What is DXd-ADC Technology?

Deruxtecan is a highly potent anticancer payload used in a new generation of antibody–drug conjugates (ADCs). Rather than being administered as a standalone chemotherapy, deruxtecan functions as the cytotoxic "engine" inside targeted biologic drugs designed to selectively attack cancer cells. These therapies are now changing the treatment landscape for multiple solid tumors, particularly those that have progressed despite prior standard treatments.

Understanding what deruxtecan is used for requires looking not only at the diseases it treats, but also at the technology platform behind it—DXd-ADC technology—developed by Daiichi Sankyo. This platform has been engineered to overcome key limitations observed in earlier ADC therapies, especially regarding safety, pharmacokinetics, and tumor penetration.

Deruxtecan as a Payload: How It Works

Deruxtecan (DXd) is a modified topoisomerase I inhibitor. Structurally related to SN-38, the active metabolite of irinotecan, it exhibits significantly enhanced cytotoxic potency—approximately ten times greater in preclinical comparisons. However, potency alone does not define its clinical value.

What makes deruxtecan particularly important in oncology is how it is delivered. In DXd-based ADCs, three components work together:

• A humanized monoclonal antibody that targets a specific tumor-associated antigen (such as HER2, TROP2, or HER3).
• The deruxtecan payload, responsible for inducing DNA damage in cancer cells by inhibiting topoisomerase I.
• A cleavable GGFG tetrapeptide linker that is stable in systemic circulation but selectively cleaved inside tumor cell lysosomes.

Once the antibody binds to its target antigen on the cancer cell surface, the ADC is internalized. Inside the lysosome, the linker is enzymatically cleaved, releasing active deruxtecan. The drug then interferes with DNA replication, leading to apoptosis of the tumor cell.

An important feature of deruxtecan is its extremely short half-life in systemic circulation once released. This rapid inactivation reduces exposure to healthy tissues, helping balance efficacy with safety.

Approved Uses of Deruxtecan-Based Drugs

Deruxtecan is used clinically as part of several ADC therapies, many of which have received regulatory approval across major oncology markets.

HER2-Positive Breast Cancer

Trastuzumab deruxtecan (T-DXd), marketed as Enhertu®, targets HER2-expressing tumors. It has been approved for:

• Unresectable or metastatic HER2-positive breast cancer after prior anti-HER2 therapy.
• HER2-low metastatic breast cancer, significantly expanding the population eligible for HER2-targeted therapy.
• Certain cases of metastatic triple-negative breast cancer (depending on HER2 expression status).

This has been especially meaningful for patients who previously experienced disease progression after trastuzumab or other HER2-targeted regimens.

Gastric and Gastroesophageal Cancer

Enhertu has also been approved for HER2-positive advanced gastric or gastroesophageal junction adenocarcinoma in patients previously treated with trastuzumab-based therapy. These cancers historically have limited targeted options after first-line failure, making deruxtecan-based therapy a clinically important development.

Non-Small Cell Lung Cancer (NSCLC)

Deruxtecan-based ADCs are being used and investigated in multiple NSCLC settings:

• HER2-mutant NSCLC (trastuzumab deruxtecan approved in certain regions).
• HER3-targeted deruxtecan ADCs (e.g., patritumab deruxtecan) in clinical development for EGFR-mutated NSCLC after TKI resistance.
• c-Met-targeted deruxtecan candidates in ongoing studies.

Given the molecular diversity of lung cancer, the flexibility of the DXd platform allows targeting multiple oncogenic drivers.

TROP2-Expressing Tumors

Datopotamab deruxtecan (Dato-DXd) targets TROP2, a surface protein highly expressed in several solid tumors. Clinical programs include:

• Metastatic triple-negative breast cancer (mTNBC).
• Hormone receptor–positive breast cancer.
• Non-small cell lung cancer.

TROP2 is broadly expressed, making it an attractive target for expanding deruxtecan-based therapy into wider patient populations.

Safety Considerations

Despite improvements in pharmacokinetic design, deruxtecan-based therapies are not without risks. Interstitial lung disease (ILD) has been observed in patients receiving certain DXd-based ADCs, requiring careful monitoring and early intervention.

As with many potent oncology drugs, balancing efficacy with toxicity remains a central clinical consideration. However, the short systemic half-life of released deruxtecan helps mitigate prolonged off-target exposure compared to earlier payload strategies. Ongoing clinical trials continue to refine dosing schedules, patient selection criteria, and combination regimens to optimize outcomes.

A Platform Technology, Not Just a Single Drug

Deruxtecan is best understood not as a standalone chemotherapy agent, but as a key component of a broader drug delivery platform. Its integration with:

• Stable, tumor-selective linkers
• High drug-to-antibody ratios
• Membrane-permeable cytotoxic design

The result is a class of therapies capable of addressing previously unmet needs in resistant or difficult-to-treat cancers.

FAQ

Dxd Antibodies

Dxd ELISA