Melanoma Stage IIIPhase 2INFLECTION-003NCT07565285
The Efficacy and Safety of PRTX007-003 Combined With Pembrolizumab in Resectable Stage III Melanoma
A Phase 2 study testing PRTX007 and Pembrolizumab in people with Melanoma Stage III, run by Primmune Therapeutics, Inc. at 7 sites in Australia.
Trial summary
This Phase 2, multi-center, single-arm study evaluates the safety, tolerability, and activity of neoadjuvant PRTX007 in combination with pembrolizumab in participants with resectable Stage III melanoma. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Melanoma Stage III
- What is being tested?
- PRTX007 and Pembrolizumab
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 7 sitesAustralia
- Study dates
- 1 Jul 2026to Jun 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 years or older
- Histologically confirmed, resectable Stage III cutaneous melanoma.
- Candidate for curative-intent surgical resection
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
- Adequate organ function
- Able to provide written informed consent
Who cannot join
- Prior systemic therapy for melanoma, including immunotherapy
- Uveal melanoma or mucosal melanoma.
- Active autoimmune disease requiring systemic treatment
- Primary immunodeficiency or use of systemic immunosuppressive therapy
- Women who are pregnant or breastfeeding
- Recent treatment with another investigational therapy
- Any condition that, in the opinion of the investigator, would interfere with study participation or safety
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
Australia7 sites, 7 recruiting
- Not yet recruiting
Cairns And Hinterland Hospital And Health Service
Cairns, Queensland, 4870
- Not yet recruiting
Gallipoli Medical Research
Greenslopes, Queensland, 4120
- Recruiting
Peter MacCallum Cancer Centre
Melbourne, Victoria, 3000
- Recruiting
One Clinical Research Pty Ltd
Nedlands, Western Australia, 6009
- Not yet recruiting
Sir Charles Gairdner Hospital
Nedlands, Western Australia, 6009
- Recruiting
Calvary Mater Newcastle
Waratah, New South Wales, 2298
- Not yet recruiting
Princess Alexandra Hospital
Woolloongabba, Queensland, 4102
About this study
Official title: A Phase 2 Study to Investigate the Activity of Neoadjuvant PRTX007 Combined With Pembrolizumab in Participants With Stage III Melanoma (INFLECTION-003)
This Phase 2, multi-center, single-arm study evaluates the safety, tolerability, and activity of neoadjuvant PRTX007 in combination with pembrolizumab in participants with resectable Stage III melanoma. Neoadjuvant immunotherapy has demonstrated improved clinical outcomes compared with adjuvant-only approaches, but there remains a need to enhance pathologic response rates without significant added toxicity.
Participants will receive oral PRTX007, a Toll-like receptor 7 (TLR7) agonist prodrug, administered in combination with intravenous pembrolizumab prior to surgical resection. The primary objective is to determine the major pathologic response (MPR) rate following neoadjuvant therapy. Secondary objectives include evaluation of safety, pathologic complete response, event-free survival, overall survival, pharmacokinetics, and immune-related biomarkers.
This study aims to determine whether the addition of PRTX007 to pembrolizumab improves antitumor immune responses and clinical outcomes in patients with Stage III melanoma.
Read the detailed description
This study investigates whether combining the TLR7 agonist PRTX007 with pembrolizumab enhances immune-mediated tumor response in the neoadjuvant setting for Stage III melanoma, with the goal of improving pathologic response rates and clinical outcomes while maintaining an acceptable safety profile.
Design This is a Phase 2, multi-center, open-label, single-arm study conducted in Australia. The study will enroll approximately 48 participants with resectable Stage III melanoma.
The study consists of two parts:
- Part A: 24 participants will be enrolled, including an initial dose-escalation safety run-in using a 3+3 design to evaluate tolerability and dose-limiting toxicities.
- Part B: An additional 24 participants will be enrolled if sufficient activity is observed in Part A.
Treatment Plan
Participants will receive neoadjuvant therapy consisting of:
- PRTX007: Oral administration for 3 days on and 4 days off per week for 9 cycles (7-day cycles)
- Pembrolizumab: 200 mg intravenous infusion every 3 weeks for 3 cycles Following completion of neoadjuvant therapy, participants will undergo definitive surgical resection.
Post-surgical treatment will be response-adapted:
- Participants achieving MPR may receive observation or pembrolizumab alone
- Participants without MPR will receive adjuvant PRTX007 in combination with pembrolizumab
- Conditions
- Melanoma Stage III
- Being tested
- PRTX007, Pembrolizumab
- Medical subject headings
- Melanoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PRTX007Drug
PRTX007 is an orally administered prodrug of PRX034, a Toll-like receptor 7 (TLR7) agonist designed to activate innate and adaptive immune responses.
NEOADJUVANT REGIMEN
- 600 mg orally once daily (safety run-in participants) or
- 750 mg orally once daily (subsequent participants)
- Administered 3 days on, 4 days off (7-day cycle)
- Total of 9 cycles (9 weeks)
ADJUVANT REGIMEN (IF NO MPR)
- 750 mg orally once daily
- Administered 3 days on, 4 days off
- Total of 12 cycles (12 weeks)
PembrolizumabDrug
Pembrolizumab is a programmed cell death protein-1 (PD-1) blocking antibody administered by intravenous infusion
NEOADJUVANT REGIMEN
- 200 mg IV every 3 weeks (Q3W)
- Total of 3 cycles (9 weeks)
ADJUVANT REGIMEN
- 400 mg IV every 6 weeks (Q6W) for 7 cycles OR
- 200 mg IV every 3 weeks (Q3W) for 14 cycles
- Total duration: approximately 42 weeks
| Study group | Role | What they receive |
|---|---|---|
| Neoadjuvant PRTX007 + Pembrolizumab (Response-Adapted Adjuvant Therapy) | Experimental | Participants with resectable Stage III melanoma will receive neoadjuvant treatment with PRTX007 in combination with pembrolizumab prior to definitive surgical resection. Following surgery, participants will receive response-adapted adjuvant therapy based on pathologic response. Participants achieving a major pathologic response (MPR) may receive observation or pembrolizumab alone, while participants without MPR will receive adjuvant PRTX007 in combination with pembrolizumab. Receives: Drug: PRTX007; Drug: Pembrolizumab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Major Pathologic Response (MPR) Rate
Major pathologic response (MPR) is defined as ≤10% residual viable tumor cells in the resected tumor specimen following completion of neoadjuvant therapy, as assessed by central pathology review.
Measured: At time of surgical resection (approximately 9 weeks after initiation of treatment)
Secondary outcomes (9)
Incidence of Adverse Events (AEs), Serious Adverse Events (SAEs), Immune-Related AEs (irAEs), and Dose-Limiting Toxicities (DLTs)
Number and severity of adverse events, serious adverse events, immune-related adverse events, and dose-limiting toxicities, graded according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 6.0.
Measured: From first dose of study treatment through end of study (approximately up to 52 weeks)
Number of participants with abnormal physical examination findings, abnormal vital signs, abnormal Eastern Cooperative Oncology Group (ECOG) performance status, and abnormal clinical laboratory parameters
Measured: Baseline through end of study (approximately up to 52 weeks)
Pathologic Complete Response (pCR) Rate
Pathologic complete response (pCR) is defined as the absence of residual viable tumor cells (0%) in the resected tumor specimen following neoadjuvant therapy, as assessed by central pathology review.
Measured: At time of surgical resection (approximately 9 weeks after initiation of treatment)
Event-Free Survival (EFS)
Event-free survival (EFS) is defined as the time from first dose of study treatment to any of the following events: disease progression or toxicity preventing surgery during neoadjuvant treatment; recurrence of disease after surgery; failure to achieve complete resection (R0 or R1); or death from any cause.
Measured: From first dose up to 1 year
Overall Survival (OS)
Overall survival is defined as the time from first dose of study treatment to death from any cause.
Measured: From first dose through end of study (approximately up to 52 weeks or longer if followed)
Pharmacokinetics of PRTX007
Plasma concentrations of PRTX007 and its active metabolite will be measured to characterize pharmacokinetic parameters using validated analytical methods.
Measured: During treatment period (multiple time points from baseline through approximately 9 weeks and selected later time points)
Changes in cytokine, chemokine and soluble PD-1/PD-L1 biomarkers
Measured: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Changes in mRNA expression
Measured: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Changes in immune cell activation and proliferation markers
Measured: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 May 2026
- Study start1 Jul 2026
- Primary completionDec 2027 (estimated)
- Study completionJun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Melanoma Stage IIIStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Primmune Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07565285
- Sponsor's protocol ID
- PRTX007-003
- Acronym
- INFLECTION-003
- Status last verified
- Oct 2026
- First submitted
- 20 Apr 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the study involves an investigational product and the sponsor has not established a data sharing plan at this time.
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Study to Investigate the Activity of Neoadjuvant PRTX007 Combined With Pembrolizumab in Participants With Stage III Melanoma (INFLECTION-003)
- ClinicalTrials.gov ID
- NCT07565285
- Acronym / sponsor ID
- INFLECTION-003 / PRTX007-003
- Conditions
- Melanoma Stage III
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Primmune Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 1 Jul 2026 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Jun 2029 (estimated)
- First posted
- 4 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This Phase 2, multi-center, single-arm study evaluates the safety, tolerability, and activity of neoadjuvant PRTX007 in combination with pembrolizumab in participants with resectable Stage III melanoma. Neoadjuvant immunotherapy has demonstrated improved clinical outcomes compared with adjuvant-only approaches, but there remains a need to enhance pathologic response rates without significant added toxicity.
Participants will receive oral PRTX007, a Toll-like receptor 7 (TLR7) agonist prodrug, administered in combination with intravenous pembrolizumab prior to surgical resection. The primary objective is to determine the major pathologic response (MPR) rate following neoadjuvant therapy. Secondary objectives include evaluation of safety, pathologic complete response, event-free survival, overall survival, pharmacokinetics, and immune-related biomarkers.
This study aims to determine whether the addition of PRTX007 to pembrolizumab improves antitumor immune responses and clinical outcomes in patients with Stage III melanoma.
Detailed description
This study investigates whether combining the TLR7 agonist PRTX007 with pembrolizumab enhances immune-mediated tumor response in the neoadjuvant setting for Stage III melanoma, with the goal of improving pathologic response rates and clinical outcomes while maintaining an acceptable safety profile.
Design This is a Phase 2, multi-center, open-label, single-arm study conducted in Australia. The study will enroll approximately 48 participants with resectable Stage III melanoma.
The study consists of two parts:
- Part A: 24 participants will be enrolled, including an initial dose-escalation safety run-in using a 3+3 design to evaluate tolerability and dose-limiting toxicities.
- Part B: An additional 24 participants will be enrolled if sufficient activity is observed in Part A.
Treatment Plan
Participants will receive neoadjuvant therapy consisting of:
- PRTX007: Oral administration for 3 days on and 4 days off per week for 9 cycles (7-day cycles)
- Pembrolizumab: 200 mg intravenous infusion every 3 weeks for 3 cycles Following completion of neoadjuvant therapy, participants will undergo definitive surgical resection.
Post-surgical treatment will be response-adapted:
- Participants achieving MPR may receive observation or pembrolizumab alone
- Participants without MPR will receive adjuvant PRTX007 in combination with pembrolizumab
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Neoadjuvant PRTX007 + Pembrolizumab (Response-Adapted Adjuvant Therapy) | Experimental | Drug: PRTX007, Drug: PembrolizumabParticipants with resectable Stage III melanoma will receive neoadjuvant treatment with PRTX007 in combination with pembrolizumab prior to definitive surgical resection. Following surgery, participants will receive response-adapted adjuvant therapy based on pathologic response. Participants achieving a major pathologic response (MPR) may receive observation or pembrolizumab alone, while participants without MPR will receive adjuvant PRTX007 in combination with pembrolizumab. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adults aged 18 years or older
- Histologically confirmed, resectable Stage III cutaneous melanoma.
- Candidate for curative-intent surgical resection
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
- Adequate organ function
Key exclusion criteria (7 listed)
- Prior systemic therapy for melanoma, including immunotherapy
- Uveal melanoma or mucosal melanoma.
- Active autoimmune disease requiring systemic treatment
- Primary immunodeficiency or use of systemic immunosuppressive therapy
- Women who are pregnant or breastfeeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PRTX007PRTX007 is an orally administered prodrug of PRX034, a Toll-like receptor 7 (TLR7) agonist designed to activate innate and adaptive immune responses. NEOADJUVANT REGIMEN * 600 mg orally once daily (safety run-in participants) or * 750 mg orally once daily (subsequent participants) * Administered 3 days on, 4 days off (7-day cycle) * Total of 9 cycles (9 weeks) ADJUVANT REGIMEN (IF NO MPR) * 750 mg orally once daily * Administered 3 days on, 4 days off * Total of 12 cycles (12 weeks) | Drug | Neoadjuvant PRTX007 + Pembrolizumab (Response-Adapted Adjuvant Therapy) |
| PembrolizumabPembrolizumab is a programmed cell death protein-1 (PD-1) blocking antibody administered by intravenous infusion NEOADJUVANT REGIMEN * 200 mg IV every 3 weeks (Q3W) * Total of 3 cycles (9 weeks) ADJUVANT REGIMEN * 400 mg IV every 6 weeks (Q6W) for 7 cycles OR * 200 mg IV every 3 weeks (Q3W) for 14 cycles * Total duration: approximately 42 weeks | Drug | Neoadjuvant PRTX007 + Pembrolizumab (Response-Adapted Adjuvant Therapy) |
Primary outcome
Major Pathologic Response (MPR) Rate
Time frame: At time of surgical resection (approximately 9 weeks after initiation of treatment)
Major pathologic response (MPR) is defined as ≤10% residual viable tumor cells in the resected tumor specimen following completion of neoadjuvant therapy, as assessed by central pathology review.
9 secondary outcomes
Incidence of Adverse Events (AEs), Serious Adverse Events (SAEs), Immune-Related AEs (irAEs), and Dose-Limiting Toxicities (DLTs)
Time frame: From first dose of study treatment through end of study (approximately up to 52 weeks)
Number of participants with abnormal physical examination findings, abnormal vital signs, abnormal Eastern Cooperative Oncology Group (ECOG) performance status, and abnormal clinical laboratory parameters
Time frame: Baseline through end of study (approximately up to 52 weeks)
Pathologic Complete Response (pCR) Rate
Time frame: At time of surgical resection (approximately 9 weeks after initiation of treatment)
Event-Free Survival (EFS)
Time frame: From first dose up to 1 year
Overall Survival (OS)
Time frame: From first dose through end of study (approximately up to 52 weeks or longer if followed)
Pharmacokinetics of PRTX007
Time frame: During treatment period (multiple time points from baseline through approximately 9 weeks and selected later time points)
Changes in cytokine, chemokine and soluble PD-1/PD-L1 biomarkers
Time frame: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Changes in mRNA expression
Time frame: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Changes in immune cell activation and proliferation markers
Time frame: Baseline through treatment period (up to approximately 9 weeks and selected later time points)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared because the study involves an investigational product and the sponsor has not established a data sharing plan at this time.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing PRTX007 and Pembrolizumab in people with Melanoma Stage III, run by Primmune Therapeutics, Inc. at 7 sites in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Gunjan Mody (+61 2 9199 9596, gunjan.mody@novotech-cro.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Major Pathologic Response (MPR) Rate (time frame: At time of surgical resection (approximately 9 weeks after initiation of treatment)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Oct 2026.