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Active, not recruitingNCT04336241Updated Feb 27, 2026

Study of RP2 Monotherapy and RP2 in Combination With Nivolumab in Patients With Solid Tumors

A Phase 1 interventional study of RP2 and nivolumab in Cancer, sponsored by Replimune, Inc.. Active, not recruiting at 6 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-27.

Sponsored by Replimune, Inc. · Phase 1, Interventional, and Treatment

From the registry’s dates

  • Registered 5 months after the study started (first participant enrolled Oct 2019, registered Mar 2020).
Phase
Phase 1
Study type
Interventional
Enrollment
36
Allocation
Non-randomized
Ages
18 Years and older
Sex
All
01

Study summary

RP2-001-18 is a Phase 1, multicenter, open label, single agent dose escalation and combination treatment study of RP2 in adult subjects with advanced solid tumors, to determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D), as well as to evaluate preliminary efficacy.

Read the detailed description

RP2 is a genetically modified herpes simplex type 1 virus (HSV-1) that expresses an anti-CTLA-4 antibody and is designed to directly destroy tumors and to generate an anti-tumor immune response. This is a Phase 1, multicenter, open label, dose escalation and expansion, first-in-human (FIH) clinical study to evaluate the safety and tolerability, biodistribution, shedding, and preliminary efficacy of RP2 alone and in combination with nivolumab in adult subjects with advanced solid tumors.

The study will be conducted in two parts. The first part of the study is an open-label, dose escalation FIH Phase 1 study to assess the safety and tolerability of RP2 and to determine the recommended Phase 2 dose (RP2D) to be used in the second part of the study. The second part of the study is an open label design to further investigate safety of RP2 in combination with nivolumab. It will also assess the biological activity of multiple doses of RP2 in combination with nivolumab. An expansion to the second part of the study will include enrolment of a further 30 patients on RP2 in combination with nivolumab.

Following completion of the expansion in part 2, part 3 will enroll a further 15 patients on RP3 monotherapy.

The expansion to part 2 and part 3 will focus on patients with advanced or metastatic uveal melanoma, lung cancer, breast cancer or GI cancers and patients with liver metastasis.

02

Conditions studied

  • Cancer

Keywords

  • Uveal Melanoma
  • Gastrointestinal Cancers
  • Lung Cancer
  • Breast Cancer
03

In context

Neoplasms

9,359 studies on the registry are indexed under Neoplasms; 2,486 are open to participants now.

This study's planned enrollment of 36 is below the median of 50 across 7,250 interventional studies indexed under Neoplasms.

Browse Neoplasms studies →

Lead sponsor

Replimune, Inc. is the lead sponsor of 10 studies on the registry; 4 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Willing and able to participate and comply with all trial requirements and able to provide signed and dated informed consent prior to initiation of any trial procedures
  • Male or Female ≥ 18 years of age
  • Patients with advanced or metastatic non-neurological solid tumors, who have progressed on standard therapy or cannot tolerate standard therapy, or for which there is no standard therapy preferred to enrolment in a clinical trial
  • Consent to provide archival tumour biopsy samples within 6 months, or a fresh tumour biopsy is needed. Patients must also consent to provide on-treatment biopsies as per protocol
  • At least one measurable and injectable tumor of ≥ 1 cm in longest diameter (or shorter diameter for lymph nodes).
  • Women of child-bearing potential (WOCBP) must have a negative urine pregnancy test at screening and a negative urine pregnancy test prior to administration of each dose of RP2 or nivolumab
  • WOCBP must agree to use adequate birth control throughout their participation and for 3 months after RP2 alone and 5 months after nivolumab last study treatment
  • Males with partners of child-bearing potential must agree to use adequate birth control throughout their participation and for 3 months for RP2 alone and 7 months after nivolumab last study treatment
  • Have laboratory values (obtained ≤ 28 days prior to first infusion day) in accordance with the study protocol
  • Have an Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1

Cohort 2a only:

  • Baseline ECG that does not show abnormalities according to the protocol
  • Baseline troponin \< 0.06 ng/mL
  • Baseline oxygen saturation levels that do not show abnormalities according to the protocol

Cohort 2b and Part 3 only:

  • Patients in Cohort 2b should have histologically or cytologically confirmed diagnosis of advanced or metastatic uveal melanoma, lung cancer, breast cancer, or gastrointestinal cancers (including but not limited to colorectal cancer [CRC] [microsatellite stable], gastric cancer, gastroesophageal junction cancer, and oesophageal cancer) (n=30)
  • Patients with HCC and a diagnosis of hepatitis B must be off antiviral therapy for at least 4 weeks prior to enrollment.
  • Patients with acute or chronic hepatitis B or C must be expected to not require antiviral therapy during the RP2 treatment period.
  • Patients with HCC who have evidence of acute or chronic hepatitis C infection must have completed treatment for hepatitis C at least 1 month prior to study enrollment
  • Patients in Part 3 should have solid tumours (excluding skin cancers) that the investigator deems suitable for RP2 monotherapy, including at least 10 patients with liver metastases from prevalent tumour types (e.g. lung, breast [including recurrent chest wall], and gastrointestinal cancers [colorectal, gastric, and oesophageal cancers]) (n=15)
  • Patient has progressed during or after one to three prior systemic anticancer therapies for advanced or metastatic disease or during or within six months of receiving adjuvant therapy. Patients who, in the opinion of the investigator, are deemed not appropriate candidates for standard-of-care systemic anticancer therapy for advanced or metastatic disease, or who, after documented consultation with their treating physician, refuse standard-of-care systemic anticancer therapy may be eligible after discussion with the medical monitor

Exclusion criteria

Exclusion Criteria:

  • Prior treatment with an oncolytic virus therapy
  • History of viral infections according to the protocol
  • Systemic infection requiring IV antibiotics within 14 days prior to dosing
  • Prior complications with herpes infections
  • Chronic use of anti-virals
  • Systemic therapies for cancer within five half-lives or 4 weeks of first dose; whichever is shorter
  • Conditions that require certain doses of steroids (some doses and types will be permitted)
  • Known active brain metastases - previously treated brain metastases may be permitted
  • Major surgery ≤ 2 weeks prior to starting study drug
  • Prior malignancy active with the previous 3 years; except for locally curable cancers that have apparently been cured
  • Female who has a positive urine pregnancy test or is breast-feeding or planning to become pregnant during study treatment and 90 days for RP2 alone or 5 months for RP2 and nivolumab after the last dose of treatment
  • Participation in another clinical study within 4 weeks prior to the first dose
  • History of myocarditis or congestive heart failure (as defined by the New York Heart Association Functional Classification III or IV), or unstable angina, serious uncontrolled cardiac arrhythmia, uncontrolled infection, or myocardial infarction within 6 months of randomization

    • History of allergy or sensitivity to study drug components
    • Has known psychiatric or substance abuse disorders that would interfere with cooperating with the requirements of the study

Part 2 patients only:

  • Participants with history of life-threatening toxicity related to prior immune therapy except those that are likely to re-occur with standard countermeasures
  • Treatment with botanical preparations within 2 weeks prior to treatment
  • Certain autoimmune diseases, some types will be permitted
  • History of interstitial lung disease
  • Severe hypersensitivity to another monoclonal antibody
  • Has received radiotherapy within 2 weeks of start of study treatment
  • Has received a live vaccine within 28 days prior to first dose of study drug
  • History of non-infectious pneumonitis
  • History or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the study
  • Other serious or uncontrolled medical disorders

Cohort 2b and Part 3 (only for the subset of patients with liver metastases suitable and intended for injection)

  • Presence of liver metastases that are estimated to invade more than one-third of the liver
  • Macroscopic intravascular invasion into the main portal vein, hepatic vein or vena cava
  • Significant bleeding event within the last 12 months that places the patient at risk for intrahepatic intratumoral injection procedure based on investigator assessment
  • Prior chemoembolization, radioembolization, or other locoregional liver-directed procedures to the lesion selected for intratumoral injection
05

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
36 participants (estimated)

Study arms

  • Experimental
    Dose escalation of RP2 - superficial tumors

    Dose escalation of RP2 alone in 3 cohorts with IT injections in superficial tumors.

    Biological: RP2

  • Experimental
    Dose escalation of RP2 - deep/visceral tumors

    Dose escalation of RP2 alone in 3 cohorts with imaging guided IT injections in deep/visceral tumors.

    Biological: RP2

  • Experimental
    Dose expansion of RP2 and nivolumab - superficial tumors

    Doses of RP2 (IT) in superficial tumors with nivolumab (IV).

    Biological: RP2 · Biological: nivolumab

  • Experimental
    Dose expansion of RP2 and nivolumab - deep/visceral tumors

    Imaging guided doses of RP2 (IT) in deep/visceral tumors.

    Biological: RP2 · Biological: nivolumab

  • Experimental
    Seronegative cohort

    Doses of RP2 (IT) in HSV seronegative participants.

    Biological: RP2

Interventions

  • BiologicalRP2

    Genetically modified herpes simplex type 1 virus for tumor lysis and immune stimulation

  • Biologicalnivolumab

    Programmed death receptor (PD-1) blocking antibody

    Also known as: Opdivo

06

What researchers measure

Primary outcomes

  1. Percentage of adverse events (AEs)

    Percentage of subjects with AEs

    Time frame: From Day 1 up to 60 days after last dose

  2. Percentage of serious adverse events (SAEs)

    Percentage of subjects with SAEs

    Time frame: From Day 1 up to 60 days after last dose

  3. Percentage of dose limiting toxicities (DLTs)

    Percentage of subjects with DLTs

    Time frame: From Day 1 up to 30 days after last dose.

  4. Percentage of treatment emergent adverse events (TEAEs)

    Percentage of subjects with TEAEs

    Time frame: From Day 1 up to 60 days after last dose.

  5. Percentage of TEAEs ≥ Grade 3

    Percentage of subjects with TEAEs ≥ Grade 3

    Time frame: From Day 1 up to 60 days after last dose.

  6. Percentage of events requiring withdrawal

    Percentage of subjects experiencing events requiring withdrawal from treatment.

    Time frame: From Day 1 up to last dose (up to 8 weeks for dose escalation phase and up to 2 years for expansion phase)).

  7. Maximum tolerated dose (MTD) of RP2

    MTD on the safety and response data collected during the dose escalation phase (Part 1).

    Time frame: 7 months

  8. Recommended Phase 2 dose (RP2D) of RP2

    RP2D of RP2 based on the safety and response data collected during the dose escalation phase (Part 1).

    Time frame: 7 months

Secondary outcomes

  1. Percentage of biologic activity

    Percentage of subjects with biological activity determined by tumor biopsies and biomarker data

    Time frame: 20 weeks

  2. Percentage of subjects with detectable RP2

    Data gathered from blood, urine, swabs of injection site, dressings, and oral mucosa to determine the shedding and biodistribution of RP2.

    Time frame: 20 weeks

  3. Change in HSV-1 antibody levels

    Change in HSV-1 antibody levels during treatment compared to baseline

    Time frame: From Day 1 up to last dose (up to 4 months for dose escalation phase and up to 5.5 months for expansion phase)).

  4. Percentage of overall response rate (ORR)

    Percentage of ORR.

    Time frame: 3 years

  5. Median duration of response

    Median duration of response of subjects

    Time frame: 3 years

  6. Median progression-free survival

    Median duration of progression-free survival of subjects

    Time frame: 3 years

  7. Median overall survival

    Median overall survival rate of subjects

    Time frame: 3 years

  8. Percentage of complete response (CR)

    Percentage of subjects with a CR

    Time frame: From Day 1 up to last dose (up to 8 weeks for escalation phase and up to 2 years for expansion phase).

  9. Percentage of partial response (PR)

    Percentage of subjects with a PR

    Time frame: From Day 1 up to last dose (up to 8 weeks for escalation phase and up to 2 years for expansion phase).

  10. Percentage of stable disease (SD)

    Percentage of subjects with SD

    Time frame: From Day 1 up to last dose (up to 8 weeks for escalation phase and up to 2 years for expansion phase).

07

Study locations

6 sites
  • Hospital Universitario d'Hebron
    Barcelona, 119 08035, Spain
  • Hospital Universitario HM Sanchinarro
    Madrid, 10 28050, Spain
  • Hospital Clinico de Valencia
    Valencia, 46010, Spain
  • The Clatterbridge Cancer Centre NHS Foundation Trust
    Bebington, Merseyside CH63 4JY, United Kingdom
  • The Royal Marsden NHS Foundation Trust
    London, SW3 6JJ, United Kingdom
  • Churchill Hospital
    Oxford, OX3 9DU, United Kingdom
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 27, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT04336241
Lead sponsor
Replimune, Inc.
Responsible party
Sponsor
First posted
Apr 7, 2020
Start date
Oct 17, 2019
Primary completion
Oct 31, 2026 (estimated)
Completion
Oct 31, 2026 (estimated)
Last update
Feb 27, 2026

Study contacts

Gary Vanasse, MD
study director · Replimune, Inc.

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.

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