What is the success rate of immunotherapy (immune therapy) for cancer patients?

Immunotherapy Success Rates in Cancer Patients

Immunotherapy response rates vary substantially by cancer type and treatment regimen, ranging from approximately 10-60%, with the highest response rates (approximately 40-60%) occurring in patients with metastatic non-small cell lung cancer who have PD-L1 expression ≥50% and receive single-agent or combination immunotherapy, while most other solid tumors demonstrate objective response rates of 20-40% with immune checkpoint inhibitors. 1, 2, 3

Response Rates by Cancer Type and Treatment Setting

Melanoma

• Single-agent anti-PD-1 therapy (pembrolizumab or nivolumab) achieves objective response rates of 40% in previously untreated metastatic melanoma 3
• Combination nivolumab plus ipilimumab produces response rates of 50% in treatment-naïve patients, with complete response rates of 8.9% 3
• Single-agent ipilimumab demonstrates lower response rates of 14%, though approximately 20% of patients achieve long-term survival (5-year overall survival 18%) 2
• Duration of response is substantial, with 76-77% of responses lasting ≥6 months and 55-56% lasting ≥24 months 3

Non-Small Cell Lung Cancer (NSCLC)

• Response rates are highly dependent on PD-L1 expression levels 1
• Patients with PD-L1 ≥50% achieve approximately 40% response rate to single-agent immunotherapy and approximately 60% to chemoimmunotherapy 1
• Only approximately 30% of patients with metastatic NSCLC have PD-L1 levels ≥50%, limiting the population eligible for optimal response 1
• PD-L1 expression is not an ideal biomarker because some patients with low PD-L1 levels respond to immunotherapy while others with high levels do not respond 1

Microsatellite Instability-High (MSI-H) or Mismatch Repair Deficient (dMMR) Cancers

• Overall objective response rate of 33.3% across all MSI-H/dMMR cancers treated with pembrolizumab 4
• Response rates vary significantly by tumor type 4:
  • Endometrial cancer: 50%
  • Small intestinal cancer: 59%
  • Gastric/GE junction cancer: 39%
  • Biliary cancer: 41%
  • Colorectal cancer: 34%
  • Brain cancer: 4%
• Complete response rate of 10.3% across all MSI-H/dMMR cancers 4
• 77% of responses last ≥12 months and 39% last ≥36 months, demonstrating exceptional durability 4

Virus-Associated Cancers

• Nasopharyngeal carcinoma (EBV-driven) demonstrates 20.5-21% objective response rates with anti-PD-1 monotherapy 2
• 1-year overall survival of 59% and median overall survival of 17.4 months in platinum-refractory disease 2
• Response rates are similar in PD-L1-positive and PD-L1-negative patients (27.1% vs 19.1%, P=0.31), suggesting viral antigens override PD-L1 predictive value 2

Advanced Renal Cell Carcinoma

• Response rates vary by treatment regimen and risk stratification 1
• Combination immunotherapy approaches demonstrate improved quality of life compared to VEGF-targeted therapy despite higher toxicity rates 1

Critical Limitations and Context

Overall Response Patterns

• Objective clinical response rates are usually below 10% in early-stage vaccine trials, preventing meaningful correlations with immune parameters 1
• Only a fraction of patients respond to cell or antigen vaccination, adoptive TIL cell transfer, or antibody therapies, and mechanisms responsible remain unclear 1
• Tumor-specific cellular immune responses often do not correlate with clinical cancer regression despite detection of cytotoxic T cells in vitro 1

Predictive Biomarker Challenges

• Tumor mutational burden (TMB) does not reliably predict response in NSCLC, as overall survival improved with nivolumab plus ipilimumab regardless of TMB or PD-L1 levels 1
• TMB does not identify patients who will respond to chemotherapy, limiting its value for assessing combination immunotherapy plus chemotherapy regimens 1
• High TMB levels do not correlate with PD-L1 expression levels in NSCLC patients 1

Survival Outcomes Beyond Response Rates

Melanoma Long-Term Survival

• Median overall survival not reached in the nivolumab plus ipilimumab arm with 48 months follow-up 3
• Median overall survival of 36.9 months with nivolumab monotherapy versus 19.9 months with ipilimumab 3
• Median progression-free survival of 11.5 months with combination therapy versus 6.9 months with nivolumab monotherapy 3

NSCLC Survival by PD-L1 Status

• Survival benefits occur across PD-L1 expression levels, though magnitude varies 1
• Quality of life is superior with immunotherapy compared to traditional chemotherapy despite treatment-related adverse events 1

Special Populations and Resistance

Solid Organ Transplant Recipients

• Tumor response rates of 25-40% depending on cancer histology subtype 1
• Graft rejection occurs in 37-41% of patients, with graft loss in almost 80% of rejection cases and death due to graft rejection in 38-45% 1
• No association between time after transplantation and risk of organ rejection 1

Mechanisms of Treatment Failure

• Primary resistance (failure to respond from the start) and secondary resistance (relapse after initial response) occur through intrinsic cancer cell factors or tumor microenvironment mechanisms 5
• Immune escape mechanisms create immunosuppressive microenvironments that enhance cancer progression 6

Clinical Algorithm for Interpreting Success Rates

When counseling patients about immunotherapy success rates:

1. Identify cancer type and molecular characteristics (PD-L1 status, MSI-H/dMMR status, TMB, viral association) 1, 2, 4

2. For NSCLC: Expect 40-60% response rates if PD-L1 ≥50%, but only 30% of patients have this level; lower PD-L1 levels still permit response but at reduced rates 1

3. For melanoma: Anticipate 40-50% response rates with modern immunotherapy, with combination therapy trending toward higher responses but increased toxicity 3

4. For MSI-H/dMMR cancers: Expect 33% overall response rate with substantial variation by tumor type (4-59%), but exceptional durability when responses occur 4

5. For virus-associated cancers: Anticipate 20-21% response rates independent of PD-L1 status 2

6. Emphasize response durability: When responses occur, 55-77% last ≥24 months across cancer types, representing potential long-term disease control 3, 4

7. Acknowledge uncertainty: Current biomarkers imperfectly predict individual patient response, and mechanisms of resistance remain incompletely understood 1