DNAJB1-PRKACA Fusion Kinase Peptide Vaccine Combined With Nivolumab and Ipilimumab for Patients With Fibrolamellar Hepatocellular Carcinoma

DNAJB1-PRKACA Fusion Kinase Peptide Vaccine Combined With Nivolumab and Ipilimumab for Patients With Fibrolamellar Hepatocellular Carcinoma

A Pilot Study of a DNAJB1-PRKACA Fusion Kinase Peptide Vaccine Combined With Nivolumab and Ipilimumab for Patients With Fibrolamellar Hepatocellular Carcinoma

The primary objective of the trial is the safety and tolerability of administering a vaccine targeting the DNAJB1-PRKACA fusion kinase, in combination with nivolumab and ipilimumab in patients with unresectable or metastatic FLC and to assess the T-cell response.

DNAJB1-PRKACA Peptide Vaccine, Nivolumab, Ipilimumab, Anti-PD-1 (receptor blocking antibody), Anti-CTLA-4 (receptor blocking antibody), Neoantigen Vaccines, Cancer Vaccines, Immunotherapy, Fibrolamellar Hepatocellular Cancer (FLC)

DNAJB1-PRKACA peptide vaccine: Day 1, 8, 15 of cycle 1 and Day 1 of cycle 2, 3, 4 and 5 (priming phase). Boost vaccinations: every 3 cycles beginning C6D1. For Cohort A-(Initial) only: Patients with FLC cancer with no prior checkpoint inhibitor therapy treatment. DNAJB1-PRKACA peptide vaccine: Day 1, 8, 15 of cycle 1 and on Day 1 of cycle 2, 3 and 4 (priming phase). Boost vaccinations: every 3 cycles beginning C5D1. Cohort A-(Expansion): Patients with FLC cancer with no prior checkpoint inhibitor treatment. Cohort B: Patients with FLC cancer with prior checkpoint inhibitor treatment. Cohort C: Patients with non-FLC cancer (solid tumors) with prior checkpoint inhibitor treatment eligible. Drug: 0.3 mg DNAJB1-PRKACA peptide vaccine + 0.5mg Poly-ICLC

Cohort A (Initial): Nivolumab 3mg/kg will be administered as a 30 minute IV infusion (-10/+15min) on Day 1 of Cycle 2-5 during the priming phase. Boost/maintenance vaccinations will be administered as a flat dose of 480mg every 4 weeks starting on Day 1 of Cycle 6. Cohort A (Expansion), B and C: Nivolumab 3mg/kg will be administered as a 30 minute IV infusion (-10/+15min) on Day 1 of Cycle 1-4 during the priming phase. Boost/maintenance vaccinations will be administered as a flat dose of 480mg every 4 weeks starting on Day 1 of Cycle 5. Drug: 3mg/kg and 480mg IV

Cohort A (Initial): Ipilimumab (1 mg/kg) will be administered as a 30 minute IV infusion (-10/+15min) on Day 1 of Cycles 2, 3, 4 and 5 of the study, every 3 weeks of the priming phase. Cohort A (Expansion), B and C: Ipilimumab (1 mg/kg) will be administered as a 30 minute IV infusion (-10/+15min) on Day 1 of Cycles 1, 2, 3 and 4 of the study, every 3 weeks of the priming phase. Drug: 1mg/kg IV

Number of participants experiencing study drug-related adverse events Grade 3 or higher as defined by CTCAE v5.0

Fold change in interferon-producing DNAJB1-PRKACA-specific cluster of differentiation 8 (CD8) T cells at 10 weeks

Evaluated by the fold change in interferon-producing DNAJB1-PRKACA-specific CD8 cells after vaccination at 10 weeks compare to pre-vaccination baseline.

Fold change in interferon-producing DNAJB1-PRKACA-specific cluster of differentiation 4 (CD4) T cells at 10 weeks

Evaluated by the fold change in interferon-producing DNAJB1-PRKACA-specific CD4 T cells after vaccination at 10 weeks compare to pre-vaccination baseline.

ORR is defined as the number of patients achieving a complete response (CR) or partial response (PR) based on the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) at any time during the study. CR = disappearance of all target lesions, PR is =>30% decrease in sum of diameters of target lesions, progressive disease (PD) is >20% increase in sum of diameters of target lesions, stable disease (SD) is <30% decrease or <20% increase in sum of diameters of target lesions.

Number of weeks from the start date of PR or CR (whichever response is recorded first) and subsequently confirmed to the first date of disease progression or death is documented per RECIST 1.1. CR = disappearance of all target lesions, PR is =>30% decrease in sum of diameters of target lesions.

DCR is defined as the number of patients achieving a complete response (CR) or partial response (PR) and stable disease (SD) based on the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) at any time during the study. CR = disappearance of all target lesions, PR is =>30% decrease in sum of diameters of target lesions, progressive disease (PD) is >20% increase in sum of diameters of target lesions, stable disease (SD) is <30% decrease or <20% increase in sum of diameters of target lesions.

PFS is defined as number of months from the date of first treatment until first documented local progression or death due to any cause. Per RECIST 1.1 criteria, CR = disappearance of all target lesions, Partial Response (PR) is =>30% decrease in sum of diameters of target lesions, Progressive Disease (PD) is >20% increase in sum of diameters of target lesions, Stable Disease (SD) is <30% decrease or <20% increase in sum of diameters of target lesions. Estimation based on the Kaplan-Meier curve.

OS will be measured from date of first dose until death or end of follow-up (OS will be censored on the date the subject was last known to be alive for subjects without documentation of death at the time of analysis). Estimation based on the Kaplan-Meier curve.

Inclusion Criteria: Cohort A and B: Must have histologically confirmed FLC (fibrolamellar hepatocellular cancer) that is metastatic or unresectable. Cohort C: Patients with histologically proven metastatic or unresectable DNAJB1-PRKACA fusion transcript positive solid tumor malignancies, non-FLC solid tumors. Cohort A and B: Age > 12 years. Note: Subjects age > 12 years but <18 are eligible to enroll only after 6 adult patients have enrolled on the study. Cohort A and B: Patients < 18 years old must have a body weight ≥40 kg. Cohort C: Patients must be Age ≥ 18 years. All Cohorts: • Presence of DNAJB1-PRKACA fusion transcript, assessed by RNA-sequencing, DNA-sequencing, or in situ hybridization in the archival tissue. ECOG performance status of ≤2 (Karnofsky ≥60%) Patients must have adequate liver, kidney and marrow function defined by study-specified laboratory tests prior to initial study drug. Patients must have measurable disease per RECIST 1.1. Patients > 18 years old must have an accessible non-bone tumor lesion from which serial core biopsy specimens can be obtained. Must be willing to provide tissue and blood samples for mandatory translational research. Woman of childbearing potential must have a negative pregnancy test and follow contraceptive guidelines as defined per protocol. Men must use acceptable form of birth control while on study. Ability to understand and willingness to sign a written informed consent document. Exclusion Criteria: Cohort A and C: Patients with a history of prior treatment with checkpoint inhibitors, such as anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, anti-OX-40, anti-CD40, anti-CTLA-4, or anti-LAG-3 antibodies. NOTE: Prior therapy with interferon-alpha is allowed. Cohort B: Participants a with history of unacceptable, life-threatening toxicity related to prior immune therapy (eg, anti-CTLA-4 or anti-PD-1/PD-L1 treatment, any other antibody or drug specifically targeting T-cell co-stimulation or immune checkpoint pathways) except those that are unlikely to re-occur with standard countermeasures (eg, hormone replacement after endocrinopathy). All Cohorts: Have had chemotherapy or other systemic therapy or radiotherapy, as follows: Have had chemotherapy, biological cancer therapy, or radiation 14 days prior to the first dose of study drug. Have had surgery within 28 days of dosing of investigational agent, excluding minor procedures (dental work, skin biopsy, etc.), celiac plexus block, and biliary stent placement. Have received other approved or investigational agents or device within 28 days of the first dose of study drug. Have not recovered from acute adverse events to grade ≤1 or baseline due to agents administered. Have received any non-oncology live vaccine therapy used for prevention of infectious diseases within 28 days of study treatment Known sensitivity to or history of allergic reactions to investigational drug (s). Hypersensitivity reaction to any monoclonal antibody. Has active autoimmune disease that has required systemic treatment in the past 2 years, or a documented history of clinically severe autoimmune disease, or a syndrome that requires systemic steroids or immunosuppressive agents. Presence of any tissue or organ allograft, regardless of need for immunosuppression, including corneal allograft. Patients with a history of allogeneic hematopoeitic stem cell transplant will be excluded. Has a diagnosis of immunodeficiency. Systemic treatment with either corticosteroids (>10 mg daily prednisone equivalents) or other immunosuppressive medications within 7 days of study drug administration. Symptomatic interstitial lung disease. Has a pulse oximetry of <92% on room air or is on supplemental home oxygen. Active or untreated brain metastases or leptomeningeal metastases. Uncontrolled intercurrent illness including, but not limited to, uncontrolled infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia, metastatic cancer, or psychiatric illness/social situations that would limit compliance with study requirements. Are pregnant or breastfeeding. Infection with HIV or hepatitis B or C. Have had evidence of active or acute diverticulitis, intra-abdominal abscess, or GI obstruction. Unwilling or unable to follow the study schedule for any reason. Any other sound medical, psychiatric, and/or social reason as determined by the Investigator. Any illicit drugs or other substance abuse. Clinically meaningful ascites.

Short SS, Kastenberg ZJ, Wei G, Bondoc A, Dasgupta R, Tiao GM, Watters E, Heaton TE, Lotakis D, La Quaglia MP, Murphy AJ, Davidoff AM, Mansfield SA, Langham MR, Lautz TB, Superina RA, Ott KC, Malek MM, Morgan KM, Kim ES, Zamora A, Lascano D, Roach J, Murphy JT, Rothstein DH, Vasudevan SA, Whitlock R, Lal DR, Hallis B, Butter A, Baertschiger RM, Lapidus-Krol E, Putra J, Tracy ER, Aldrink JH, Apfeld J, Le HD, Park KY, Rich BS, Glick RD, Fialkowski EA, Utria AF, Meyers RL, Riehle KJ. Histologic type predicts disparate outcomes in pediatric hepatocellular neoplasms: A Pediatric Surgical Oncology Research Collaborative study. Cancer. 2022 Jul 15;128(14):2786-2795. doi: 10.1002/cncr.34256. Epub 2022 May 13.

O'Neill AF, Church AJ, Perez-Atayde AR, Shaikh R, Marcus KJ, Vakili K. Fibrolamellar carcinoma: An entity all its own. Curr Probl Cancer. 2021 Aug;45(4):100770. doi: 10.1016/j.currproblcancer.2021.100770. Epub 2021 Jul 1.