CANCER IMMUNOTHERAPY:
HARNESSING YOUR IMMUNE SYSTEM AGAINST CANCER

Cancer immunotherapy uses the body's own immune system to locate and destroy cancer cells — not by poisoning them (chemotherapy) or burning them (radiation), but by restoring and amplifying the immune surveillance that cancer has learned to evade.

“Cancer immunotherapy is not a single drug. It is a whole family of treatments — the first question is to determine which one is right for a given patient.”

• How Cancer Evades the Immune System

  Cancer cells downregulate MHC class I molecules (hiding their identity cards), express PD-L1 to tell T-cells to 'stand down', recruit immunosuppressive cells into the tumour microenvironment, and secrete cytokines like TGF-beta and IL-10 — actively turning off immune surveillance.

• What Immunotherapy Does

  Different immunotherapy classes each address a different immune evasion mechanism: checkpoint inhibitors remove the brakes, CAR-T therapy bypasses detection requirements, cancer vaccines provide a precise 'wanted poster', and TIL therapy amplifies the soldiers already inside the tumour.

• Why It Changed Oncology

  Before checkpoint inhibitors in the 2010s, metastatic melanoma had a median survival of months. With immunotherapy, a meaningful proportion of patients achieved multi-year remissions. Approved for 12+ cancer types, immunotherapy is now first-line standard of care for many major cancers.

• Biomarker-Driven Selection

  Unlike chemotherapy given broadly to all patients with a cancer type, immunotherapy is most effective when informed by biomarker testing — PD-L1 expression, MSI/MMR status, TMB — which identify which patients are most likely to respond.

Each type has unique mechanisms, approved indications, administration routes, and side-effect profiles. Understanding the differences is essential before exploring any specific treatment.

• 1. Immune Checkpoint Inhibitors (ICIs)

  Monoclonal antibodies that block PD-1, PD-L1, or CTLA-4 — the inhibitory checkpoints that cancer exploits. The most widely used immunotherapy class today. Key agents: pembrolizumab (Keytruda), nivolumab (Opdivo), atezolizumab (Tecentriq), ipilimumab (Yervoy), durvalumab (Imfinzi). Approved across melanoma, NSCLC, bladder, HNSCC, RCC, CRC (MSI-H), TNBC, gastric, HCC, and more.

• 2. CAR-T Cell Therapy

  A patient's T-cells are collected, genetically engineered to express a synthetic cancer-targeting receptor (CAR), expanded to millions, and reinfused. FDA-approved for B-cell ALL, DLBCL, FL, MCL, and multiple myeloma. Manufacturing takes 3–6 weeks; most effective in blood cancers; active research into solid tumour applications.

• 3. Therapeutic Cancer Vaccines

  Train the immune system to recognise and destroy cancer cells already present. Types include dendritic cell vaccines (sipuleucel-T for prostate cancer — the only FDA-approved therapeutic cancer vaccine), peptide vaccines, viral vector vaccines, and personalised mRNA neoantigen vaccines (mRNA-4157, KEYNOTE-942 — 44% recurrence reduction in melanoma).

• 4. Adoptive Cell Therapy (TIL & Others)

  Tumour-infiltrating lymphocytes (TILs) are extracted from the patient's tumour, expanded billions-fold in a lab, and reinfused after lymphodepletion. FDA-approved as lifileucel (Amtagvi) for advanced melanoma since 2024. No genetic engineering — TILs retain natural multi-antigen diversity. Active trials in cervical, NSCLC, and colorectal cancers.

• 5. Bispecific Antibodies

  Engineered antibodies that simultaneously bind a cancer cell protein and a T-cell protein (CD3), physically bringing T-cells into direct contact with cancer cells to trigger killing — without requiring MHC presentation. Blinatumomab (B-cell ALL) is the landmark example. Active development in both blood cancers and solid tumours.

• 6. Cytokine Therapies

  High-dose IL-2 (interleukin-2) was one of the first cancer immunotherapies — producing durable complete responses in a subset of melanoma and kidney cancer patients. Now largely replaced by checkpoint inhibitors due to severe toxicity. Engineered cytokine fusion proteins and IL-15 agonists are in active clinical development with better tolerability profiles.

• 7. Oncolytic Virus Therapy

  Genetically engineered viruses that selectively infect and destroy cancer cells while sparing normal tissue — simultaneously releasing tumour antigens to trigger a systemic anti-tumour immune response. T-VEC (talimogene laherparepvec, Imlygic) is FDA-approved for injectable melanoma lesions. Multiple oncolytic virus candidates are in active trials.

Immunotherapy response varies significantly by cancer type, subtype, and biomarker profile. Below are approved indications — biomarker testing is essential before assuming eligibility.

• 15–40%ORR for Single-Agent Checkpoint Inhibitors (Unselected)For biomarker-selected populations (PD-L1-high, MSI-H, TMB-H), response rates are significantly higher.
• 12+Cancer Types with Approved Immunotherapy IndicationsExpanding continuously as new trials read out and biomarker-agnostic approvals broaden eligibility.
• 44%Recurrence Risk Reduction — mRNA-4157 + Pembrolizumab (Melanoma)KEYNOTE-942 Phase IIb trial; personalised mRNA neoantigen vaccine + checkpoint inhibitor combination.
• 97.9%Highest CAR-T ORR — Carvykti in r/r Myeloma (CARTITUDE-1)The most dramatic response rate published for any immunotherapy product to date.

Biomarker testing is what makes immunotherapy a precision treatment — not an across-the-board prescription. These tests determine eligibility, predict likely response, and guide combination strategy.

Immunotherapy eligibility is determined by cancer type, biomarker profile, general health, and prior treatment history. Each patient requires individual assessment.

Immunotherapy is rarely used in isolation. Understanding its position within the treatment plan — and how it combines with other modalities — is critical for setting realistic expectations.

• First-Line Immunotherapy (Monotherapy or Combination)

  For PD-L1-high NSCLC, MSI-H CRC, and first-line advanced melanoma, checkpoint inhibitors are now the standard of care — often replacing chemotherapy entirely for biomarker-selected patients. Combination with chemotherapy is standard for TNBC, gastric, and esophageal cancers.

• Immunotherapy After Prior Treatment (Later Lines)

  In bladder, gastric, and HNSCC, second-line immunotherapy shows durable responses in patients who progressed after platinum-based chemotherapy. For blood cancers, CAR-T is typically used after multiple prior lines of therapy.

• Chemoimmunotherapy (Checkpoint + Chemotherapy)

  The most common first-line combination for NSCLC, TNBC, gastric, and esophageal cancers. Rationale: chemotherapy-induced tumour cell death releases antigens that enhance the immune response triggered by checkpoint inhibitors — a synergistic effect validated across multiple Phase III trials.

• Immunotherapy + Targeted Therapy

  Checkpoint inhibitor plus VEGF inhibitor combinations (nivolumab + ipilimumab; pembrolizumab + axitinib; atezolizumab + bevacizumab) are first-line standards for advanced RCC and HCC — attacking the tumour through both immune mechanisms and angiogenesis inhibition simultaneously.

• Immunotherapy + Radiotherapy (Radioimmunotherapy)

  Radiation induces the 'abscopal effect' — a systemic immune response to tumours not directly irradiated. Combining radiation with checkpoint inhibitors is an active research area with durable locoregional control data in several cancer types.

• Neoadjuvant & Adjuvant Immunotherapy

  Immunotherapy is increasingly used perioperatively. Adjuvant pembrolizumab is approved in high-risk stage II/III melanoma and stage III NSCLC. Neoadjuvant checkpoint combinations are producing pathological complete responses in bladder cancer, TNBC, and NSCLC before surgery.

Immunotherapy side effects are fundamentally different from chemotherapy — they result from immune system activation attacking normal tissues, not direct drug toxicity. Early recognition and management are critical.

• Skin irAEs

  Rash and pruritus are the most common irAEs — occurring in 20–40% of patients on checkpoint inhibitors. Usually Grade 1–2 and manageable with topical steroids. Rare severe manifestations (Stevens-Johnson syndrome) require immediate immunotherapy discontinuation.

• Gastrointestinal irAEs

  Immune-mediated colitis (diarrhoea, abdominal pain) occurs more frequently with anti-CTLA-4 agents and combination checkpoint therapy. Grade 3–4 colitis requires immunotherapy hold and high-dose corticosteroids. Can progress to perforation if unmanaged.

• Endocrine irAEs

  Thyroid dysfunction (hypo/hyperthyroidism) is very common — 5–10% of patients. Hypophysitis and adrenal insufficiency are less common but more severe, requiring lifelong hormone replacement. Baseline and serial thyroid and cortisol monitoring is standard practice.

• Pulmonary irAEs

  Immune-mediated pneumonitis (cough, dyspnoea, decreased exercise tolerance) occurs in 2–5% of patients — higher with combination checkpoint therapy and in lung cancer. Requires CT chest and pulmonologist involvement. Grade 3–4 mandates immunotherapy discontinuation and high-dose IV corticosteroids.

• Hepatic irAEs

  Immune-related hepatitis presents as elevated AST/ALT on routine blood monitoring — usually asymptomatic until advanced. Grade 3–4 hepatitis requires immunotherapy hold, corticosteroids, and hepatology involvement. Baseline LFTs and serial monitoring every 2–4 weeks are standard.

• Combination irAE Risk

  Dual checkpoint inhibition (anti-PD-1 + anti-CTLA-4) carries substantially higher irAE rates than single-agent therapy — particularly for Grade 3–4 colitis, hepatitis, and endocrine toxicity. Patients with prior autoimmune disease, organ transplants, or IBD require specialist assessment before starting.

These three major systemic treatment categories are not mutually exclusive — most patients today receive combinations of two or all three at different points in their treatment journey.

No area of oncology has seen more dramatic results than immunotherapy — but those results are not universal. CancerFax provides honest, evidence-based information without overpromising.

• Durable Responses — The Key Differentiator

  Unlike chemotherapy, whose effects cease when the drug is discontinued, immunotherapy responses in some patients can persist for years after stopping treatment. Multi-year disease-free survival in advanced melanoma and lung cancer was essentially unheard of before checkpoint inhibitors. This durability is immunotherapy's most important clinical advantage.

• Primary Resistance — When It Does Not Work Initially

  Approximately half to two-thirds of patients with immunotherapy-eligible tumours do not respond to initial treatment — called primary resistance. Causes include low tumour antigenicity, immunosuppressive microenvironments, absent tumour-infiltrating lymphocytes, and other resistance mechanisms currently under active research.

• Acquired Resistance — When It Stops Working

  Some patients who initially benefit may eventually experience disease progression — acquired resistance. Management strategies include switching checkpoint agents, adding another immunotherapy modality, or combining with chemotherapy or targeted therapy. Repeat biopsy at progression is increasingly recommended to understand resistance mechanisms.

• Pseudoprogression — Do Not Stop Too Early

  In a small proportion of cases, tumours appear larger on scans after starting immunotherapy before eventually responding — called pseudoprogression. Standard RECIST criteria (designed for chemotherapy) cannot distinguish this from true progression; modified iRECIST criteria and biopsy are used. Stopping immunotherapy during pseudoprogression would be a critical error.

CancerFax serves patients from South Asia, the Middle East, Africa, and Southeast Asia navigating immunotherapy access — from biomarker interpretation to international treatment coordination.

1. 1

   Medical Report Review & Eligibility Assessment

   A thorough review of pathology, imaging, and biomarker reports to assess immunotherapy eligibility — identifying which type of immunotherapy is most appropriate based on cancer type, biomarker profile, and treatment history.

2. 2

   Biomarker Report Interpretation

   Helping patients and families understand what their PD-L1 CPS/TPS, MSI/MMR, TMB, and NGS results mean for treatment decisions — translating laboratory reports into clinically actionable information.

3. 3

   Second Opinion Coordination

   Coordination of second opinions with immunotherapy-experienced oncologists globally — US, Europe, South Korea, China, and India — including remote written reports that the patient's local team can act on without travel.

4. 4

   Connection to Partner Hospitals

   Referral to partner hospitals in the US, Europe, China, South Korea, Japan, and India with proven immunotherapy programmes — matched to tumour type, required agents, and combination strategy.

5. 5

   Clinical Trial Matching

   Identifying open immunotherapy trials globally for which the patient may be eligible — including Phase I/II trials of novel agents, combination strategies, and biomarker-selected studies. CancerFax monitors trial registries continuously.

6. 6

   Travel, Logistics & Follow-Up

   End-to-end coordination for international treatment: visa support, accommodation near the treating centre, airport transfers, multilingual navigation, and post-treatment follow-up between the treating centre and the patient's home oncologist.

Explore in-depth guides on every aspect of cancer immunotherapy.

Frequently Asked Questions

The most common questions from patients and families exploring cancer immunotherapy.