Clover Bio-B (02197) Announces Respiratory Combination Vaccine Candidate (RSV + hMPv ± PIV3) Receives Positive Data in Australian Phase II Clinical Trials in the Elderly

Zhitong Finance App News, Clover Bio-B (02197) announced positive preliminary data from a phase II clinical trial conducted in the elderly population in Australia. The test was used to evaluate SCB1022 (rSV+hMPv) and SCB-1033 (rSV+hMPv+pIV3) protein vaccine candidates. The antigen is a trimeric subunit vaccine antigen based on stabilized F protein (PrEF) before fusion, using Trimer-Tag (protein trimer) vaccine development platform validated by Clover Biology.

The ongoing phase II clinical trial of the Clover biological combination vaccine candidate is a randomized, observer-blind, multi-center study. A total of 420 elderly subjects (aged 60-85) were enrolled in Australia. The subjects were randomly assigned to receive SCB-1022 (rSV+hmpV), SCB1033 (RSV+hmpV), or placebo.

immunogenicity

The antibody titer (geometric mean titer “GMT”) after 28 days of vaccination in the phase II clinical trial was generally similar to or higher than the previous phase I clinical trial.

Compared with before vaccination, the mean doubling rate (GMFR) of neutralizing antibodies (nAbs) after 28 days of vaccination: ORSV neutralizing antibodies: increased by about 6-9 times OhMPV neutralizing antibodies: about 6-8 times higher for opIv3 neutralizing antibodies: 3 times higher (approximately 5 times higher in subjects with baseline PIV3 neutralizing antibody levels in the lowest three digits), driven by a 20-fold increase in PIV3 PrEF-specific antibodies.

Compared to younger subjects (60-74 years), no decrease in antibody response was observed in the oldest subjects (75 years and over).

Compared with SCB-1022 (RSV+hMPv), no immune interference with RSV and HMPV neutralizing antibodies was observed with the new PIV3 PrEF antigen in SCB-1033 (RSV+hMPv+PIV3).

Respiratory tract infections (based on reports of adverse events):

Based on reports of any adverse events of respiratory infections (infected cases were not PCR sequenced in this study), the incidence of respiratory infections in the vaccine group (SCB-1022 and SCB-1033) was about 62% lower than in the placebo group within 28 days after vaccination.

A significant seasonal outbreak of RSV occurred in Australia during study enrollment and follow-up, accompanied by a co-epidemic of HMPV and PiV.

Safety and reactogenicity

SCB-1022 and SCB-1033 were generally well tolerated; most of the collected local and systemic adverse events (AEs) within 7 days of vaccination were mild and all transient. The most common adverse events were fatigue, headache, and pain at the injection site. The average duration of the vaccine group (SCB-1022 and SCB-1033) and the placebo group was about 2 days.

Within 28 days of vaccination, the frequency of non-conscripted adverse events (AEs) was similar between the vaccine group and the placebo group.

There were no reports of serious adverse events (SAEs) associated with the vaccine, adverse events of special interest (AESIs), or adverse events (AEs) that led to the discontinuation of the trial.

Expansion of commercial-scale production:

At the same time as the phase II clinical trial, Clover Biotech carried out large-scale production of 2000 liter bioreactors with RSV, HMPV, and PIV3 PrEF antigen components (trimer-tag trimer) in SCB-1022/1033, and completed multiple batches.

The successful scaling up of the 2,000 litre production process further reduced the risk of future later development and commerce).

The above positive phase II clinical trial results based on the RSV+hmpv± PIV3 vaccine candidate product further validated the Trimer-tag platform, and Clover Biotech will continue to evaluate subsequent medium- and late-stage development plans and potential international cooperation opportunities to achieve the greatest value).