Prostate CancerPhase 3PrTK03NCT01436968
Phase 3 Study of ProstAtak® Immunotherapy With Standard Radiation Therapy for Localized Prostate Cancer
A Phase 3 study testing Aglatimagene besadenovec + valacyclovir in people with Prostate Cancer, run by Candel Therapeutics, Inc. at 73 sites in 2 countries.
Trial summary
The purpose of this study is to evaluate the effectiveness of ProstAtak® immunotherapy in combination with radiation therapy for patients with intermediate-high risk localized prostate cancer. ProstAtak kills tumor cells and stimulates a cancer vaccine effect. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer
- What is being tested?
- Aglatimagene besadenovec + valacyclovir
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 711 participants
- Where
- 73 sitesin 2 countries
- Study dates
- Sep 2011to Dec 2030
- Phase
- Phase 3
- 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
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Localized prostate cancer meeting the NCCN criteria of Intermediate Risk or patients having only one NCCN high-risk feature
- NCCN Intermediate Risk is defined as having at least one of the following: PSA 10-20 ng/ml, Gleason score =7, T2b-T2c
- High Risk with a single high risk feature is defined as having only one of the following: PSA>20 ng/ml, Gleason score 8-10, or T3a
- Excluded are those in the following risk groups: Low risk; High risk with more than 1 high risk factor; Locally advanced/very high risk=T3b-T4; Metastatic: N1 or M1
- Planning to undergo standard prostate-only external beam radiation therapy
- ECOG Performance Status 0-2
Who cannot join
- Liver disease, including known cirrhosis or active hepatitis
- Patients on systemic corticosteroids (>10mg prednisone per day) or other immunosuppressive drugs
- Known HIV+ patients
- Regional lymph node involvement or distant metastases
- Patients planning to receive whole pelvic irradiation
- Prior treatment for prostate cancer, except TURP or ADT. For ADT, it may only be given for a maximum of 6 months
- Patients who had or plan to have orchiectomy as the form of hormonal ablation
- Known sensitivity or allergic reactions to acyclovir or valacyclovir
Trial locations and contacts
73 sites in 2 countries.
73 sites in 2 countries
United States72 sites
New Mexico Oncology Hematology Consultants (NMOHC)
Albuquerque, New Mexico, 87109
University of New Mexico Cancer Center
Albuquerque, New Mexico, 87131
Potomac Urology Center
Alexandria, Virginia, 22311
Urology Austin
Austin, Texas, 78705
Austin Urology Institute
Austin, Texas, 78758
Austin Urology Institute - Northwest Austin Cancer Center
Austin, Texas, 78759
MidLantic Urology
Bala-Cynwyd, Pennsylvania, 19004
VA Maryland Health Care System
Baltimore, Maryland, 21201
Chesapeake Urology Research Associates
Baltimore, Maryland, 21204
The Johns Hopkins University School of Medicine, The Sidney Kimmel Comprehensive Cancer Center
Baltimore, Maryland, 21231
Walter Reed National Military Medical Center
Bethesda, Maryland, 20889
Ralph H. Johnson Veterans Affairs Medical Center
Charleston, South Carolina, 29401
New Jersey Urology - Cherry Hill
Cherry Hill, New Jersey, 08003
Jesse Brown VA Medical Center
Chicago, Illinois, 60612
The University of Chicago
Chicago, Illinois, 60637
Cincinnati VA Medical Center
Cincinnati, Ohio, 45220
VA North Texas Health Care System
Dallas, Texas, 75216
Urology Clinics of North Texas
Dallas, Texas, 75231
Durham VA Health Care System
Durham, North Carolina, 27705
New Jersey Urology - Englewood
Englewood, New Jersey, 07631
21st Century Oncology
Fort Lauderdale, Florida, 33324
MultiCare Regional Cancer Center - Gig Harbor
Gig Harbor, Washington, 98335
Arizona Center for Cancer Care - Gilbert
Gilbert, Arizona, 85297
Arizona Urology Specialists
Glendale, Arizona, 85308
Valley View Hospital
Glenwood Springs, Colorado, 81601
Dr. Irving Fishman's Office
Houston, Texas, 77030
Houston Willowbrook Radiation Oncology
Houston, Texas, 77070
Dr. Ned Stein's Office
Houston, Texas, 77074
Kansas City VA Medical Center
Kansas City, Missouri, 64128
Colorado Clinical Research
Lakewood, Colorado, 80228
21st Century Oncology
Lakewood Rch, Florida, 34202
Sheldon Freedman MD, Ltd.
Las Vegas, Nevada, 89144
VA Northern California Health Care System
Mather, California, 95655
New Jersey Urology - Milburn
Millburn, New Jersey, 07041
Carolina Urologic Research Center, LLC
Myrtle Beach, South Carolina, 29572
21st Century Oncology
Naples, Florida, 34102
Silver Cross Hospital
New Lenox, Illinois, 60451
Southeast Louisiana Veterans Health Care System
New Orleans, Louisiana, 70119
Advanced Radiation Centers of New York (Integrated Medical Professionals)
North Hills, New York, 11042
Adult & Pediatric Urology, P.C.
Omaha, Nebraska, 68114
Advanced Urology
Parker, Colorado, 80134
Arizona Center for Cancer Care - Peoria
Peoria, Arizona, 85381
Fox Chase Cancer Center
Philadelphia, Pennsylvania, 19111-2497
Arizona Center for Cancer Care - Deer Valley
Phoenix, Arizona, 85027
Arizona Oncology Services Foundation
Phoenix, Mesa, Scottsdale, Sedona, Arizona, 85260
21st Century Oncology
Plantation, Florida, 33324
Clinical Research Center of Florida
Pompano Beach, Florida, 33060
VA Portland Health Care System
Portland, Oregon, 97239
VA Sierra Nevada Health Care System
Reno, Nevada, 89502
Hunter Holmes McGuire VA Medical Center
Richmond, Virginia, 23249
New Jersey Urology - Saddle Brook
Saddle Brook, New Jersey, 07663
Salem VA Medical Center
Salem, Virginia, 24153
South Texas San Antonio VA Healthcare System
San Antonio, Texas, 78229-4404
The University of Texas Health Science Center at San Antonio
San Antonio, Texas, 78229
Arizona Center for Cancer Care - Osborne
Scottsdale, Arizona, 85251
Arizona Center for Cancer Care - Shea
Scottsdale, Arizona, 85258
Oregon Urology Institute
Springfield, Oregon, 97477
Arizona Center for Cancer Care - Surprise
Surprise, Arizona, 85374
Associated Medical Professionals of NY, PLLC
Syracuse, New York, 13210
MultiCare Regional Cancer Center - Tacoma
Tacoma, Washington, 98405
James A. Haley Veteran's Hospital
Tampa, Florida, 33612
Florida Urology Partners
Tampa, Florida, 33615
James J. Peters VA Medical Center
The Bronx, New York, 10468
Texas Urology Specialists-The Woodlands
The Woodlands, Texas, 77385
The Methodist Hospital - The Woodlands
The Woodlands, Texas, 77385
Texas Urology Specialists
Tomball, Texas, 77375
Southern Arizona VA Health Care System
Tucson, Arizona, 85723
Precision Radiation Oncology
Tustin, California, 92780
Urology of Virginia, PLLC
Virginia Beach, Virginia, 23462
Sibley Memorial Hospital
Washington D.C., District of Columbia, 20016
New Jersey Urology - West Orange
West Orange, New Jersey, 07052
University of Massachusetts Medical School
Worcester, Massachusetts, 01605
Puerto Rico1 site
VA Caribbean Healthcare System
San Juan, Puerto Rico, 00921
About this study
Official title: A Randomized Controlled Trial of ProstAtak® as Adjuvant to Up-front Radiation Therapy For Localized Prostate Cancer
The purpose of this study is to evaluate the effectiveness of ProstAtak® immunotherapy in combination with radiation therapy for patients with intermediate-high risk localized prostate cancer. ProstAtak kills tumor cells and stimulates a cancer vaccine effect. Killing tumor cells in an immune stimulatory environment induces the body's immune system to detect and destroy cancer cells. ProstAtak has shown synergy with radiation without added toxicity and lower than expected recurrence rates in previous clinical trials. The hypothesis is that ProstAtak can lead to improvement in the clinical outcome for patients with prostate cancer. Participants will be randomized to the ProstAtak or control arm at a 2:1 ratio. Both arms receive standard external beam radiation therapy. Short-term androgen deprivation therapy may be given but is not required.
- Conditions
- Prostate Cancer
- Being tested
- Aglatimagene besadenovec + valacyclovir, Placebo + valacyclovir
- Keywords
- immunotherapy, cytotoxicity, tumor vaccine, prostate cancer, radiotherapy
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Aglatimagene besadenovec + valacyclovirBiological
Also called AdV-tk, CAN-2409
Patients will receive three courses of ProstAtak® each consisting of aglatimagene besadenovec injection + oral valacyclovir. AdV-tk injection will be delivered to the prostate via trans-rectal ultrasound guided injection as follows:
- The first injection will be given at least 15 days and not more than 8 weeks before starting radiation.
- The second injection will be 0-3 days before initiation of radiation therapy.
- The third injection will be 15-22 days after the 2nd injection.
The prodrug, valacyclovir, will be administered at a fixed dose for 14 days after each AdV-tk injection.
Standard external beam radiation therapy will be delivered to the prostate. Short-term androgen deprivation therapy (maximum of 6 months) is optional but must be decided before enrollment to allow for stratification.
Placebo + valacyclovirBiological
Patients will receive three courses each consisting of placebo injection + oral valacyclovir. Placebo injection will be delivered to the prostate via trans-rectal ultrasound guided injection as follows:
- The first injection will be given at least 15 days and not more than 8 weeks before starting radiation.
- The second injection will be 0-3 days before initiation of radiation therapy.
- The third injection will be 15-22 days after the 2nd injection.
The prodrug, valacyclovir, will be administered at a fixed dose for 14 days after each placebo injection.
Standard external beam radiation therapy will be delivered to the prostate. Short-term androgen deprivation therapy (maximum of 6 months) is optional but must be decided before enrollment to allow for stratification.
| Study group | Role | What they receive |
|---|---|---|
| ProstAtak® | Experimental | Aglatimagene besadenovec (CAN-2409) + valacyclovir + radiation therapy +/- ADT Receives: Biological: Aglatimagene besadenovec + valacyclovir |
| Control | Placebo comparator | Placebo + valacyclovir + radiation therapy +/- ADT Receives: Biological: Placebo + valacyclovir |
What is being measured
The primary outcome is the main question the study is designed to answer.
Disease free survival defined as the time from randomization until the date of the first failure event will be compared for the ProstAtak® arm versus the placebo control arm. The analyses will be based on the intent to treat population.
Measured: Assessed at each visit every 6 months through year 5 until event occurs.
Secondary outcomes (4)
Prostate cancer specific survival and overall survival will be compared for the ProstAtak® arm versus the placebo control arm.
Measured: Assessed at each visit every 6 months through year 5 after which long-term follow up of general health status will continue yearly.
PSA nadir will be compared for the ProstAtak® arm versus the placebo control arm.
Measured: Assessed at each visit every 6 months through year 5.
Patient reported Health Related Quality of Life outcomes will be collected using the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. The change in QOL over time will be compared for the ProstAtak® arm versus the placebo control arm.
Measured: Assessed at baseline and at 3, 6, 12, 18 and 24 months after completion of radiation.
The safety profile will be characterized by collection of adverse event information and laboratory values during the treatment phase (until the completion of radiation). Data on late effects will be collected after radiation completion.
Measured: Assessed at each visit and continuously throughout the study.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Sep 2011 (estimated)
- Study startSep 2011
- Primary completionAug 2024
- Study completionDec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Prostate CancerStudies 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 711 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Candel Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01436968
- Sponsor's protocol ID
- PrTK03
- Acronym
- PrTK03
- Status last verified
- Sep 2026
- First submitted
- 19 Sep 2011
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
Publications
DeWeese TL, Manzanera A, Sylvester J, Wheeler T, Schroeder T, Gejerman G, Chesnut G, Facelle TM, Garzotto MG, Pieczonka C, Gandhi NM, Sukin S, Liss MA, Tutrone R, Mehlhaff B, Savage SJ, Goody M, Vogt J, Rao S, Polanco MLS, Barone F, Nichols WG, Tak PP; PrTK03 study team. Aglatimagene besadenovec (CAN-2409) with radiotherapy for patients with localised prostate cancer: a phase 3, multicentre, randomised, double-blind, placebo-controlled trial. Lancet Oncol. 2026 Jun;27(6):673-685. doi: 10.1016/S1470-2045(26)00071-9.
PubMed 42225101
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial of ProstAtak® as Adjuvant to Up-front Radiation Therapy For Localized Prostate Cancer
- ClinicalTrials.gov ID
- NCT01436968
- Acronym / sponsor ID
- PrTK03 / PrTK03
- Conditions
- Prostate Cancer
- Keywords
- immunotherapy, cytotoxicity, tumor vaccine, prostate cancer, radiotherapy
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 711 participants (estimated)
- Lead sponsor
- Candel Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- Sep 2011
- Primary completion
- Aug 2024 (actual)
- Study completion
- Dec 2030 (estimated)
- First posted
- 20 Sep 2011 (estimated)
- 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.
The purpose of this study is to evaluate the effectiveness of ProstAtak® immunotherapy in combination with radiation therapy for patients with intermediate-high risk localized prostate cancer. ProstAtak kills tumor cells and stimulates a cancer vaccine effect. Killing tumor cells in an immune stimulatory environment induces the body's immune system to detect and destroy cancer cells. ProstAtak has shown synergy with radiation without added toxicity and lower than expected recurrence rates in previous clinical trials. The hypothesis is that ProstAtak can lead to improvement in the clinical outcome for patients with prostate cancer. Participants will be randomized to the ProstAtak or control arm at a 2:1 ratio. Both arms receive standard external beam radiation therapy. Short-term androgen deprivation therapy may be given but is not required.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ProstAtak® | Experimental | Biological: Aglatimagene besadenovec + valacyclovirAglatimagene besadenovec (CAN-2409) + valacyclovir + radiation therapy +/- ADT |
| Control | Placebo comparator | Biological: Placebo + valacyclovirPlacebo + valacyclovir + radiation therapy +/- ADT |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Localized prostate cancer meeting the NCCN criteria of Intermediate Risk or patients having only one NCCN high-risk feature
- Planning to undergo standard prostate-only external beam radiation therapy
- ECOG Performance Status 0-2
Key exclusion criteria (8 listed)
- Liver disease, including known cirrhosis or active hepatitis
- Patients on systemic corticosteroids (>10mg prednisone per day) or other immunosuppressive drugs
- Known HIV+ patients
- Regional lymph node involvement or distant metastases
- Patients planning to receive whole pelvic irradiation
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 |
|---|---|---|
| Aglatimagene besadenovec + valacyclovirAlso: AdV-tk, CAN-2409Patients will receive three courses of ProstAtak® each consisting of aglatimagene besadenovec injection + oral valacyclovir. AdV-tk injection will be delivered to the prostate via trans-rectal ultrasound guided injection as follows: 1. The first injection will be given at least 15 days and not more than 8 weeks before starting radiation. 2. The second injection will be 0-3 days before initiation of radiation therapy. 3. The third injection will be 15-22 days after the 2nd injection. The prodrug, valacyclovir, will be administered at a fixed dose for 14 days after each AdV-tk injection. Standard external beam radiation therapy will be delivered to the prostate. Short-term androgen deprivation therapy (maximum of 6 months) is optional but must be decided before enrollment to allow for stratification. | Biological | ProstAtak® |
| Placebo + valacyclovirPatients will receive three courses each consisting of placebo injection + oral valacyclovir. Placebo injection will be delivered to the prostate via trans-rectal ultrasound guided injection as follows: 1. The first injection will be given at least 15 days and not more than 8 weeks before starting radiation. 2. The second injection will be 0-3 days before initiation of radiation therapy. 3. The third injection will be 15-22 days after the 2nd injection. The prodrug, valacyclovir, will be administered at a fixed dose for 14 days after each placebo injection. Standard external beam radiation therapy will be delivered to the prostate. Short-term androgen deprivation therapy (maximum of 6 months) is optional but must be decided before enrollment to allow for stratification. | Biological | Control |
Primary outcome
Disease free survival defined as the time from randomization until the date of the first failure event will be compared for the ProstAtak® arm versus the placebo control arm. The analyses will be based on the intent to treat population.
Time frame: Assessed at each visit every 6 months through year 5 until event occurs.
4 secondary outcomes
Prostate cancer specific survival and overall survival will be compared for the ProstAtak® arm versus the placebo control arm.
Time frame: Assessed at each visit every 6 months through year 5 after which long-term follow up of general health status will continue yearly.
PSA nadir will be compared for the ProstAtak® arm versus the placebo control arm.
Time frame: Assessed at each visit every 6 months through year 5.
Patient reported Health Related Quality of Life outcomes will be collected using the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. The change in QOL over time will be compared for the ProstAtak® arm versus the placebo control arm.
Time frame: Assessed at baseline and at 3, 6, 12, 18 and 24 months after completion of radiation.
The safety profile will be characterized by collection of adverse event information and laboratory values during the treatment phase (until the completion of radiation). Data on late effects will be collected after radiation completion.
Time frame: Assessed at each visit and continuously throughout the study.
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 2 Oct 2026.
- Derived from this study: PubMed 42225101DeWeese TL, Manzanera A, Sylvester J, Wheeler T, Schroeder T, Gejerman G, Chesnut G, Facelle TM, Garzotto MG, Pieczonka C, Gandhi NM, Sukin S, Liss MA, Tutrone R, Mehlhaff B, Savage SJ, Goody M, Vogt J, Rao S, Polanco MLS, Barone F, Nichols WG, Tak PP; PrTK03 study team. Aglatimagene besadenovec (CAN-2409) with radiotherapy for patients with localised prostate cancer: a phase 3, multicentre, randomised, double-blind, placebo-controlled trial. Lancet Oncol. 2026 Jun;27(6):673-685. doi: 10.1016/S1470-2045(26)00071-9.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
73 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Aglatimagene besadenovec + valacyclovir in people with Prostate Cancer, run by Candel Therapeutics, Inc. at 73 sites in 2 countries.
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 8 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: under way, not looking for participants, as of the sponsor's last update on 2 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 73 sites in United States, Puerto Rico. 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. Some participants in this study may receive a placebo. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Disease free survival defined as the time from randomization until the date of the first failure event will be compared for the ProstAtak® arm versus the placebo control arm. The analyses will be based on the intent to treat population. (time frame: Assessed at each visit every 6 months through year 5 until event occurs.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01436968, which also lists 1 linked publication.
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 2 Oct 2026; AzTrials last refreshed its copy on 6 Nov 2026.