Pembrolizumab and Palliative Radiotherapy in Lung (PEAR)

April 1, 2026 updated by: Royal Marsden NHS Foundation Trust

Phase I Dose Escalation of pAlliative Radiotherapy With Anti-PD1 Antibody Pembrolizumab in Thoracic Tumours

Lung cancer is the second most common cancer in the UK with around 43,500 new patients diagnosed each year. About 69% of patients are diagnosed with advanced stage disease and at present these patients would be expected to survive for less than 12 months. These statistics therefore show the need for the development of new effective drugs in the treatment of advanced Lung cancer.

Recent trial results have shown the efficacy of immunotherapy in treating several types of tumours including lung cancer. These tumours are known to express a high level of a glycoprotein called PDL1 which is a component of the PD1 pathway. In cancer the PD1 pathway can be hijacked by tumours leading to the immune system being suppressed. The aim of the new drug Pembrolizumab is to restart the PD1 pathway and use the immune system to help fight the cancer cells. Radiotherapy has also been shown to cause cancer to increase production of the proteins that can block the immune system. Therefore it has been proposed that combine of new immunotherapy agent such as pembrolizumab and radiotherapy in the treatment of lung cancer will allow more cancer cells to be killed through the immune system.

The purpose of this study is to see if pembrolizumab can safety be combined with standard palliative radiotherapy in patients with lung cancer. In addition once the patients have completed their course of radiotherapy they will remain on pembrolizumab alone and the study will look at how well this treatment regimen can control the growth of the cancer.

Study Overview

Status

Completed

Conditions

Detailed Description

  1. Risk and burden for patients

    Patients in the first part of this study have cancer that is no longer responding to standard anticancer drug treatments.The phase 1 nature of this study means that the trial intervention may not have any additional benefit for patients who take part in the study.

    The study itself carries a number of potential burdens:

    • Study drug and radiotherapy:

    Although the study drug safety effects have previously been assessed in NSCLC the side effects caused by the addition of radiotherapy is unconfirmed. These risks will be managed as much as possible by cautious dose escalation: as with all phase 1 studies, the data from each cohort will be reviewed by a safety review committee before deciding whether to increase the dose for subsequent cohorts.

    Participants will be reviewed regularly by experienced clinicians while having the study treatment. Comprehensive assessments for safety will be carried out.

    • Burden of frequent hospital visits and tests:

    Participants in this study must attend hospital frequently, particularly at the start of the study, for safety reasons to check for any toxicity of the study treatment. Blood tests, clinical examination, urine tests, haematology, bio chemistry and lung function tests are part of the safety assessment. Additionally, for research purposes some participants may be asked to have additional blood taken, these will not be mandatory for entry into the study.

  2. Recruitment

Participants will be offered information about this study by their clinical teams if they are considered to meet the entry criteria (with regard to advanced disease without therapeutic option, suitable performance status) and express interest in taking part in an experimental study. It will be made clear that the study is experimental in nature and that there will not necessarily be a therapeutic benefit from taking part in the study. It will also be made clear that, should patients decide not to take part their future care will not be affected. Patients will be given sufficient time and information to make an informed decision about entering the trial, all patients entering the trial will give written informed consent.

4. Confidentiality

Patients will be linked to a unique identifier the code for which will be held on a password protected database held only by the study team. This study will run at the Royal Marsden Hospital Only. Research blood and tumour data will be analysed by a team at the Institute of cancer Research. Sample processing will take place using the trial ID only. No other patient identifiable information will be available on study samples. Investigators will have access to patient identifiable information on password protected NHS hospital notes and databases only.

5. Conflict of Interest

Patients may be recruited to the study by those involved in their prior clinical care. The investigators do not expect conflict of interest between research and healthcare duties for a number of reasons: patients must give their full informed consent before entering the study, specifically regarding the unknown efficacy of the study drug. Those patients who do not continue in the study will maintain a relationship with the clinical team if required for symptom control. At the end of the study, patients will be able to access the results if they wish, through the Royal Marsden Website. They will also be sent a written summary of the results if they indicate this.

6. Use of tissue samples in future research

If participants give their consent, any leftover blood or tissue samples which are not required for this study will be stored for future unspecified research in line with the human tissue act regulations. Access and use of samples for research purposes will require appropriate ethical approval. Future researchers will not be able to identify individual patients from their biobank data, demographic and clinical information will be available.

Study Type

Interventional

Enrollment (Actual)

24

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • London, United Kingdom, SW3 6JJ
        • NIHR Biomedical Research Centre at RM and ICR (https://www.cancerbrc.org/)
      • Sutton, United Kingdom, SM2 5PT
        • NIHR Biomedical Research Centre at RM and ICR (https://www.cancerbrc.org/)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Be willing and able to provide written informed consent for the trial.
  2. Have measurable disease based on RECIST 1.1.
  3. Histologically verified NSCLC including squamous cell carcinoma, adenocarcinoma, adenosquamous or large cell anaplastic carcinoma; requiring palliative radiotherapy for which no curative therapy exists will be recruited into the trial.
  4. Patients are permitted to have extrathoracic disease which will not be encompassed in the radiotherapy field. This disease will be assessed for abscopal response
  5. Ability to tolerate a course of palliative radiotherapy to the lung.
  6. Have provided tissue from an archival tissue sample or newly obtained core or excisional biopsy of a tumour lesion.
  7. Have a performance status of 0-2 on the ECOG Performance Scale.
  8. Demonstrate adequate organ function, all screening labs should be performed within 10 days of confirmation of eligibility.
  9. Patient's lung function tests at baseline should have an FEV1 > 0.8L or > 30%.
  10. See protocol section.

Exclusion Criteria:

  1. Is currently participating in or has participated in a study of an investigational agent or using an investigational device within 4 weeks of the first dose of treatment.
  2. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of trial treatment.
  3. Has had a prior monoclonal antibody within 4 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to agents administered more than 4 weeks earlier.
  4. Previous radiotherapy to the lung
  5. Has had prior chemotherapy, targeted small molecule therapy, or radiation therapy within 4 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.

    Note: Patients with ≤ Grade 2 neuropathy are an exception to this criterion and may qualify for the study.

    Note: If patient received major surgery, they must have recovered adequately from the toxicity and/or complications from the intervention prior to starting therapy.

  6. Has a known additional malignancy that is progressing or requires active treatment. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy.
  7. Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Patients with previously treated brain metastases may participate provided they are stable (without evidence of progression by imaging for at least four weeks prior to the first dose of trial treatment and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroids for at least 7 days prior to trial treatment.
  8. Has an active autoimmune disease requiring systemic treatment within the past 3 months or a documented history of clinically severe autoimmune disease, or a syndrome that requires systemic steroids or immunosuppressive agents. Patients with vitiligo or resolved childhood asthma/atopy would be an exception to this rule. Patients that require the use of bronchodilators or local steroid injections would not be excluded from the study. Patients with hypothyroidism stable on hormone replacement or Sjorgen's syndrome will not be excluded from the study.
  9. Has evidence of interstitial lung disease or active, noninfectious pneumonitis.
  10. Has received prior therapy with an antiPD1, antiPDL1, antiPDL2, antiCD137, or anti Cytotoxic T-lymphocyte associated antigen4 (CTLA4) antibody (including ipilimumab or any other antibody or drug specifically targeting T-cell costimulation or checkpoint pathways).
  11. See protocol section.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Low Dose Radiotherapy Arm
Pembrolizumab and radiotherapy
Radiotherapy - Standard Treatment
Pembrolizumab - Trial Treatment
Other Names:
  • MK-3475/pembrolizumab (KEYTRUDA®)
Experimental: High Dose Radiotherapy Arm
Pembrolizumab and radiotherapy
Radiotherapy - Standard Treatment
Pembrolizumab - Trial Treatment
Other Names:
  • MK-3475/pembrolizumab (KEYTRUDA®)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Toxicity Rate of Dose Limiting Toxicities (DLTs) Assessed by CTCAEv4
Time Frame: 2 months following the final fraction of RT

DLT period is defined as the interval of 2 months following the final fraction of RT (at the beginning of cycle 4), using CTCAE v4.0 for acute toxicity. For this study a DLT would be regarded as any event of pneumonitis at ≥ grade 2.

DLTs were collected to determine the Maximum-Tolerated Dose (MTD). The toxicity rate will be stated as the proportion of patients who have had a DLT calculated with a 95% confidence interval.

2 months following the final fraction of RT
Maximum Tolerated Dose (MTD) of Pembrolizumab That Can be Safely Combined With Radiotherapy (RT) in the Absence of Dose Limiting Toxicity (DLT) Assessed by CTCAEv4
Time Frame: 2 months following the final fraction of RT
MTD was determined by testing increasing doses of pembrolizumab (100mg / 200mg) and low/high doses of RT. MTD reflects the highest dose in the absence of a DLT. The DLT period is defined as the interval of 2 months following the final fraction of RT (at the beginning of cycle 4), using CTCAE v4.0 for acute toxicity. For this study a DLT would be regarded as any event of pneumonitis at ≥ grade 2.
2 months following the final fraction of RT

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression Free Survival at 6 and 12 Months
Time Frame: 6 and 12 months
Progression-free survival (PFS) will be measured from the start of RT until radiological or clinical evidence of progression or else death from any cause. Any progression free surviving patients will be censored at last follow-up date. Using Kaplan-Meier methods, PFS rates at 6 months and 1 year will be reported with 95% confidence intervals.
6 and 12 months
Overall Survival at 6 and 12 Months
Time Frame: 6 and 12 months
Overall survival (OS) will be measured from the start of RT until death from any cause; any surviving patients will be censored at last follow-up date. Using Kaplan-Meier methods, survival rates at 6 months and 1 year will be reported with 95% confidence intervals.
6 and 12 months
PFS at 6 and 12 Months by PDL-1 Status (Strong vs Non-strong)
Time Frame: 6 and 12 months
PD-L1 staining is referred to as tumour proportion score, reported as a percentage from 0-100%. A PDL1 strong population will be those who have a tumour proportion score of >/=50%. Using Kaplan-Meier methods, survival rates at 6 months and 1 year for each PDL1 subgroup will be reported with 95% confidence intervals.
6 and 12 months
OS at 6 and 12 Months by PDL-1 Status (Strong vs Non-strong)
Time Frame: 6 and 12 months
PD-L1 staining is referred to as tumour proportion score, reported as a percentage from 0-100%. A PDL1 strong population will be those who have a tumour proportion score of >/=50%. Using Kaplan-Meier methods, survival rates at 6 months and 1 year for each PDL1 subgroup will be reported with 95% confidence intervals.
6 and 12 months
Progression Free Survival (PFS2) From Date of First Response at 6 and 12 Months
Time Frame: 6 and 12 months
Progression-free survival (PFS2) will be measured from the first response (defined as CR or PR or SD using RECIST v1.1) until radiological or clinical evidence of progression or else death from any cause (also known as "duration of clinical benefit"). Any patients not experiencing a response will not be included, and any progression free surviving patients will be censored at last follow-up date. Using Kaplan-Meier methods, PFS2 rates at 6 months and 1 year will be reported with 95% confidence intervals.
6 and 12 months
PFS2 (From Date of First Response) by Histological Sub-types (Squamous vs Non-squamous)
Time Frame: 6 and 12 months
Progression-free survival (PFS2) will be measured from the first response (defined as CR or PR or SD using RECIST v1.1) until radiological or clinical evidence of progression or else death from any cause (also known as "duration of clinical benefit"). Any patients not experiencing a response will not be included, and any progression free surviving patients will be censored at last follow-up date. Using Kaplan-Meier methods, PFS2 rates at 6 months and 1 year for each histological subgroup (squamous vs non-squamous) will be reported with 95% confidence intervals.
6 and 12 months
Oesophagitis Rates Assessed at Two Months After the Last Fraction of RT Has Been Administered
Time Frame: two months after the last fraction of RT
Oesophagitis events will be determined by CTCAE v4.0. Proportion of patients with oesophagitis grade 2+ will be summarised with associated 95% confidence interval.
two months after the last fraction of RT

Other Outcome Measures

Outcome Measure
Time Frame
Identify biomarkers and correlate with clinical benefit, as defined by RECIST v1.1
Time Frame: through study completion (24 months)
through study completion (24 months)
Assessing individual lesion response (CR/PR/PD/SD) determined by RECIST v1.1 to evaluate the abscopal effect between pembrolizumab and RT
Time Frame: cycle 2 (week 8/9) and cycle 5 (week 17/18)
cycle 2 (week 8/9) and cycle 5 (week 17/18)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Director: Dr Merina Ahmed, Consultant Clinical Oncologist

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 24, 2016

Primary Completion (Actual)

August 20, 2021

Study Completion (Actual)

August 20, 2021

Study Registration Dates

First Submitted

October 13, 2015

First Submitted That Met QC Criteria

October 23, 2015

First Posted (Estimated)

October 27, 2015

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 1, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • CCR 4282

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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