PEMBROLIZUMAB (KEYTRUDA)
FOR CANCER TREATMENT
Prepared by the CancerFax oncology navigation team. Updated regularly based on treatment access and clinical availability.
What Pembrolizumab Is and How It Works
Pembrolizumab is a humanised monoclonal antibody that targets PD-1 (Programmed Death-1), a protein on T cells. Cancer cells often display PD-L1 or PD-L2, which bind to PD-1 and switch off T cells before they can attack the tumour. By blocking PD-1, pembrolizumab keeps T cells active and allows the immune system to recognise and destroy cancer cells. It belongs to the broader class of immune checkpoint inhibitors. Pembrolizumab was first approved in 2014 for advanced melanoma and has since become one of the most widely studied cancer drugs in history, with approvals expanding into many solid tumours and selected blood cancers. It can be used as a single agent or combined with chemotherapy, targeted therapy, another immunotherapy, or radiation, depending on the cancer type and stage.
Cancers Where Pembrolizumab May Be Considered
Approved or commonly used indications include: Specific approved indications, line of therapy, and biomarker thresholds vary by country.
Melanoma β advanced disease and adjuvant after surgery
Melanoma β advanced disease and adjuvant after surgery
Non-small cell lung cancer β as monotherapy or with chemothe
Non-small cell lung cancer β as monotherapy or with chemotherapy
Head and neck squamous cell carcinoma
Head and neck squamous cell carcinoma
Urothelial (bladder) carcinoma
Urothelial (bladder) carcinoma
Hodgkin lymphoma and primary mediastinal large B-cell lympho
Hodgkin lymphoma and primary mediastinal large B-cell lymphoma
Gastric and gastroesophageal junction cancer
Gastric and gastroesophageal junction cancer
Oesophageal cancer
Oesophageal cancer
Cervical cancer
Cervical cancer
Endometrial carcinoma β alone or with lenvatinib depending o
Endometrial carcinoma β alone or with lenvatinib depending on MMR status
Triple-negative breast cancer
Triple-negative breast cancer
Hepatocellular carcinoma (liver)
Hepatocellular carcinoma (liver)
Renal cell carcinoma β usually combined with axitinib or len
Renal cell carcinoma β usually combined with axitinib or lenvatinib
How Pembrolizumab Is Given
Pembrolizumab is given as an intravenous infusion lasting around 30 minutes. The most common dosing schedules are 200 mg every three weeks or 400 mg every six weeks; some adjuvant and paediatric protocols use weight-based dosing. Treatment typically continues for up to two years, or until disease progression or significant side effects. Patients are monitored with imaging, blood tests, and clinical reviews at scheduled intervals.
Who May Be Suitable
Eligibility depends on multiple factors: Some indications require specific PD-L1 thresholds β for example, first-line monotherapy in NSCLC typically requires PD-L1 β₯ 50% under most guidelines β while others allow use regardless of PD-L1 expression. Final eligibility depends on the treating oncologist.
Confirmed cancer type, stage, and current disease status
Confirmed cancer type, stage, and current disease status
PD-L1 expression (CPS, TPS, or IC) where the indication requ
PD-L1 expression (CPS, TPS, or IC) where the indication requires it
MSI-H, dMMR, or TMB-high status when relevant
MSI-H, dMMR, or TMB-high status when relevant
Previous treatment history and response
Previous treatment history and response
Performance status and overall fitness
Performance status and overall fitness
Liver, kidney, lung, and heart function
Liver, kidney, lung, and heart function
Absence of active autoimmune disease (often a relative contr
Absence of active autoimmune disease (often a relative contraindication)
Stable hepatitis B, C, or HIV status if present
Stable hepatitis B, C, or HIV status if present
Not on high-dose immunosuppressive therapy
Not on high-dose immunosuppressive therapy
Not pregnant or breastfeeding
Not pregnant or breastfeeding
Documents Usually Required for Review
The completeness of these reports often determines how quickly an appropriate treatment plan can be built and discussed.
Latest medical summary and oncologistβs opinion
Latest medical summary and oncologistβs opinion
Pathology and IHC reports
Pathology and IHC reports
PD-L1 IHC report (CPS, TPS, or IC, depending on cancer)
PD-L1 IHC report (CPS, TPS, or IC, depending on cancer)
MSI / dMMR testing report
MSI / dMMR testing report
TMB and NGS report, if available
TMB and NGS report, if available
Hepatitis B, C, and HIV status
Hepatitis B, C, and HIV status
Autoimmune disease history, thyroid function, and cortisol w
Autoimmune disease history, thyroid function, and cortisol where relevant
PET CT, CT, or MRI reports
PET CT, CT, or MRI reports
Recent CBC, liver and kidney function tests
Recent CBC, liver and kidney function tests
Treatment history with dates, drugs, and response
Treatment history with dates, drugs, and response
ECG and echocardiogram if cardiac history
ECG and echocardiogram if cardiac history
Current medication list
Current medication list
How CancerFax Helps
CancerFax supports patients exploring pembrolizumab through a structured pathway:
Case review β diagnosis, biomarkers, prior treatments, and c
Case review β diagnosis, biomarkers, prior treatments, and current status are reviewed to assess whether pembrolizumab is an appropriate option.
Protocol mapping β monotherapy, combination, and biosimilar
Protocol mapping β monotherapy, combination, and biosimilar options are identified across countries such as China, India, Germany, and the United States.
Hospital and trial matching β reports are shared with approp
Hospital and trial matching β reports are shared with appropriate oncology teams or trial centres for structured feedback.
Cost and logistics planning β patients receive guidance on d
Cost and logistics planning β patients receive guidance on drug pricing, expected cycles, total duration, accommodation, and stay requirements.
Coordination and follow-up β CancerFax supports admission, i
Coordination and follow-up β CancerFax supports admission, interpreter needs, monitoring schedules, and continuity after returning home.
Important Limitations and Side Effects
Pembrolizumab can cause immune-related adverse events (irAEs), because immune activation against the cancer can also affect healthy organs: Most irAEs are manageable with steroids and treatment hold, but some are serious and a few can be life-threatening. Side effects can occur during treatment or weeks to months after stopping. Response rates vary widely by cancer type and biomarker status, and outcomes cannot be guaranteed.
Skin β rash, itching, vitiligo
Skin β rash, itching, vitiligo
Gastrointestinal β colitis, diarrhoea
Gastrointestinal β colitis, diarrhoea
Lung β pneumonitis
Lung β pneumonitis
Liver β hepatitis
Liver β hepatitis
Endocrine β thyroid disorders, hypophysitis, adrenal insuffi
Endocrine β thyroid disorders, hypophysitis, adrenal insufficiency, type 1 diabetes
Kidney β nephritis
Kidney β nephritis
Heart β rare but serious myocarditis
Heart β rare but serious myocarditis
Neurologic β encephalitis and neuropathy in rare cases
Neurologic β encephalitis and neuropathy in rare cases
Infusion reactions β uncommon, usually manageable
Infusion reactions β uncommon, usually manageable
Where This May Be Available
Pembrolizumab is widely available in major cancer centres across the United States, Europe, Japan, China, India, Singapore, Australia, and other regions, although approved indications and reimbursement rules differ by country. CancerFax is most useful when a specific indication is not approved or accessible locally, when a patient is considering a combination protocol or biomarker-guided regimen unavailable at home, when more affordable PD-1 access is being explored in China or India, or when newer trial-only combinations involving LAG-3, TIGIT, or other novel agents are relevant. The right hospital, oncology team, and protocol matter as much as the country itself.
Frequently Asked Questions
Answers to common questions from patients and families.
Is pembrolizumab a cure for cancer?
For some patients with cancers like melanoma, MSI-H tumours, and certain lung cancers, pembrolizumab can produce long-lasting remissions. However, response cannot be guaranteed, many patients do not respond, and some develop resistance. The outcome depends heavily on cancer type, biomarker status, and overall health. Pembrolizumab should be viewed as a meaningful option for selected patients, not a universal cure.
How is pembrolizumab different from other PD-1 inhibitors?
Pembrolizumab, nivolumab, cemiplimab, dostarlimab, and the China-approved agents such as tislelizumab and sintilimab all target PD-1 but differ in approved indications, dosing, and pricing. Clinically they are often comparable within similar indications, but specific protocols and country approvals vary. The choice depends on cancer type, biomarker, country of treatment, and the treating oncologistβs preference.
Do I need PD-L1 testing before pembrolizumab?
It depends on the cancer. Some indications (such as first-line NSCLC monotherapy and gastric cancer) require specific PD-L1 thresholds. Others (such as MSI-H tumours, melanoma, and renal cancer combinations) do not. PD-L1 testing should ideally be available before treatment is decided, as it influences both eligibility and the choice between pembrolizumab alone or with chemotherapy.
How long will I need to take pembrolizumab?
Most patients receive pembrolizumab for up to two years, sometimes longer, until progression or significant toxicity. Adjuvant protocols after surgery often have fixed durations, typically around one year. Some patients stop earlier if a strong, durable response is achieved. The decision to stop or continue is made by the treating oncologist based on response and tolerance.
Is pembrolizumab cheaper in China or India?
Pembrolizumab is generally more affordable in India and several Asian markets than in the United States or parts of Europe, although it remains an expensive drug. In China, several domestic PD-1 inhibitors are available at substantially lower cost and may be clinically acceptable alternatives. CancerFax helps patients evaluate the cost-effective and medically appropriate option for their case.
Can pembrolizumab be combined with chemotherapy?
Yes. Pembrolizumab is approved with chemotherapy in non-small cell lung cancer, triple-negative breast cancer, gastric cancer, oesophageal cancer, head and neck cancer, and several other indications. It is also combined with targeted therapy (such as lenvatinib or axitinib in kidney cancer). Combinations can improve outcomes but increase side effect risk; the right choice depends on cancer type, biomarker, and patient condition.
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination β travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
Need Help Understanding Your Options?
If you or a family member is exploring pembrolizumab or any PD-1 immunotherapy, CancerFax can help organise the medical records, review biomarker reports, and connect the case with suitable oncologists, hospitals, or clinical trial teams. Share your reports to receive structured guidance before making travel or treatment decisions. CTAs: Share Your Reports | Request a Second Opinion | Explore
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.