Antibody-Drug Conjugates (ADCs) Explained: How Smart Bombs Work by Cancer Type

Antibody-drug conjugates (ADCs) are a class of targeted cancer medicines designed to deliver a potent anticancer drug to cells carrying a particular molecular target. They are often described as “smart bombs” because they combine an antibody that recognizes a target with a drug payload intended to kill the cancer cell.

ADCs have changed treatment options for several cancers, including breast cancer, bladder cancer, ovarian cancer, cervical cancer, lung cancer and certain blood cancers. Their usefulness, however, depends on the specific drug, cancer subtype, treatment setting, previous therapies and, in some cases, biomarker test results.

This guide explains the technology in plain English and maps important ADCs to the cancer types for which they have established uses. It focuses on the U.S. Food and Drug Administration (FDA) regulatory framework as of October 16, 2026; availability and approved indications may differ in other countries.

Key takeaway: An ADC is not automatically suitable for every patient with a particular cancer. The correct question is not simply “Is there an ADC for this cancer?” but “Is this specific ADC appropriate for this tumour subtype, biomarker profile, disease stage and treatment history?”

1. What Is an Antibody-Drug Conjugate?

An antibody-drug conjugate is a medicine made by chemically attaching a drug to a monoclonal antibody. The antibody recognizes a particular protein or other molecular target, while the attached payload delivers an anticancer effect.

The National Cancer Institute provides a basic definition in its antibody-drug conjugate reference.

Most ADCs contain three major components:

1. Antibody

Recognizes a selected molecular target on or associated with a cancer cell.

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2. Linker

Connects the antibody to the drug payload and influences when the payload is released.

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3. Drug payload

Damages essential cellular structures or processes, causing cancer-cell death.

Some ADCs use payloads that interfere with microtubules, structures needed for cell division. Others use topoisomerase inhibitors that interfere with DNA replication or agents that damage DNA.

How does an ADC work?

1. Recognition: The antibody binds to its molecular target on the cancer cell.
2. Cell entry: In many ADCs, the antibody-target complex is taken into the cell.
3. Payload release: The linker is processed or broken down, allowing the active drug to become available.
4. Cell damage: The payload disrupts a critical cellular process, potentially causing cancer-cell death.
5. Possible bystander effect: Some released payload can reach nearby cells, including cancer cells with lower target expression. This effect depends on the ADC's design and the tumour environment.

Not all ADCs behave identically. Their internalization, linker stability, payload release and effects on surrounding cells depend on their individual design.

2. Why Are ADCs Called “Smart Bombs”?

The phrase captures the concept of targeted delivery, but it can create unrealistic expectations if taken literally.

Traditional chemotherapy may circulate throughout the body and affect both cancer cells and healthy cells that divide rapidly. An ADC attempts to concentrate the effect of a potent drug in cells associated with a selected target.

However, an ADC is not a perfectly guided missile. Several factors limit its selectivity:

• The target may also be present on some healthy cells.
• Different cancer cells within the same tumour may express different amounts of the target.
• The antibody may not reach every part of a solid tumour equally well.
• Some payload may be released before reaching the intended cell.
• The drug payload can affect normal tissues even when the antibody has useful target selectivity.
• Cancer cells may become resistant by reducing target expression or changing how the drug enters or responds within the cell.

Important distinction: Targeted delivery does not mean zero toxicity. ADCs can cause serious adverse effects, including low blood-cell counts, nerve damage, eye problems, severe skin reactions and inflammation of the lungs. The risks depend on the individual product.

3. ADCs vs Conventional Chemotherapy, Immunotherapy and Radioligand Therapy

Treatment	How it works	Important distinction
Conventional chemotherapy	Uses drugs that damage or disrupt processes required for cell growth and survival.	Often affects healthy rapidly dividing cells as well as cancer cells.
Antibody-drug conjugate	Uses an antibody to recognize a target and deliver a linked cytotoxic payload.	Combines antibody-based targeting with a potent drug payload.
Immune checkpoint inhibitor	Blocks immune-regulatory pathways, such as PD-1 or PD-L1, to help immune cells attack cancer.	Does not ordinarily deliver a cytotoxic payload attached to an antibody.
Unconjugated monoclonal antibody	Binds a molecular target and may block signals, recruit immune activity or produce another biological effect.	Does not have the same linked cytotoxic payload architecture as an ADC.
Radioligand therapy	Uses a targeting molecule linked to a radioactive payload to deliver radiation to target-expressing cells.	Examples include lutetium-177 PSMA and lutetium-177 DOTATATE therapies. These are not ADCs.
CAR T-cell therapy	Uses genetically modified immune cells to recognize and attack cancer cells.	It is a cell therapy, not an antibody-linked chemotherapy delivery system.

ADCs are sometimes combined with immune checkpoint inhibitors or other medicines. In these regimens, each drug has a distinct role, and the benefits and risks of the combination must be evaluated as a whole.

For a related explanation of targeted radiation, see the separate guide to radioligand therapy, including Lu-177 PSMA and Lu-177 DOTATATE.

4. ADCs by Cancer Type: Which Medicines Are Used?

The following is a selected guide to important ADCs with FDA-approved indications, not a complete worldwide prescribing catalogue. Approval in one cancer does not automatically establish a role in another cancer expressing the same target.

Cancer type	Example ADC	Target or biomarker	How to understand its role
Breast cancer	Enhertu; Kadcyla; Trodelvy; Datroway	HER2 or TROP2	Different ADCs address HER2-positive disease, selected HER2-low or HER2-ultralow disease, hormone receptor-positive/HER2-negative disease and triple-negative breast cancer in defined treatment settings.
Non-small cell lung cancer	Enhertu; Datroway	HER2/ERBB2 mutation or a defined EGFR-mutated disease setting	Selected patients with advanced disease after specified prior treatment may be eligible. These ADCs are not treatments for every lung cancer.
Gastric and gastroesophageal junction cancer	Enhertu	HER2-positive disease	An option for selected adults with advanced or metastatic disease after prior trastuzumab-based treatment.
Bladder and other urothelial cancers	Padcev	Nectin-4-directed ADC	Enfortumab vedotin is used in combination with pembrolizumab in established advanced-disease settings; a perioperative indication for muscle-invasive bladder cancer was added in 2026.
Ovarian, fallopian tube and primary peritoneal cancer	Elahere	Folate receptor alpha (FRα)	For selected adults with FRα-positive, platinum-resistant disease and a defined prior-treatment history.
Cervical cancer	Tivdak	Tissue factor	For recurrent or metastatic disease progressing on or after chemotherapy.
Acute myeloid leukemia (AML)	Mylotarg	CD33	Used in specified CD33-positive AML treatment settings.
B-cell acute lymphoblastic leukemia (B-ALL)	Besponsa	CD22	For selected patients with CD22-positive B-cell precursor ALL, including relapsed or refractory disease.
Hodgkin lymphoma and selected other lymphomas	Adcetris	CD30	Used in several defined lymphoma settings, including Hodgkin lymphoma and selected CD30-positive lymphomas.
Diffuse large B-cell lymphoma (DLBCL)	Polivy; Zynlonta; selected Adcetris combinations	CD79b, CD19 or CD30, respectively	Different products are used in distinct first-line or relapsed/refractory treatment settings. They are not interchangeable.
Multiple myeloma	Blenrep	BCMA	Belantamab mafodotin was approved in 2025 in a combination regimen for selected relapsed or refractory disease, with important eye-safety requirements.
Blastic plasmacytoid dendritic cell neoplasm (BPDCN)	Decnupaz	CD123	Pivekimab sunirine was FDA-approved in May 2026 for adults with this rare hematologic malignancy.

Regulatory references: Enhertu in early-stage breast cancer, Trodelvy in first-line triple-negative breast cancer, Datroway in triple-negative breast cancer, Padcev-based perioperative treatment for muscle-invasive bladder cancer and Decnupaz for BPDCN.

5. Breast Cancer: Several ADCs, Different Roles

Breast cancer is one of the clearest examples of why ADC treatment should be personalized. Two patients with breast cancer may have very different treatment options because their tumours differ in HER2 status, hormone receptor status, disease stage and previous treatment.

Enhertu: trastuzumab deruxtecan (T-DXd)

Enhertu is an ADC directed against HER2 that carries a topoisomerase I inhibitor payload.

Its FDA-approved uses span several settings, including:

• HER2-positive advanced or metastatic breast cancer: A first-line option in combination with pertuzumab was approved on December 15, 2025, for adults with unresectable or metastatic HER2-positive disease identified by an FDA-authorized test.
• Selected early-stage HER2-positive breast cancer: In May 2026, the FDA approved a neoadjuvant regimen of Enhertu followed by taxane, trastuzumab and pertuzumab for Stage II or III disease, and an adjuvant indication for patients with residual invasive disease after specified neoadjuvant therapy.
• HR-positive, HER2-low or HER2-ultralow advanced breast cancer: An option for eligible patients whose disease has progressed following one or more endocrine therapies in the metastatic setting.
• Other previously treated HER2-positive disease: Eligibility depends on the particular indication, tumour characteristics and treatment history.

The 2025 first-line metastatic approval is described in the FDA's Enhertu plus pertuzumab approval notice. The 2026 early-stage indications are described in the FDA's early-stage breast cancer approval notice.

Kadcyla: trastuzumab emtansine (T-DM1)

Kadcyla is another HER2-directed ADC, but its payload and clinical evidence differ from those of Enhertu. It is used in specified HER2-positive breast cancer settings, including residual invasive disease following certain neoadjuvant treatments and selected metastatic disease after prior HER2-directed treatment.

Enhertu and Kadcyla should not be viewed as interchangeable versions of the same medicine. The appropriate product depends on the disease setting, clinical evidence, regulatory indication and the patient's history.

Trodelvy: sacituzumab govitecan

Trodelvy targets TROP2 and delivers a topoisomerase I inhibitor payload. Its FDA-approved breast cancer indications include particular settings of triple-negative and hormone receptor-positive/HER2-negative advanced breast cancer.

In June 2026, the FDA expanded its role in first-line unresectable locally advanced or metastatic triple-negative breast cancer:

• Trodelvy alone for adults who are not candidates for PD-1/PD-L1 inhibitor-based treatment.
• Trodelvy combined with pembrolizumab, or with the relevant pembrolizumab formulation, for adults whose tumours meet the specified PD-L1 combined positive score (CPS ≥10) criterion using an FDA-authorized test.

See the FDA's June 2026 Trodelvy approval announcement.

Datroway: datopotamab deruxtecan

Datroway is another TROP2-directed ADC. Its FDA-approved uses include selected adults with HR-positive/HER2-negative advanced breast cancer following endocrine-based therapy and chemotherapy. A separate indication was approved in May 2026 for adults with unresectable or metastatic triple-negative breast cancer who are not candidates for PD-1/PD-L1 inhibitor treatment.

Its approved use in triple-negative breast cancer is described in the FDA's Datroway approval notice.

What breast cancer patients should know: HER2 status is not a simple positive-versus-negative decision across all treatments. HER2-positive, HER2-low and HER2-ultralow classifications can have different meanings for drug eligibility. A report should be interpreted alongside the specific FDA label and, where appropriate, confirmatory or companion diagnostic testing.

6. Lung Cancer: ADC Eligibility Depends on the Molecular Setting

ADCs are not general treatments for all lung cancers. The established indications described below apply to selected forms of advanced non-small cell lung cancer (NSCLC).

Enhertu for HER2-mutant NSCLC

The FDA granted accelerated approval to trastuzumab deruxtecan for adults with unresectable or metastatic NSCLC whose tumours harbour an activating HER2 (ERBB2) mutation detected by an FDA-approved test, after prior systemic therapy.

This is a mutation-defined indication. HER2 mutation status is not synonymous with HER2 protein overexpression, so the molecular finding and testing method matter.

Datroway for EGFR-mutated NSCLC

Datopotamab deruxtecan received accelerated FDA approval in June 2025 for adults with locally advanced or metastatic EGFR-mutated NSCLC following prior EGFR-directed treatment and platinum-based chemotherapy.

Although Datroway targets TROP2, its approved NSCLC indication is defined by a particular clinical and molecular setting, including EGFR mutation status and previous treatment. It should not be interpreted as an indication for all TROP2-expressing lung cancers.

Read the FDA's Datroway approval notice for EGFR-mutated NSCLC.

7. Gastric and Gastroesophageal Junction Cancer

Enhertu for HER2-positive gastric or GEJ adenocarcinoma

Trastuzumab deruxtecan has an FDA-approved role in adults with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma after a prior trastuzumab-based regimen.

This does not mean that Enhertu is indicated for every stomach cancer. Many gastric cancers are HER2-negative, and treatment decisions also depend on disease extent, pathology, prior treatment, overall health and available alternatives.

See the FDA approval notice for HER2-positive gastric and GEJ adenocarcinoma.

8. Bladder and Urothelial Cancer

Padcev: enfortumab vedotin

Padcev is an ADC directed against Nectin-4 and is an important treatment in defined urothelial cancer settings.

For locally advanced or metastatic urothelial cancer, the combination of enfortumab vedotin and the immune checkpoint inhibitor pembrolizumab received traditional FDA approval in December 2023. The trial supporting that approval demonstrated better progression-free and overall survival than platinum-based chemotherapy in the studied population.

In July 2026, the FDA expanded the perioperative role of pembrolizumab-based treatment with enfortumab vedotin to adults with muscle-invasive bladder cancer who are candidates for cystectomy. The regimen includes treatment before surgery and subsequent treatment after surgery, according to the approved indication.

These are separate treatment settings: advanced disease and treatment around surgery for muscle-invasive bladder cancer. See the FDA's advanced urothelial cancer approval notice and 2026 muscle-invasive bladder cancer approval notice.

9. Ovarian, Fallopian Tube and Primary Peritoneal Cancer

Elahere: mirvetuximab soravtansine

Elahere targets folate receptor alpha (FRα) and carries a microtubule inhibitor payload.

Its FDA-approved indication is for adults with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer who have received one to three prior systemic treatment regimens. Eligibility is based on the required FRα test.

This illustrates an essential principle: the cancer diagnosis alone is insufficient. An eligible patient must also meet the molecular testing and previous-treatment criteria for the drug.

Read the FDA's approval notice for Elahere.

10. Cervical Cancer

Tivdak: tisotumab vedotin

Tivdak is a tissue-factor-directed ADC. The FDA granted it traditional approval in April 2024 for recurrent or metastatic cervical cancer that has progressed on or after chemotherapy.

As with all ADCs, the existence of a product for a particular cancer does not mean it is the right option at every stage or line of treatment. The patient's previous treatments, disease progression, other health conditions and specific treatment risks should guide the decision.

See the FDA's Tivdak approval notice.

11. Blood Cancers: Leukemia, Lymphoma and Multiple Myeloma

ADCs are not limited to solid tumours. They are also used in several blood cancers, where surface proteins on malignant blood cells can serve as treatment targets.

Acute myeloid leukemia: Mylotarg

Gemtuzumab ozogamicin (Mylotarg) targets CD33 and carries a cytotoxic payload. It is used in selected CD33-positive acute myeloid leukemia treatment settings.

Suitability depends on the exact AML subtype, disease setting, age, other treatments and the prescribing information. A diagnosis of AML alone does not automatically establish eligibility.

B-cell acute lymphoblastic leukemia: Besponsa

Inotuzumab ozogamicin (Besponsa) targets CD22 and has an approved role in CD22-positive B-cell precursor acute lymphoblastic leukemia, including relapsed or refractory disease in eligible patients.

The FDA approved its use in pediatric patients aged one year and older with relapsed or refractory CD22-positive B-cell precursor ALL in March 2024. The specific adult and pediatric indications should be checked against the current prescribing information.

See the FDA's pediatric Besponsa approval notice.

Hodgkin lymphoma and selected other lymphomas: Adcetris

Brentuximab vedotin (Adcetris) targets CD30. Its approved uses include selected patients with Hodgkin lymphoma and other specified CD30-positive lymphomas. Additional combinations and indications cover defined large B-cell lymphoma treatment settings.

CD30 status, lymphoma subtype, treatment history and the intended combination are important; these indications cannot be transferred automatically from one lymphoma diagnosis to another.

Diffuse large B-cell lymphoma: Polivy and Zynlonta

Polatuzumab vedotin (Polivy) targets CD79b. In the United States, it is used with a combination regimen that includes rituximab, cyclophosphamide, doxorubicin and prednisone for eligible adults with previously untreated DLBCL, not otherwise specified, or high-grade B-cell lymphoma with the specified International Prognostic Index criterion.

Loncastuximab tesirine (Zynlonta) targets CD19 and has an approved role in selected adults with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy.

Both treatments illustrate how ADCs can enter at different points in a cancer's treatment pathway. A first-line combination and a treatment for relapsed disease should not be considered equivalent.

For reference, see the FDA's Polivy approval notice and the current FDA label for Zynlonta.

Multiple myeloma: Blenrep

Belantamab mafodotin (Blenrep) is a BCMA-directed ADC. In October 2025, the FDA approved it in combination with bortezomib and dexamethasone for eligible adults with relapsed or refractory multiple myeloma who have received at least two prior lines of therapy, including a proteasome inhibitor and an immunomodulatory agent.

There is an important regulatory history: the previous accelerated-approval indication for Blenrep was withdrawn in 2023 after the confirmatory trial failed to verify the required clinical benefit. The later approval concerns a different treatment regimen and indication.

Blenrep has a prominent ocular-toxicity warning and requires specified eye-monitoring procedures. See the FDA's 2025 Blenrep approval notice.

BPDCN: Decnupaz

Pivekimab sunirine (Decnupaz) is a CD123-directed antibody and alkylating-agent conjugate. The FDA approved it on May 27, 2026, for adults with blastic plasmacytoid dendritic cell neoplasm, a rare and aggressive hematologic malignancy.

The FDA's clinical summary reported complete remission or clinical complete remission in 69.7% of patients with previously untreated disease in the evaluated trial population. This was a trial-specific response outcome, not a guarantee of benefit for an individual patient; duration of response, later treatment needs and the patient's overall clinical situation remain important.

The prescribing information includes a boxed warning for hepatotoxicity, including hepatic veno-occlusive disease. Read the FDA's Decnupaz approval notice.

12. Can ADCs Treat Cancers Beyond These Examples?

Yes, in carefully defined circumstances. Some ADCs are being investigated in additional solid and blood cancers. Some approved ADCs also have tumour-agnostic indications, which are based on a specific molecular characteristic across more than one cancer type.

For example, the FDA granted accelerated approval to Enhertu in April 2024 for eligible adults with unresectable or metastatic HER2-positive solid tumours defined as IHC 3+, following prior systemic treatment and where there are no satisfactory alternative treatment options.

That is a specific regulatory indication. It does not mean every HER2-expressing tumour, every HER2 mutation or every patient with an advanced cancer can receive Enhertu under that approval.

Review the FDA's tumour-agnostic Enhertu approval notice for the exact criteria.

In other cancers, an ADC may be available only in a clinical trial. The presence of a target in laboratory research does not establish that a drug will benefit patients in routine practice.

13. Which Biomarker Tests Matter Before ADC Treatment?

Biomarker testing helps identify the treatment options most relevant to a particular cancer. The required test depends on the ADC and the indication, rather than on the general concept of ADC treatment.

Biomarker or finding	Why it matters	Example of a treatment context
HER2 protein expression or gene amplification	Can establish eligibility for particular HER2-directed ADC indications.	Enhertu or Kadcyla in specific breast cancer settings.
HER2-low or HER2-ultralow status	May affect eligibility for selected HER2-directed treatment indications even when a tumour is not classified as HER2-positive.	Enhertu in eligible HR-positive advanced breast cancer.
HER2/ERBB2 mutation	Identifies a molecular alteration that can support eligibility for a mutation-defined treatment.	Enhertu in selected previously treated HER2-mutant NSCLC.
FRα expression	Used to identify eligible patients for a particular ovarian cancer ADC indication.	Elahere in FRα-positive, platinum-resistant ovarian, fallopian tube or primary peritoneal cancer.
EGFR mutation	Can define the NSCLC clinical setting for a specific ADC indication after prior therapies.	Datroway in eligible previously treated EGFR-mutated NSCLC.
PD-L1 combined positive score	Helps determine eligibility for certain immune checkpoint inhibitor treatment regimens.	Trodelvy combined with pembrolizumab in the specified first-line TNBC setting.
CD19, CD22, CD30, CD33, CD79b or BCMA	These targets help define the biology and treatment options for particular blood cancers.	Selected leukemia, lymphoma and multiple myeloma indications.

Not every target requires a separate companion diagnostic test for every approved indication. Some drugs require a specific test, while other indications are defined by pathology, tumour subtype and treatment history. Always check the current product label.

Patients can ask their oncology team whether existing tissue is adequate for testing, whether a new biopsy is needed, whether a liquid biopsy is appropriate for the clinical question, and whether the result is sufficient for the exact treatment being considered.

14. What Are the Side Effects of ADCs?

ADCs can be effective, but their side effects should not be underestimated. A drug's risk profile depends on the antibody target, payload, linker, dose, treatment schedule, combinations and the patient's health.

Some reactions overlap with conventional chemotherapy. Others are particularly important for certain ADC products.

Potential adverse effect	Why it can occur	What patients should know
Low blood-cell counts	Cytotoxic payloads may damage bone marrow cells.	Blood tests and monitoring for infection, anaemia and bleeding may be required.
Nausea, vomiting, diarrhoea or fatigue	Systemic exposure to the drug payload and other treatment effects.	Preventive medicines and early supportive care may help. Severe or persistent symptoms require assessment.
Peripheral neuropathy	Some payloads interfere with microtubules and can damage peripheral nerves.	Report numbness, tingling, weakness, pain or changes in walking and dexterity.
Eye toxicity	Some ADCs affect the ocular surface or corneal epithelium.	Certain treatments require eye examinations and dose management. New visual changes should be reported promptly.
Interstitial lung disease or pneumonitis	Potentially serious inflammation or injury involving lung tissue is a recognised risk of certain ADCs.	New or worsening cough, breathlessness, chest symptoms or fever need urgent clinical assessment, especially during treatment.
Skin reactions	Some ADCs can cause significant rashes and other skin toxicity.	Report rapidly worsening rash, blistering, skin pain, peeling or mouth/eye involvement immediately.
Liver injury	Some products can cause elevated liver enzymes or other liver complications.	Monitoring may include liver blood tests; symptoms such as jaundice or dark urine need prompt assessment.
Infusion-related reactions	Reactions may occur during or shortly after administration.	Tell the treatment team about breathing difficulties, flushing, dizziness, fever or other sudden symptoms during infusion.

Why interstitial lung disease deserves special attention

Some ADCs carrying deruxtecan-related payloads have important warnings for interstitial lung disease (ILD) and pneumonitis. These conditions can be serious and, in some cases, life-threatening.

A new cough or unexplained shortness of breath during treatment should not automatically be dismissed as fatigue, a respiratory infection or cancer progression. Contact the treating oncology team urgently for advice and assessment. Severe breathing difficulty requires emergency medical care.

Why eye monitoring matters

Ocular toxicity is especially important for certain ADCs, including mirvetuximab soravtansine and belantamab mafodotin. Depending on the product, the care plan may include baseline examinations, repeat eye checks, lubricating eye drops, symptom monitoring and dose changes.

Do not wait for a routine appointment if you develop blurred vision, eye pain, marked light sensitivity or other new visual symptoms during treatment.

Does an ADC cause fewer side effects than chemotherapy?

Not necessarily. The intended benefit is more targeted drug delivery, not guaranteed freedom from toxicity. Some ADCs have a more manageable safety profile for a particular patient than a comparator treatment; others have distinctive serious risks.

The fairest comparison is between the actual treatments that are appropriate for a particular cancer, at a particular disease stage, using evidence from the relevant clinical trials. A general statement that all ADCs are safer than chemotherapy is not justified.

15. How Do Doctors Decide Whether an ADC Is Appropriate?

The decision is usually based on several elements considered together, rather than on one biomarker alone.

1. Confirm the diagnosis. Review the tumour type, histology, stage and other features that may affect treatment.
2. Review the biomarker results. Confirm that the test and result satisfy the drug's specific eligibility criteria.
3. Check prior treatment. Some ADCs are used early; others require progression after specified therapies.
4. Assess health and organ function. Blood counts, liver function, kidney function, lung history, neuropathy and eye health may influence risk.
5. Compare realistic alternatives. Consider established treatments, including surgery, radiotherapy, conventional chemotherapy, targeted therapies, immunotherapy, other ADCs and clinical trials, as appropriate.
6. Discuss the treatment goal. The objective may be cure, reducing recurrence risk, controlling advanced disease, relieving symptoms or extending survival.
7. Plan monitoring before treatment begins. Establish the necessary blood tests, scans, eye examinations or symptom checks.

For patients with complex cancers or several potential treatment options, a multidisciplinary oncology review or a second opinion from a relevant specialist may help clarify the evidence and the sequence of care.

16. Questions to Ask Your Oncologist About an ADC

• What is the exact generic name and brand name of the ADC being proposed?
• What target does it recognise, and does my tumour meet the relevant eligibility criteria?
• Was the required biomarker test performed on the appropriate tissue or sample?
• Is this treatment approved for my specific cancer type, stage and treatment history in my country?
• Is it being used alone or in combination with chemotherapy, immunotherapy or another targeted drug?
• What benefits were demonstrated in patients like me, and what remains uncertain?
• What are the most important serious side effects of this specific ADC?
• What symptoms should prompt an immediate call, an urgent hospital assessment or emergency care?
• What monitoring will be required, including blood tests, scans or eye examinations?
• What alternatives are available, including other standard treatments and suitable clinical trials?

17. How Strong Is the Evidence for ADCs?

ADCs are an important advance in cancer treatment, but evidence should be assessed drug by drug and indication by indication.

Useful questions include:

• Was the ADC tested in a randomised controlled trial or primarily in a single-arm study?
• What was the comparison group, and was it an appropriate standard of care?
• Did the study demonstrate a meaningful improvement in overall survival, progression-free survival, quality of life or another relevant outcome?
• How serious were adverse effects, and how often did patients stop treatment because of toxicity?
• Were the trial participants similar to the patient being treated?
• Is the approval traditional or accelerated, and what confirmatory evidence remains necessary?

Response rate, progression-free survival and overall survival are different outcomes. A tumour shrinking on a scan does not by itself establish that a treatment extends life. Similarly, a statistically significant result does not automatically mean the improvement is large enough to be important to every patient.

Accelerated approval can provide earlier access to a promising treatment for a serious condition, but it may involve outstanding requirements to verify clinical benefit. Regulatory status can change as confirmatory evidence emerges.

For U.S. indications, the FDA's ongoing accelerated-approval database, verified clinical-benefit database and withdrawn-approval database help track these distinctions.

18. Frequently Asked Questions About ADCs

Are antibody-drug conjugates a type of chemotherapy?

ADCs combine an antibody with an attached anticancer drug payload, and many payloads are cytotoxic. They are therefore distinct from conventional chemotherapy delivery, but they still carry important chemotherapy-like risks, including low blood counts and other systemic toxicities.

Do ADCs work only when a tumour has very high biomarker expression?

It depends on the drug and its approved indication. Some treatments require high expression or a defined positive result; others use different criteria. HER2-positive, HER2-low and HER2-ultralow breast cancer provide a useful example of why the test result must be interpreted against the specific treatment label.

Can an ADC cure cancer?

Some ADCs are used with curative intent in defined early-stage treatment plans, while others aim to control advanced disease. The word “ADC” alone says nothing about the likelihood of cure. That depends on the cancer, stage, treatment regimen and evidence for that particular setting.

Can an ADC stop working even when the original target is present?

Yes. Resistance may arise through changes in target expression, drug uptake, intracellular processing, payload sensitivity or other biological mechanisms. Target positivity does not guarantee a response.

Can ADCs be combined with immunotherapy?

Yes. Some approved regimens combine an ADC with an immune checkpoint inhibitor, such as enfortumab vedotin with pembrolizumab in urothelial cancer and selected sacituzumab govitecan-based treatment in triple-negative breast cancer. These combinations have specific indications and must not be generalised to other cancers.

Are ADCs available in every country?

No. Approvals, available products, eligible indications, reimbursement and access to companion diagnostic tests vary by jurisdiction. A U.S. FDA approval does not automatically mean that the same indication is approved or funded elsewhere.

Are all targeted cancer drugs ADCs?

No. Oral targeted inhibitors, unconjugated monoclonal antibodies, bispecific antibodies, CAR T-cell therapies and radioligand treatments are different therapeutic categories. The defining feature of an ADC is the antibody chemically linked to a drug payload.

What should I do if I develop breathing problems or vision changes during ADC treatment?

Contact the oncology team urgently. New breathing difficulty can indicate a serious lung complication, while new visual symptoms may signal ocular toxicity. Severe breathing difficulty, rapidly worsening symptoms or another medical emergency requires immediate emergency care.

Conclusion: The Right ADC for the Right Cancer Setting

Antibody-drug conjugates represent a major development in precision oncology because they combine molecular recognition with potent anticancer payloads. Their established uses now span multiple solid tumours and blood cancers, with new indications continuing to emerge.

However, ADCs are not universally effective, perfectly selective or free from serious toxicity. Their value depends on matching a specific medicine to the correct tumour biology, treatment setting and patient, then monitoring carefully for both benefit and harm.

For patients and caregivers, the most useful next step is to establish the exact cancer diagnosis, understand the relevant biomarker results, confirm the approved indication and compare the expected benefits and risks with other appropriate options.

Medical disclaimer: This article is for education and is not personal medical advice. It does not replace consultation with a qualified oncology team. Treatment eligibility, regulatory approval and prescribing information can change. Never start, stop or substitute an anticancer treatment without discussing it with the treating clinician.

References and Further Reading

1. National Cancer Institute: Antibody-drug conjugate definition.
2. FDA: Enhertu in early-stage HER2-positive breast cancer, May 2026.
3. FDA: Trodelvy in first-line triple-negative breast cancer, June 2026.
4. FDA: Datroway in triple-negative breast cancer, May 2026.
5. FDA: Perioperative enfortumab vedotin-based treatment for muscle-invasive bladder cancer, July 2026.
6. FDA: Mirvetuximab soravtansine in FRα-positive, platinum-resistant ovarian cancer.
7. FDA: Pivekimab sunirine for BPDCN, May 2026.
8. FDA: Belantamab mafodotin for relapsed or refractory multiple myeloma, October 2025.
9. FDA: Ongoing cancer accelerated approvals.
10. FDA: Drugs@FDA and approved prescribing information.

Editorial note: This guide summarises selected indications rather than every ADC, label revision or national approval. Always check the latest prescribing information for the exact medicine and indication.