutation, but a tumor is built by multiple types of cells, each one with its own molecular profile (aka, intratumor heterogeneity), which explains part of the complexity of cancer treatment.

The next frontier? Combining ADCs with immunotherapy, oncolytic viruses, and even gene-editing technologies like CRISPR, a strategy that could redefine what’s possible in cancer treatment and ensure elimination of most, if not all, cancer cells.

Mexico: The Time to Embrace ADCs Is Now

As Latin America grapples with rising cancer incidence and inconsistent access to precision medicine, ADCs offer another opportunity to bridge the gap. If Mexico wants to lead in next-generation cancer care, we must:

1. Accelerate the adoption of tumor molecular profiling (TMP) to match the right ADCs with the right patients.

2. Push for regulatory approval and reimbursement policies that make these life-saving therapies accessible.

3. Integrate ADCs into national treatment guidelines, ensuring they are not just an option for the privileged few but a standard for all.

The challenge is clear, but so is the opportunity. The next wave of oncology isn’t coming, it’s already here. The only question is whether we’re ready to ride it or risk being left behind.

In my next article we’ll cover one of the other great innovations at the forefront of cancer care:  Chimeric antigen T-cell (CAR-T) therapy.

Stay tuned and reveal the power of your genome!