A Phase 2 interventional study of Pembrolizumab in Cancer of Unknown Primary Site, sponsored by Imperial College London. Completed at 3 sites in United Kingdom. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by Imperial College London · Phase 2, Interventional, and Treatment
Abbreviated Title : CUPem Clinical Indication : A Phase II, Two-Stage, Trial of Pembrolizumab in Cancer of unknown primary Trial Type : Single Arm, non-randomised; Two-stage; Hypothesis generating Type of control : None Route of administration : IV Trial Blinding : N/A
Treatment Groups :Two cohorts:
(i) First Cohort: One or more lines of prior therapy (ii) Second Cohort: First Line untreated CUP patients Number of trial subjects : i) First Cohort: 20 ii) Second Cohort: 57 Eligibility Criteria : The Eligibility Criteria are the same as used in the A trial of chemotherapy for cancer of unknown primary (CUP-ONE) trial in the United Kingdom (UK), please see below.
Estimated recruitment period : 2 years Estimated duration of trial : 3.9 years including set up, recruitment, follow up and close down.
Duration of Participation : Cohort 1 = 6-8 months; Cohort 2 = 8-18 months Estimated average length of treatment per patient =6 months
An open label, non-randomised, single arm, sequential phase (two sequential cohorts) study, evaluating the preliminary efficacy of Pembrolizumab in Cancer of unknown Primary (CUP).
Cohort 1:
Cohort 1 will enrol a maximum of 20 patients, who have had at least one prior line / regimen of chemotherapy (at least 2 cycles) appropriate for CUP and who have not had a RECIST response to first-line chemotherapy, or are progressing after an initial response, or are treatment intolerant to first-line chemotherapy, due to unacceptable toxicity.
As soon as there has been one documented response in cohort 1, the study then proceeds to enrol cohort 2 in parallel. Cohort 2 will not be initiated, if have been no cohort 1 (0/20) patients who have benefitted and 20 cohort 1 patients have completed at least 12 weeks of therapy. Benefit for this study is defined as either a RECIST or irRECIST response; stable disease for a minimum of 12 weeks. This allows a go / no-go decision to proceed/ not proceed to enrolling cohort 2 by the trial management group
Cohort 2:
Cohort 2 will enrol a maximum of 57 patients who are chemo-naïve (first-line setting) for CUP*, with a PS 0-2. Benefit for this study is defined as either a RECIST or irRECIST response or stable disease at 12 weeks.
*Previous chemotherapy for other cancers is allowed
For both cohorts, patients will undergo screening procedures during a standard 28-days time window from initiation of the study, under standard Good Clinical Practice (GCP) and informed consent. Restaging will be performed by computerized tomography using ir-RECIST criteria at 3 months from initiation of systemic treatment and on an 8 weekly basis thereafter until radiological proven disease progression or intolerance or patient choice.
The EORTC Quality of Life Questionnaire (QLQ-C30) questionnaire (to assess the quality of life) will be done at baseline after 3 months and then at discontinuation of study treatment.
Correlative translational study samples (blood) and tissue (used for histological confirmation and to document Programmed Death-Ligand 1 (PD-L1) expression) will be collected at baseline, and blood and serum samples monthly (after an informed optional consent and banked for retrospective immune-modulating and other biomarkers for future research and analysis).
Cohort 1 - have had at least one prior line / regimen of chemotherapy appropriate for CUP (at least 2 cycles), have not had a RECIST response to first-line chemotherapy, or are progressing after an initial response, or are treatment intolerant to first-line chemotherapy, due to unacceptable toxicity.
Cohort 2 - be chemo-naive for CUP*
*Previous chemotherapy for other cancers is allowed
Adequate organ and bone marrow function (all screening tests should be performed within 10 days of treatment initiation):
Serum creatinine ≤ 1.5 x Upper Limit of Normal (ULN) or Creatinine clearance* ≥ 60 mL/min for patients with creatinine levels > 1.5 x ULN
* Creatinine clearance should be calculated per institutional standard
Female subjects of childbearing potential must be willing to use an adequate method of contraception as outlined in Section 6.9.2 - Contraception, for the course of the study through 120 days after the last dose of study medication.
Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.
Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.
Exclusion Criteria:
Has had prior chemotherapy, targeted small molecule therapy, or radiation therapy within 2 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to a previously administered agent.
All trial treatments will be administered on an outpatient basis. Pembrolizumab 200 mg will be administered as a 30 minute IV infusion every 3 weeks. Sites should make every effort to target infusion timing to be as close to 30 minutes as possible. However, given the variability of infusion pumps from site to site, a window of -5 minutes and +10 minutes is permitted (i.e., infusion time is 30 minutes: -5 min/+10 min).
Drug: Pembrolizumab
Pembrolizumab has high affinity and potent receptor blocking activity for PD-1, based on preclinical in vitro data. Pembrolizumab has an acceptable preclinical and clinical safety profile and is in clinical development as an IV immunotherapy for advanced malignancies. The PD-1 pathway represents a major immune control switch, which may be engaged by tumour cells to overcome active T-cell immune surveillance. Pembrolizumab is a potent and highly selective humanized mAb of the Immunoglobulin (IgG4)/kappa isotype designed to directly block the interaction between PD-1 and its ligands, PD-L1 and PD-L2. This blockade enhances functional activity of the target lymphocytes to facilitate tumor regression and ultimately immune rejection.
Also known as: Keytruda
Overall Response Rate (ORR) by RECIST Criteria v1.1 in the Second-line & First-line Setting.
The Response Evaluation Criteria in Solid Tumours (RECIST) criteria v1.1. classifies response based on the assessment of target and non-target lesions on CT scans as: Complete Response (CR): requires all of: * disappearance of all target and non-target lesions * pathological lymph nodes must have reduced to \<10 mm in short axis * no new lesions Partial Response (PR): requires all of: * at least 30% decrease in sum of diameters (SOD) of target lesions compared to baseline sum diameters * non-progressive disease of non-target lesions * no new lesions Progressive Disease (PD): either one of: * any new lesions * at least 20% relative and 5 mm absolute increase of SOD of target lesions compared to smallest SOD ever recorded for the patient Stable Disease (SD): not meeting criteria for PD or PR.
Time frame: From the start of the study treatment until the end of treatment, an average of 6-8 months.
Incidence Proportion of Adverse Events up to 8 Weeks After the Last Dose of Pembrolizumab in the Second Line Setting
The number of patients with any recorded adverse events (AE) defined as any untoward or unfavorable medical occurrence in a participant, including any abnormal sign (for example, abnormal physical exam or laboratory finding), symptom, or disease, temporally associated with the participant's participation in the research, whether or not considered related to the participant's participation in the trial. The incidence proportion or cumulative incidence is the percentage (%) of patients developing new AEs out of the total number at risk followed during that time frame.
Time frame: 6-8 months, based on average length of treatment per patient
Incidence of Adverse Events up to 8 Weeks After the Last Dose of Pembrolizumab in Performance Status 2 (PS2) Patients in Any Setting
The number of patients whose Performance Status was equal to two at baseline, with any recorded adverse events (AE) defined as any untoward or unfavorable medical occurrence in a participant, including any abnormal sign (for example, abnormal physical exam or laboratory finding), symptom, or disease, temporally associated with the participant's participation in the research, whether or not considered related to the participant's participation in the trial. The incidence proportion or cumulative incidence is the percentage (%) of patients developing new AEs out of the total number at risk followed during that time frame.
Time frame: 6-8 months (based on average length of treatment per patient)
Identification of Potential Genomic Biomarkers Predictive of Immune Response to Pembrolizumab
This would be a retrospective analysis of blood samples collected for future research purposes only. Research bloods will be used to examine DNA and measure various blood biomarkers. These biomarkers may predict possible response to study treatment. As these samples are being taken before, during and after treatment, they will help us understand how the study treatments work. This will also enable us to learn whether or not the treatments have the desired effect, and to understand if these effects may be beneficial for the treatment of cancer of unknown primary (CUP). This information may also be used to develop and test other new treatments in the future. The panel of potential biomarkers against which the blood plasma will be tested has not been established yet. Information gained from this research component is not directly beneficial to patients taking part in this clinical trial.
Time frame: 12 months (post study completion)
| Milestone | Pembrolizumab |
|---|---|
| Started | 35 |
| Completed | 35 |
| Not completed | 0 |
The Response Evaluation Criteria in Solid Tumours (RECIST) criteria v1.1. classifies response based on the assessment of target and non-target lesions on CT scans as: Complete Response (CR): requires all of: * disappearance of all target and non-target lesions * pathological lymph nodes must have reduced to \<10 mm in short axis * no new lesions Partial Response (PR): requires all of: * at least 30% decrease in sum of diameters (SOD) of target lesions compared to baseline sum diameters * non-progressive disease of non-target lesions * no new lesions Progressive Disease (PD): either one of: * any new lesions * at least 20% relative and 5 mm absolute increase of SOD of target lesions compared to smallest SOD ever recorded for the patient Stable Disease (SD): not meeting criteria for PD or PR.
| Participants | Pembrolizumab |
|---|---|
| Complete Response (CR) | 0 |
| Partial Response (PR) | 4 |
| Stable Disease (SD) | 9 |
| Progressive Disease (PD) | 13 |
| Not Evaluable (NE) | 9 |
The number of patients with any recorded adverse events (AE) defined as any untoward or unfavorable medical occurrence in a participant, including any abnormal sign (for example, abnormal physical exam or laboratory finding), symptom, or disease, temporally associated with the participant's participation in the research, whether or not considered related to the participant's participation in the trial. The incidence proportion or cumulative incidence is the percentage (%) of patients developing new AEs out of the total number at risk followed during that time frame.
| Participants | Pembrolizumab |
|---|---|
| Incidence Proportion of Adverse Events up to 8 Weeks After the Last Dose of Pembrolizumab in the Second Line Setting | 34 |
The number of patients whose Performance Status was equal to two at baseline, with any recorded adverse events (AE) defined as any untoward or unfavorable medical occurrence in a participant, including any abnormal sign (for example, abnormal physical exam or laboratory finding), symptom, or disease, temporally associated with the participant's participation in the research, whether or not considered related to the participant's participation in the trial. The incidence proportion or cumulative incidence is the percentage (%) of patients developing new AEs out of the total number at risk followed during that time frame.
| Participants | Pembrolizumab |
|---|---|
| Incidence of Adverse Events up to 8 Weeks After the Last Dose of Pembrolizumab in Performance Status 2 (PS2) Patients in Any Setting | 5 |
This would be a retrospective analysis of blood samples collected for future research purposes only. Research bloods will be used to examine DNA and measure various blood biomarkers. These biomarkers may predict possible response to study treatment. As these samples are being taken before, during and after treatment, they will help us understand how the study treatments work. This will also enable us to learn whether or not the treatments have the desired effect, and to understand if these effects may be beneficial for the treatment of cancer of unknown primary (CUP). This information may also be used to develop and test other new treatments in the future. The panel of potential biomarkers against which the blood plasma will be tested has not been established yet. Information gained from this research component is not directly beneficial to patients taking part in this clinical trial.
Results for this outcome have not been posted.
Collected over From the start of the study treatment until the end of treatment, an average of 6-8 months.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Pembrolizumab | 27/35 (77.1%) | 20/35 (57.1%) | 15/35 (42.9%) |
| Event | Pembrolizumab |
|---|---|
| Alanine aminotransferase increasedInvestigations | 2/35 |
| DiarrhoeaGastrointestinal disorders | 2/35 |
| Abdominal painGastrointestinal disorders | 2/35 |
| HyponatraemiaMetabolism and nutrition disorders | 1/35 |
| ConfusionPsychiatric disorders | 1/35 |
| Pericardial effusionCardiac disorders | 1/35 |
| Peripheral swellingCardiac disorders | 1/35 |
| HypoaesthesiaNervous system disorders | 1/35 |
| Haemoglobin decreasedInvestigations | 1/35 |
| Pleural effusionRespiratory, thoracic and mediastinal disorders | 1/35 |
| Event | Pembrolizumab |
|---|---|
| FatigueGeneral disorders | 14/35 |
| Abdominal painGastrointestinal disorders | 9/35 |
| ConstipationGastrointestinal disorders | 8/35 |
| VomitingGastrointestinal disorders | 8/35 |
| Decreased appetiteMetabolism and nutrition disorders | 6/35 |
| HypothyroidismEndocrine disorders | 6/35 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 5/35 |
| NauseaGastrointestinal disorders | 5/35 |
| PyrexiaGeneral disorders | 5/35 |
| DyspnoeaRespiratory, thoracic and mediastinal disorders | 4/35 |
| Age, Continuous(years) | Pembrolizumab |
|---|---|
| Median | 58 (50 to 66) |
| Sex: Female, Male(Participants) | Pembrolizumab |
|---|---|
| Female | 21 |
| Male | 14 |
| Ethnicity (NIH/OMB)(Participants) | Pembrolizumab |
|---|---|
| Hispanic or Latino | 0 |
| Not Hispanic or Latino | 33 |
| Unknown or Not Reported | 2 |
| Region of Enrollment(participants) | Pembrolizumab |
|---|---|
| United Kingdom | 35 |
| Histology(Participants) | Pembrolizumab |
|---|---|
| Poorly differentiated adenocarcinoma or carcinoma | 11 |
| Well or Moderately Differentiated Adenocarcinoma | 9 |
| Undifferentiated Adenocarcinoma or Carcinoma | 8 |
| Squamous cell carcinoma | 7 |
| Eastern Cooperative Oncology Group (ECOG) Performance Status(Participants) | Pembrolizumab |
|---|---|
| 0 to 1 | 30 |
| 2 | 5 |
| EORTC QLQ-C30 Summary Score(units on a scale) | Pembrolizumab |
|---|---|
| Mean | 70 ± 18 |
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Imperial College London