Trial results for a Phase 1 study (NCT03568058) investigating pembrolizumab in combination with a personalized vaccine for adults with advanced cancers were posted on ClinicalTrials.gov on 2026-03-24. The study reported that 0 participants across all treatment arms achieved an overall response.
Background
Pembrolizumab (Keytruda) is an anti-PD-1 antibody widely used in oncology. This study explored its use in combination with a personalized vaccine for adults with advanced cancer who were not candidates for curative therapy. The primary objective of the study was to determine the feasibility and safety of manufacturing and administering such a personalized vaccine.
Trial design
The Phase 1 study (NCT03568058) was titled "Personalized Immunotherapy in Adults With Advanced Cancers Immunotherapy in Adults With Advanced Cancers." It enrolled 25 participants diagnosed with advanced cancer. The study investigated a personalized vaccine in combination with pembrolizumab across four treatment arms:
- Arm A: Personalized Vaccine and Anti-PD-1 Administered Concurrently at the Start of Study Therapy.
- Arm B: Anti-PD-1 Antibody for 6 Weeks Followed by Personalized Vaccine Therapy.
- Arm C: Personalized Vaccine & Anti-PD-1 Administered Concurrently in a Boosted Schedule.
- Arm D: Personalized Vaccine Alone, in a Boosted Schedule at the Start of Study Therapy.
Key results
The trial reported on treatment-related adverse events and overall response across the study arms.
- For "Overall Response," 0 participants in Arm A showed a response.
- 0 participants in Arm B showed a response.
- 0 participants in Arm C showed a response.
- 0 participants in Arm D showed a response.
- Arm A (Personalized Vaccine and Anti-PD-1 Administered Concurrently) reported 19 treatment-related adverse events.
- Arm C (Personalized Vaccine & Anti-PD-1 Administered Concurrently in a Boosted Schedule) reported 103 treatment-related adverse events.
- Arm D (Personalized Vaccine Alone, in a Boosted Schedule) reported 85 treatment-related adverse events.
What this means
The results of this Phase 1 study indicate that while various personalized vaccine and pembrolizumab combinations were explored for advanced cancers, no participants demonstrated an overall response across any of the evaluated treatment arms. The reporting of treatment-related adverse events, with varying numbers across arms, provides initial safety data for these experimental combinations, which was a key objective of this feasibility study.
Source
The information for these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03568058, titled "Personalized Immunotherapy in Adults With Advanced Cancers Immunotherapy in Adults With Advanced Cancers," were posted on 2026-03-24 on clinicaltrials.gov.