Trial Outcomes & Findings for A Phase 2 Influenza A Challenge Study Following Oral Administration of an H1N1 HA Ad-Vector Seasonal Flu Vaccine (NCT NCT02918006)

Last Updated: 2022-10-06

Results Overview

The clinical efficacy of VXA-A1.1 to protect against illness caused by the homologous A strain influenza virus with challenge 3 months following a single immunization in comparison to placebo and QIV. Participants were evaluated for clinical signs and symptoms of influenza as well as for viral shedding via PCR for confirmation of infection.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

179 participants

Primary outcome timeframe

Clinical Illness and/or laboratory confirmed infection occurring following viral challenge at 3 months post vaccination

Results posted on

2022-10-06

Participant Flow

Between Aug 31, 2016, and Jan 23, 2017, 374 individuals were assessed for eligibility.

Participant milestones

Participant milestones
Measure	Oral Vaccine (VXA-A1.1) Oral enteric coated vaccine tablets. Placebo (saline solution) IM injection was also administered in this arm. VXA-A1.1: Enteric coated oral vaccine tablet Saline Solution for Placebo IM Injection	QIV IM Injection A commercially available QIV was administered at the approved dose level as the active comparator. Oral placebo tablets were also administered in this arm. Fluzone®: Fluzone Quadravalent (Fluzone®) influenza vaccine (QIV) suspension for intramuscular (IM) injection Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product	Oral and IM Placebo Two forms of placebo (saline IM injection and oral placebo tablets) were administered in this arm. Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product Saline Solution for Placebo IM Injection
Allocation and Follow-Up STARTED	71	72	36
Allocation and Follow-Up COMPLETED	69	70	35
Allocation and Follow-Up NOT COMPLETED	2	2	1
Vaccination Phase Analysis STARTED	69	70	35
Vaccination Phase Analysis COMPLETED	58	54	31
Vaccination Phase Analysis NOT COMPLETED	11	16	4
Challenge Phase Analysis STARTED	58	54	31
Challenge Phase Analysis COMPLETED	58	54	29
Challenge Phase Analysis NOT COMPLETED	0	0	2

Reasons for withdrawal

Reasons for withdrawal
Measure	Oral Vaccine (VXA-A1.1) Oral enteric coated vaccine tablets. Placebo (saline solution) IM injection was also administered in this arm. VXA-A1.1: Enteric coated oral vaccine tablet Saline Solution for Placebo IM Injection	QIV IM Injection A commercially available QIV was administered at the approved dose level as the active comparator. Oral placebo tablets were also administered in this arm. Fluzone®: Fluzone Quadravalent (Fluzone®) influenza vaccine (QIV) suspension for intramuscular (IM) injection Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product	Oral and IM Placebo Two forms of placebo (saline IM injection and oral placebo tablets) were administered in this arm. Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product Saline Solution for Placebo IM Injection
Allocation and Follow-Up Lost to Follow-up	1	2	1
Allocation and Follow-Up Withdrawal by Subject	1	0	0
Vaccination Phase Analysis Withdrawal by Subject	3	7	2
Vaccination Phase Analysis Biofire Positive	5	5	0
Vaccination Phase Analysis Symptoms of Sinusitis	1	0	0
Vaccination Phase Analysis Exlcuded by Investigator for Safety of Compliance	2	3	2
Vaccination Phase Analysis Seasonal allergies	0	1	0
Challenge Phase Analysis Withdrawal by Subject	0	0	1
Challenge Phase Analysis Lost to Follow-up	0	0	1

Baseline Characteristics

A Phase 2 Influenza A Challenge Study Following Oral Administration of an H1N1 HA Ad-Vector Seasonal Flu Vaccine

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Oral Vaccine (VXA-A1.1) n=71 Participants Oral enteric coated vaccine tablets. Placebo (saline solution) IM injection was also administered in this arm. VXA-A1.1: Enteric coated oral vaccine tablet Saline Solution for Placebo IM Injection	QIV IM Injection n=72 Participants A commercially available QIV was administered at the approved dose level as the active comparator. Oral placebo tablets were also administered in this arm. Fluzone®: Fluzone Quadravalent (Fluzone®) influenza vaccine (QIV) suspension for intramuscular (IM) injection Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product	Oral and IM Placebo n=36 Participants Two forms of placebo (saline IM injection and oral placebo tablets) were administered in this arm. Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product Saline Solution for Placebo IM Injection	Total n=179 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Age, Categorical Between 18 and 65 years	71 Participants n=5 Participants	72 Participants n=7 Participants	36 Participants n=5 Participants	179 Participants n=4 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Sex: Female, Male Female	29 Participants n=5 Participants	29 Participants n=7 Participants	15 Participants n=5 Participants	73 Participants n=4 Participants
Sex: Female, Male Male	42 Participants n=5 Participants	43 Participants n=7 Participants	21 Participants n=5 Participants	106 Participants n=4 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	24 Participants n=5 Participants	21 Participants n=7 Participants	10 Participants n=5 Participants	55 Participants n=4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	47 Participants n=5 Participants	48 Participants n=7 Participants	26 Participants n=5 Participants	121 Participants n=4 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	3 Participants n=7 Participants	0 Participants n=5 Participants	3 Participants n=4 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants
Race (NIH/OMB) Asian	8 Participants n=5 Participants	8 Participants n=7 Participants	4 Participants n=5 Participants	20 Participants n=4 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	1 Participants n=4 Participants
Race (NIH/OMB) Black or African American	14 Participants n=5 Participants	16 Participants n=7 Participants	7 Participants n=5 Participants	37 Participants n=4 Participants
Race (NIH/OMB) White	45 Participants n=5 Participants	45 Participants n=7 Participants	24 Participants n=5 Participants	114 Participants n=4 Participants
Race (NIH/OMB) More than one race	3 Participants n=5 Participants	3 Participants n=7 Participants	0 Participants n=5 Participants	6 Participants n=4 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Hemagglutination Inhibition (HAI) Titer	54 participants n=5 Participants	49 participants n=7 Participants	29 participants n=5 Participants	132 participants n=4 Participants

PRIMARY outcome

Timeframe: Clinical Illness and/or laboratory confirmed infection occurring following viral challenge at 3 months post vaccination

Population: Subjects that did not complete the vaccination phase per protocol criteria, did not undergo viral challenge, did not have Biofire results positive for infections other than influenza or were discharged early from the isolation unit post challenge were excluded from the per protocol analysis set.

Outcome measures

Outcome measures
Measure	Oral Vaccine (VXA-A1.1) n=58 Participants Oral enteric coated vaccine tablets. Placebo (saline solution) IM injection was also administered in this arm. VXA-A1.1: Enteric coated oral vaccine tablet Saline Solution for Placebo IM Injection	QIV IM Injection n=54 Participants A commercially available QIV was administered at the approved dose level as the active comparator. Oral placebo tablets were also administered in this arm. Fluzone®: Fluzone Quadravalent (Fluzone®) influenza vaccine (QIV) suspension for intramuscular (IM) injection Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product	Oral and IM Placebo n=31 Participants Two forms of placebo (saline IM injection and oral placebo tablets) were administered in this arm. Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product Saline Solution for Placebo IM Injection
Number of Subjects With Influenza-like Clinical Illness and Laboratory Confirmed Infection Post Challenge With a Homologous A Strain Influenza Virus	17 Participants	19 Participants	15 Participants

Adverse Events

Oral Vaccine (VXA-A1.1)

Serious events: 0 serious events

Other events: 15 other events

Deaths: 0 deaths

QIV IM Injection

Serious events: 0 serious events

Other events: 11 other events

Deaths: 0 deaths

Oral and IM Placebo

Serious events: 0 serious events

Other events: 4 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Oral Vaccine (VXA-A1.1) n=71 participants at risk Oral enteric coated vaccine tablets. Placebo (saline solution) IM injection was also administered in this arm. VXA-A1.1: Enteric coated oral vaccine tablet Saline Solution for Placebo IM Injection	QIV IM Injection n=72 participants at risk A commercially available QIV was administered at the approved dose level as the active comparator. Oral placebo tablets were also administered in this arm. Fluzone®: Fluzone Quadravalent (Fluzone®) influenza vaccine (QIV) suspension for intramuscular (IM) injection Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product	Oral and IM Placebo n=36 participants at risk Two forms of placebo (saline IM injection and oral placebo tablets) were administered in this arm. Placebo Tablets: Placebo tablets similar in size, color and number to the active oral tablet vaccine drug product Saline Solution for Placebo IM Injection
Infections and infestations Upper Respiratory Infection	15.5% 11/71 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.	9.7% 7/72 • Number of events 7 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.	11.1% 4/36 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.
Endocrine disorders Headache	5.6% 4/71 • Number of events 4 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.	5.6% 4/72 • Number of events 4 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.	0.00% 0/36 • Systemic and local solicited adverse events were collected daily through Day 8 post-vaccination Unsolicited AEs were recorded through 120 days post-vaccination (90 days in Part A and 30 days post challenge in Part B) SAEs and AESIs/NOCIs are recorded through Day 365 Systemic and local solicited adverse events were graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe) Systemic events include: diarrhea, nausea, vomiting, abdominal pain, malaise, anorexia, headache, myalgia and fever. Local events include injection site reactions of: pain, tenderness, erythema, and induration.

Additional Information

Sean Tucker, PhD, Chief Scientific Officer

Vaxart, Inc.

Phone: 650-550-3502

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place