A randomized, double-blind phase I clinical trial of two recombinant dimeric RBD COVID-19 vaccine candidates: Safety, reactogenicity and immunogenicity.

BACKGROUND: The Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is the target for many COVID-19 vaccines. Here we report results for phase I clinical trial of two COVID-19 vaccine candidates based on recombinant dimeric RBD (d-RBD). METHODS: We performed a randomized, double-blind, phase I clinical trial in the National Centre of Toxicology in Havana. Sixty Cuban volunteers aged 19-59 years were randomized into three groups (20 subjects each): 1) FINLAY-FR-1 (50 µg d-RBD plus outer membrane vesicles from N. meningitidis); 2) FINLAY-FR-1A-50 (50 µg d-RBD, three doses); 3) FINLAY-FR-1A-25 (25 µg d-RDB, three doses). The FINLAY-FR-1 group was randomly divided to receive a third dose of the same vaccine candidate (homologous schedule) or FINLAY-FR-1A-50 (heterologous schedule). The primary outcomes were safety and reactogenicity. The secondary outcome was vaccine immunogenicity. Humoral response at baseline and following each vaccination was evaluated using live-virus neutralization test, anti-RBD IgG ELISA and in-vitro neutralization test of RBD:hACE2 interaction. RESULTS: Most adverse events were of mild intensity (63.5%), solicited (58.8%), and local (61.8%); 69.4% with causal association with vaccination. Serious adverse events were not found. The FINLAY-FR-1 group reported more subjects with adverse events than the other two groups. After the third dose, anti-RBD seroconversion was 100%, 94.4% and 90% for the FINLAY-FR-1, FINLAY-FR-1A-50 and FINLAY-FR-1A-25 respectively. The in-vitro inhibition of RBD:hACE2 interaction increased after the second dose in all formulations. The geometric mean neutralizing titres after the third dose rose significantly in the group vaccinated with FINLAY-FR-1 with respect to the other formulations and the COVID-19 Convalescent Serum Panel. No differences were found between FINLAY-FR-1 homologous or heterologous schedules. CONCLUSIONS: Vaccine candidates were safe and immunogenic, and induced live-virus neutralizing antibodies against SARS-CoV-2. The highest values were obtained when outer membrane vesicles were used as adjuvant. TRIAL REGISTRY: https://rpcec.sld.cu/en/trials/RPCEC00000338-En.

Nasal administration of the neuroprotective candidate NeuroEPO to healthy volunteers: a randomized, parallel, open-label safety study.

BACKGROUND: Delivery of therapeutic agents as erythropoietin (EPO) into Central Nervous System through intranasal route could benefit patients with neurological disorders. A new nasal formulation containing a non-hematopoietic recombinant EPO (NeuroEPO) has shown neuroprotective actions in preclinical models. In the current study, the safety of NeuroEPO was evaluated for the first time in humans. METHODS: A phase I, randomized, parallel, open-label study was carried out in healthy volunteers. They received, intranasally, 1 mg of NeuroEPO every 8 h during 4 days (Group A) or 0.5 mg of NeuroEPO (Group B) with the same schedule. The working hypothesis was that intranasal NeuroEPO produce <10% of severe adverse reactions in the evaluated groups. Therefore, a rigorous assessment of possible adverse events was carried out, which included tolerance of the nasal mucosa and the effect on hematopoietic activity. Clinical safety evaluation was daily during treatment and laboratory tests were done before and on days 5 and 14 after starting treatment. RESULTS: Twenty-five volunteers, 56% women, with a mean age of 27 yrs. were included. Twelve of them received the highest NeuroEPO dose. Twenty types of adverse events occurred, with headache (20%) and increase of hepatic enzymes (20%) as the most reported ones. Nasopharyngeal itching was the most common local event but only observed in four patients (16%), all of them from the lowest dose group. About half of the events were very probably or probably caused by the studied product. Most of the events were mild (95.5%), did not require treatment (88.6%) and were completely resolved (81.8%). No severe adverse events were reported. During the study the hematopoietic variables were kept within reference values. CONCLUSIONS: NeuroEPO was a safe product, well tolerated at the nasal mucosa level and did not stimulate erythropoiesis in healthy volunteers. TRIAL REGISTRATION: Cuban Public Registry of Clinical Trials RPCEC00000157 , June 10, 2013.

Pharmacokinetic and pharmacodynamic characterization of a novel formulation containing co-formulated interferons alpha-2b and gamma in healthy male volunteers.

BACKGROUND: More potent antitumor activity is desired in Interferon (IFN)-treated cancer patients. This could be achieved by combining IFN alpha and IFN gamma. The aim of this work was to characterize the pharmacokinetics and pharmacodynamics of a novel formulation containing a co-formulated combination of IFNs alpha-2b and gamma (CIGB-128-A). METHODS: A group of nine healthy male subjects received intramuscularly 24.5 × 106 IU of CIGB-128-A. IFN concentrations were evaluated for 48 h. Serum neopterin, beta2-microglobulin (ß2M) and 2'-5' oligoadenylate synthetase (2'-5' OAS), classical IFN-inducible serum markers, were measured during 192 h by enzyme immunoassay and body temperature was used as pharmacodynamic variable as well. RESULTS: Concerning pharmacokinetics, serum IFNs' profiles were better fitted to a mono-compartmental model with consecutive zero order and first order absorption, one bioavailability value. No interferences by simultaneous administered IFNs were observed in their typical similar systemic profiles. Neopterin and ß2M time profiles showed a delay that was efficiently linked to pharmacokinetics by means of a zero order absorption rate constant. Neopterin level was nine-fold higher than initial values, 48 h post-administration, an increment not described before. At this time, mean serum ß2M peaked around the double from baseline. Serum concentrations of the enzyme 2'-5' OAS was still elevated on the 8 day post-injection. The formulation was well tolerated. Most frequent adverse reactions were fever, headache, arthralgia and lymphopenia, mostly mild. CONCLUSIONS: The administration of co-formulated IFN alpha-2b and IFN gamma likely provides improved pharmacodynamic properties that may be beneficial to treat several malignancies. TRIAL REGISTRATION: Cuban Public Registry of Clinical Trials RPCEC00000118 , May 24, 2011.