In Situ Vaccine for Low-Grade Lymphoma: Combination of Intratumoral Flt3L and Poly-ICLC With Low-Dose Radiotherapy

  • End date
    Nov 25, 2022
  • participants needed
  • sponsor
    Joshua Brody
Updated on 26 January 2021


Our recent trials combining local radiotherapy with intratumoral administration of TLR agonists - referred to as 'in situ vaccination' - for patients with low-grade lymphoma demonstrated safety, induction of anti-tumor CD8 T cell responses and partial and complete remissions of patients' non-irradiated sites of disease with complete remissions lasting from months to more than three years.

This iteration of the in situ vaccine approach builds on our prior work in ways that should improve its efficacy, by adding Flt3L and changing the toll-like receptors (TLR) agonist to poly-ICLC -an optimal TLR agonist for the type of dendritic cells (DC) recruited by Flt3L. The vaccine is thus in 3 phases:

  1. intratumoral Flt3L administration recruits DC to the tumor
  2. low-dose radiotherapy to release tumor antigens
  3. intratumoral poly-ICLC administration activates tumor-antigen loaded DC


Lymphomas comprise the 5th most common cancer in the U.S. with approximately 80,000 new cases diagnosed in the U.S. each year. Low-grade B-cell lymphomas are the most prevalent subtype amongst these and are considered incurable with standard therapies. Chemotherapy and monoclonal antibody therapy induce temporary remissions, though disease generally recurs, becomes progressively more resistant to therapy and ultimately therapy-resistant. Standard therapies prolong survival, though there is no standard of care regarding when to initiate therapy (versus observation) or the optimal sequence of different therapies. Novel therapies are needed with distinct mechanisms and with greater tolerability profiles. Immunotherapy has a long precedent of being able to cure low-grade lymphomas with allogeneic transplant being curative in a proportion of chemo-refractory patients, though the morbidity of this procedure reduces its broader utilization.

Previously, we completed four trials combining local radiotherapy (a standard of care for these diseases) with intratumoral administration of TLR agonists - an approach we refer to as 'in situ vaccination' for patients with previously untreated or relapsed/refractory low-grade lymphoma. We demonstrated safety, induction of anti-tumor CD8 T cell responses and partial and complete remissions of patients' non-irradiated sites of disease.1, 2 The most recent trials compared previously untreated versus relapsed/refractory patients receiving the same therapy and observed superior responses in the former group, presumably due to immunosuppressive effects of prior treatments in the latter group. The in situ vaccine is premised on pre-clinical data showing this approach to be superior to systemic TLR agonist delivery3 and our clinical results reproduce this finding; in situ vaccination yields superior response rates as compared to trials of systemic TLR agonist therapy for lymphoma.4

This iteration of the in situ vaccine approach builds on our prior work in ways that should improve its efficacy, by making two changes to the prior approach:

  1. intratumoral administration of rhuFlt3L/CDX-301 to recruit dendritic cells to the tumor site
  2. intratumoral administration of poly-ICLC. Flt3L has been safely administered to patients with lymphoma5 and -pre-clinically- has been shown to induce tumor leukocyte infiltration and regression of lymphoma tumors.6, 7 A total of 36 healthy volunteers and 294 cancer patients were treated including only industry-sponsored studies with the prior formulation of this agent (AMG 949) with excellent tolerability and 30 healthy volunteers were recently treated with the current formulation (CDX-301), again with excellent tolerability.

Poly-ICLC has been safely administered to patients with lymphoma8 and -pre-clinically- has been shown to induce natural killer (NK) cell cytolytic activity and regression of lymphoma tumors.9-11 Over 600 healthy volunteers and cancer patients in 17 trials have been treated with comparable doses of poly-ICLC as that used here with excellent tolerability.

Condition Low-Grade B-cell Lymphoma, Low-Grade B-cell Lymphoma, Low-Grade B-cell Lymphoma, Low-Grade B-cell Lymphoma, Low-Grade B-cell Lymphoma, Low-Grade B-cell Lymphoma
Treatment Poly-ICLC, rhuFlt3L/CDX-301
Clinical Study IdentifierNCT01976585
SponsorJoshua Brody
Last Modified on26 January 2021


Yes No Not Sure

Inclusion Criteria

Biopsy-confirmed low-grade B-cell lymphoma or cutaneous T cell lymphoma; specifically, follicular grade 1, 2, or 3A, marginal zone or small lymphocytic lymphoma, or mycosis fungoides of any initial stage. Patients in cohort A must be relapsed/refractory after at least one prior systemic therapy and patients in cohort B must have had no prior systemic therapy
Patients must have at least one site of disease that is accessible for intratumoral injection percutaneously (e.g. inguinal, axillary, cervical, or subcutaneous)
Tumor specimens must be available for immunological studies, either from a previous biopsy or a new biopsy obtained before the initiation Day 1 of the study
Patients must have measurable disease other than the injection site or biopsy site, i.e. greater than 1.5 cm bi-dimensionally on standard computed tomography imaging
ECOG Performance Status of 1 or better (corresponds to Karnofsky Performance Status (KPS) of 70)
Patients must be 18 years of age or older
Adequate bone marrow function: WBC 2,000/L; platelet count 75,000/mm3; ANC 1000/L
Adequate renal function: serum creatinine 2.0mg/dL
Adequate hepatic function: bilirubin 1.5 mg/dL; SGOT/SGPT < 3 x upper limit of normal
Required wash out periods for prior therapy (for cohort B)
Topical therapy: 2 weeks
Chemotherapy: 4 weeks
Radiotherapy: 4 weeks
Other investigational therapy: 4 weeks
Rituximab: 12 weeks
Patients of reproductive potential and their partners must agree to use an effective (> 90% reliability) form of contraception during the study and for 4 weeks following the last study drug administration
Women of reproductive potential must have negative urine pregnancy test
Life expectancy greater than 4 months
Able to comply with the treatment schedule
Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria

Pre-existing autoimmune or antibody -mediated disease including: systemic lupus, erythematosus, rheumatoid arthritis, multiple sclerosis, Sjogren's syndrome, autoimmune thrombocytopenia, history of uveitis. Patients with controlled thyroid disease, or the presence of auto-antibodies without clinical autoimmune disease, are permitted on study
Known history of human immunodeficiency virus (HIV)
Patients with active infection
Known CNS metastases
Prior malignancy (active within 5 years of screening) except basal cell or completely excised non-invasive squamous cell carcinoma of the skin, or in situ squamous cell carcinoma of the cervix
History of allergic reactions to compounds of similar composition to either CDX-301 or poly-ICLC
Current anticoagulant therapy. (ASA 325 mg per day is allowed.)
Significant cardiovascular disease (i.e. NYHA class 3 congestive heart failure; myocardial infarction with the past 6 months; unstable angina; coronary angioplasty with the past 6 months; uncontrolled atrial or ventricular cardiac arrhythmias)
Pregnant or lactating
Any other medical history, including laboratory abnormalities, deemed by the investigator to be likely to interfere with their participation in the study, or to interfere with the interpretation of the results
Clear my responses

How to participate?

Step 1 Connect with a site
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Preferred Language
Other Language
Please verify that you are not a bot.

Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note