Trial Outcomes & Findings for A Study of IMU-131 (HER-Vaxx) in Combination With Chemotherapy or Pembrolizumab in Patients With Metastatic HER2/Neu Over-Expressing Gastric Cancer (nextHERIZON) (NCT NCT05311176)

Last Updated: 2025-05-11

Results Overview

An AE was defined as any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. A summary of other non-serious AEs and all serious AEs, regardless of causality is located in the Reported AE section.

Recruitment status

TERMINATED

Study phase

PHASE2

Target enrollment

7 participants

Primary outcome timeframe

First dose of study drug up to approximately 1.5 years

Results posted on

2025-05-11

Participant Flow

A total of 7 participants were enrolled in the trial. A second arm was planned with IMU 131 + chemotherapy (ramucirumab and paclitaxel) but did not enroll any participants.

Participant milestones

Participant milestones
Measure	IMU-131 + Pembrolizumab Participants received IMU-131 intramuscularly (IM) on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered every 3 weeks (Q3W) starting on Day 1 until disease progression or treatment discontinuation.
Overall Study STARTED	7
Overall Study Received at Least 1 Dose of Study Drug	7
Overall Study COMPLETED	0
Overall Study NOT COMPLETED	7

Reasons for withdrawal

Reasons for withdrawal
Measure	IMU-131 + Pembrolizumab Participants received IMU-131 intramuscularly (IM) on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered every 3 weeks (Q3W) starting on Day 1 until disease progression or treatment discontinuation.
Overall Study Death	6
Overall Study Sponsor discontinued the study	1

Baseline Characteristics

A Study of IMU-131 (HER-Vaxx) in Combination With Chemotherapy or Pembrolizumab in Patients With Metastatic HER2/Neu Over-Expressing Gastric Cancer (nextHERIZON)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	IMU-131 + Pembrolizumab n=7 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Age, Continuous	60.1 years STANDARD_DEVIATION 6.64 • n=5 Participants
Sex: Female, Male Female	0 Participants n=5 Participants
Sex: Female, Male Male	7 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	7 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants
Race (NIH/OMB) White	6 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants

PRIMARY outcome

Timeframe: First dose of study drug up to approximately 1.5 years

Population: The Safety Analysis Set included all participants who received at least 1 dose of study treatment.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=7 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Number of Participants With Treatment-emergent Adverse Events (TEAEs)	6 Participants

PRIMARY outcome

Timeframe: First dose of study drug up to approximately 1.5 years

Population: The Safety Analysis Set included all participants who received at least 1 dose of study treatment.

irAEs were monitored throughout the study as per National Comprehensive Cancer Network® (NCCN) guidelines. irAEs were defined as any Grade ≥3 event that did not resolve to Grade 1 (or baseline) within 7 days from the onset of the event, or any Grade ≥3 organ toxicity involving major organ systems that persisted for greater than 72 hours.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=7 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Number of Participants With Immune-related Adverse Events (irAEs)	1 Participants

PRIMARY outcome

Timeframe: Up to approximately 6 months

Population: The evaluable analysis set included all participants who received at least 1 administration of study treatment and had an evaluable baseline tumor assessment and had at least one evaluable post-baseline tumor response assessment as per RECIST v1.1, or were discontinued due to toxicity.

Objective response was defined as the number of participants achieving a confirmed best overall response of complete response (CR) or partial response (PR) according to Response Evaluation Criteria for Solid Tumors, Version 1.1 (RECIST v1.1). * CR: Disappearance of all target lesions. * PR: At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=5 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Number of Participants With Objective Response	0 Participants

SECONDARY outcome

Timeframe: Up to approximately 6 months

Overall Survival (OS) was defined as the time from first dose of study drug to death due from any cause.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=5 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Overall Survival (OS)	NA months OS could not be calculated due to insufficient number of events.

SECONDARY outcome

Timeframe: Up to approximately 6 months

PFS was defined as the time from first dose of study drug to first documentation of progressive disease (PD) based on RECIST 1.1, or to death from any cause. PD: At least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=5 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Progression Free Survival (PFS)	NA months PFS could not be calculated due to insufficient number of events.

SECONDARY outcome

Timeframe: Up to approximately 6 months

DoR was measured from earliest CR or PR until first documentation of PD based on RECIST 1.1 or death due to any cause.

Outcome measures

Outcome measures
Measure	IMU-131 + Pembrolizumab n=5 Participants Participants received IMU-131 IM on Day 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Duration of Response (DoR)	NA months DoR could not be calculated due to insufficient number of events.

Adverse Events

IMU-131 + Pembrolizumab

Serious events: 0 serious events

Other events: 6 other events

Deaths: 6 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	IMU-131 + Pembrolizumab n=7 participants at risk Participants received IMU-131 IM on Days 1, 15, 29 and 57 and then every 63 days until disease progression or treatment discontinuation. Pembrolizumab was administered Q3W starting on Day 1 until disease progression or treatment discontinuation.
Gastrointestinal disorders Abdominal pain	28.6% 2/7 • First dose of study drug up to approximately 1.5 years
Gastrointestinal disorders Ascites	28.6% 2/7 • First dose of study drug up to approximately 1.5 years
Gastrointestinal disorders Constipation	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Gastrointestinal disorders Nausea	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Gastrointestinal disorders Vomiting	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
General disorders Fatigue	28.6% 2/7 • First dose of study drug up to approximately 1.5 years
General disorders Pain	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Metabolism and nutrition disorders Decreased appetite	28.6% 2/7 • First dose of study drug up to approximately 1.5 years
Metabolism and nutrition disorders Hyponatraemia	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Musculoskeletal and connective tissue disorders Back pain	28.6% 2/7 • First dose of study drug up to approximately 1.5 years
Musculoskeletal and connective tissue disorders Arthralgia	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Infections and infestations Oral candidiasis	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Investigations Blood bilirubin increased	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Nervous system disorders Brain oedema	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Nervous system disorders Cognitive disorder	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Nervous system disorders Speech disorder developmental	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Psychiatric disorders Agitation	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Psychiatric disorders Anxiety	14.3% 1/7 • First dose of study drug up to approximately 1.5 years
Skin and subcutaneous tissue disorders Rash	14.3% 1/7 • First dose of study drug up to approximately 1.5 years

Additional Information

Study Director

Imugene

Phone: +61 2 9423 0881

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place