KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test.
Clinical Trial Results
Advanced MSI-H/dMMR CRC
KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test.
Clinical Findings from KEYNOTE-177
Kaplan-Meier Estimates of PFS With KEYTRUDA vs Chemotherapyd

Progression-Free Survival (PFS): Double the median PFS with KEYTRUDA
KEYTRUDA (n=153) | Chemotherapy (n=154) |
---|---|
HRg=0.60; 95% CI, 0.45–0.80; Ph=0.0004 | |
Events observed54%(n=82/153) | Events observed73%(n=113/154) |
Median PFS16.5 months(95% CI, 5.4–32.4) | Median PFS8.2 months(95% CI, 6.1–10.2) |
Overall Survival (OS)i Rate
There was no statistically significant difference between KEYTRUDA and chemotherapy in the final OS analysis. Sixty percent of the patients who had been randomized to receive chemotherapy had crossed over to receive subsequent anti–PD-1/PD-L1 therapies including KEYTRUDA. Median follow-up time at the final analysis was 38.1 months (range: 0.2 to 58.7 months).KEYTRUDA (n=153) | Chemotherapy (n=154) |
---|---|
HRj=0.74; 95% CI, 0.53–1.03; Pk=0.0718 | |
Median OSNot reached (95% CI 49.2, Not reached) | Median OS36.7 months (95% CI 27.6, Not reached) |
Events Observed41%(n=62) | Events Observed51%(n=78) |
Objective Response Rate and Duration of Response In First-Line Treatment of Advanced MSI-H/dMMR CRC
Objective Response Rate (ORR)l
Response
Response
Response
Response
Duration of Response (DOR)m,n
DOR among 67 responding patients treated with KEYTRUDA and 51 responding patients treated with chemotherapyKEYTRUDA (n=67) | Chemotherapy (n=51) |
---|---|
Median DORNot reached(range: 2.3+ to 41.4+ months) | Median DOR10.6 months(range: 2.8 to 37.5+ months) |
Patient responses lasting ≥12 monthso75% | Patient responses lasting ≥12 monthso37% |
Patient responses lasting ≥24 monthso43% | Patient responses lasting ≥24 monthso18% |
+ Denotes ongoing response.
CPS = combined positive score; PD-L1 = programmed death ligand 1.
Study Design for KEYNOTE-177
The efficacy of KEYTRUDA was investigated in KEYNOTE-177, a multicenter, randomized, open-label, active-controlled trial that enrolled 307 patients with previously untreated unresectable or metastatic MSI-H or dMMR CRC. MSI or MMR tumor status was determined locally using polymerase chain reaction (PCR) or immunohistochemistry (IHC), respectively. Patients with autoimmune disease or a medical condition that required immunosuppression were ineligible. Patients were randomized (1:1) to receive KEYTRUDA 200 mg intravenously every 3 weeks or investigator’s choice of the following chemotherapy regimens given intravenously every 2 weeks: mFOLFOX6 (oxaliplatin, leucovorin, and FU) or mFOLFOX6 in combination with either bevacizumab or cetuximab: Oxaliplatin 85 mg/m2, leucovorin 400 mg/m2 (or levoleucovorin 200 mg/m2), and FU 400 mg/m2 bolus on Day 1, then FU 2400 mg/m2 over 46–48 hours. Bevacizumab 5 mg/kg on Day 1 or cetuximab 400 mg/m2 on first infusion, then 250 mg/m2 weekly; FOLFIRI (irinotecan, leucovorin, and FU) or FOLFIRI in combination with either bevacizumab or cetuximab: Irinotecan 180 mg/m2, leucovorin 400 mg/m2 (or levoleucovorin 200 mg/m2), and FU 400 mg/m2 bolus on Day 1, then FU 2400 mg/m2 over 46–48 hours. Bevacizumab 5 mg/kg on Day 1 or cetuximab 400 mg/m2 on first infusion, then 250 mg/m2 weekly. Treatment with KEYTRUDA or chemotherapy continued until RECIST v1.1-defined progression of disease as determined by the investigator or unacceptable toxicity. Patients treated with KEYTRUDA without disease progression could be treated for up to 24 months. Assessment of tumor status was performed every 9 weeks. Patients randomized to chemotherapy were offered KEYTRUDA at the time of disease progression. The main efficacy outcome measures were PFS as assessed by BICR according to RECIST v1.1, modified to follow a maximum of 10 target lesions and a maximum of 5 target lesions per organ, and OS. Additional efficacy outcome measures were ORR and DOR.
Assessment of tumor status was performed every 9 weeks.
The median duration of exposure to KEYTRUDA was 11.1 months (range: 1 day to 30.6 months).
End Points
The main efficacy outcome measures were PFS as assessed by BICR according to RECIST v1.1, modified to follow a maximum of 10 target lesions and a maximum of 5 target lesions per organ, and OS.
Additional efficacy outcome measures were ORR and DOR.
Patient Characteristics
Patients randomized to chemotherapy were offered KEYTRUDA at the time of disease progression.
Baseline Characteristics:
- Median age, years (range): 63 (24–93)
- 65 or older: 47%
- Male: 50%
- Race/ethnicity
- White: 75%
- Asian: 16%
- ECOG PS
- 0: 52%
- 1: 48%
- Received prior adjuvant or neoadjuvant chemotherapy: 27%
Among 154 patients randomized to receive chemotherapy, 143 received chemotherapy per protocol
- Chemotherapy received:
- mFOLFOX6: 56%
- FOLFIRI: 44%
- Bevacizumab + mFOLFOX6 or FOLFIRI: 70%
- Cetuximab + mFOLFOX6 or FOLFIRI: 11%