Influence of human serum albumin content in formulations on the bioequivalency of interferon alfa-2a given by subcutaneous injection in healthy male volunteers

Integration of healthy volunteers in early phase clinical trials with immuno-oncological compounds

Aim

Traditionally, early phase clinical trials in oncology have been performed in patients based on safety risk-benefit assessment. Therapeutic transition to immuno-oncology may open new opportunities for studies in healthy volunteers, which are conducted faster and are less susceptible to confounders. Aim of this study was to investigate to what extent this approach is utilized and whether pharmacodynamic endpoints are evaluated in these early phase trials. We conducted a comprehensive review of clinical trials with healthy volunteers using immunotherapies potentially relevant for oncology.

Methods

Literature searches according to PRISMA guidelines and after registration in PROSPERO were conducted in PubMed, Embase, Web of Science and Cochrane databases with the cut-off date 20 October 2020, using search terms of relevant targets in immuno-oncology. Articles describing clinical trials with immunotherapeutics in healthy volunteers with a mechanism relevant for oncology were included. “Immunotherapeutic” was defined as compounds exhibiting effects through immunological targets. Data including study design and endpoints were extracted, with specific attention to pharmacodynamic endpoints and safety.

Results

In total, we found 38 relevant immunotherapeutic compounds tested in HVs, with 86% of studies investigating safety, 82% investigating the pharmacokinetics (PK) and 57% including at least one pharmacodynamic (PD) endpoint. Most of the observed adverse events (AEs) were Grade 1 and 2, consisting mostly of gastrointestinal, cutaneous and flu-like symptoms. Severe AEs were leukopenia, asthenia, syncope, headache, flu-like reaction and liver enzymes increase. PD endpoints investigated comprised of cytokines, immune and inflammatory biomarkers, cell counts, phenotyping circulating immune cells and ex vivo challenge assays.

Discussion

Healthy volunteer studies with immuno-oncology compounds have been performed, although not to a large extent. The integration of healthy volunteers in well-designed proof-of-mechanism oriented drug development programs has advantages and could be pursued more in the future, since integrative clinical trial protocols may facilitate early dose selection and prevent cancer patients to be exposed to non-therapeutic dosing regimens.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=210861, identifier CRD42020210861

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 (β₂M) 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 β₂M 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 β₂M 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.

Isolation and characterization of serum albumin from Camelus dromedarius

Serum albumin constitutes 35–50 mg/ml of plasma proteins and performs various physiological activities including the regulation of osmotic pressure on blood, maintaining buffering of the blood pH, carrying different fatty acids and other small molecules, such as bilirubin, hormones, drugs and metal ions, as well as participating in immunological responses. Serum albumin is an extensively used protein in biotechnological and pharmaceutical industries. The camel (Camelus dromedarius) is well tailored to successfully survive in extremely hot and dry climates. Plasma osmolality in the camel increases during water-deprived conditions. In such circumstances serum albumin is crucial in the regulation of blood pressure. The study of biochemical, biophysical and immunological aspects of camel serum albumin (CSA) are likely to provide molecular insights into camel physiology and may render it an alternative to human serum albumin (HSA) and bovine serum albumin (BSA) in all cases. However, these proteins are currently not available or cannot be utilized due to a variety of considerations. In this study, 12 mg of highly pure CSA was obtained from 1 ml plasma. Coomassie Brilliant Blue staining of SDS-PAGE yielded one band and RP-HPLC results revealed a single sharp peak, indicating homogenous preparation of the CSA. The charge/mass ratio and surface hydrophobicity of the CSA was similar to that of BSA. Mass spectrometry analysis of the purified protein confirmed the identity of CSA.

Pharmacokinetic and pharmacodynamic characterization of a new formulation containing synergistic proportions of interferons alpha-2b and gamma (HeberPAG) in patients with mycosis fungoides: an open-label trial

Background

The synergistic combination of interferon (IFN) alpha-2b and IFN gamma results in more potent in vitro biological effects mediated by both IFNs. The aim of this investigation was to evaluate by first time the pharmacokinetics and pharmacodynamics of this combination in patients with mycosis fungoides.

Methods

An exploratory, prospective, open-label clinical trial was conducted. Twelve patients, both genders, 18 to 75 years-old, with mycosis fungoides at stages IB to III, were eligible for the study. All of them received intramuscularly a single high dose (23 × 10⁶ IU) of a novel synergistic IFN mixture (HeberPAG®) for pharmacokinetic and pharmacodynamic studies. Serum IFN alpha-2b and IFN gamma concentrations were measured during 96 hours by commercial enzyme immunoassays (EIA) specific for each IFN. Other blood IFN-inducible markers and laboratory variables were used as pharmacodynamics and safety criteria.

Results

The pharmacokinetic evaluation by EIA yielded a similar pattern for both IFNs that are also in agreement with the well-known described profiles for these molecules when these are administered separately. The average values for main parameters were: Cmax: 263 and 9.3 pg/mL; Tmax: 9.5 and 6.9 h; AUC: 4483 and 87.5 pg.h/mL, half-life (t_1/2): 4.9 and 13.4 h; mean residence time (MRT): 13.9 and 13.5 h, for serum IFN alpha-2b and IFN gamma, respectively. The pharmacodynamic variables were strongly stimulated by simultaneous administration of both IFNs: serum neopterin and beta-2 microglobulin levels (β₂M), and stimulation of 2’-5’ oligoadenylate synthetase (OAS1) mRNA expression. The most encouraging data was the high increment of serum neopterin, 8.0 ng/mL at 48 h, not been described before for any unmodified or pegylated IFN. Additionally, β₂M concentration doubled the pre-dose value at 24–48 hours. For both variables the values remained clearly upper baseline levels at 96 hours.

Conclusions

HeberPAG®possesses improved pharmacodynamic properties that may be very useful in the oncologic setting. Efficacy trials can be carried out to confirm these findings.

Trial registration

Registro Público Cubano de Ensayos Clínicos RPCEC00000130

Bioequivalence of two recombinant interferon alpha-2b liquid formulations in healthy male volunteers

OBJECTIVE

Interferon (IFN) alpha-2b is a protein with antiviral, antiproliferative and immunoregulatory properties that is approved for several clinical indications. A new liquid, albumin-free, IFNalpha-2b formulation has recently been developed. This study aimed to evaluate the equivalence of the pharmacokinetic, pharmacodynamic and safety properties of the new formulation with a reference one in healthy male volunteers.

METHODS

A randomised, crossover, double-blind study with a 3-week washout period was performed in which Heberon Alfa R (formulation A) and Viraferon (formulation B) were compared. A single 20 x 10(6) IU IFNalpha-2b dose was administered subcutaneously to 14 apparently healthy male subjects. Serum IFN level was measured over 48 hours by enzyme immunoassay (EIA) and by antiviral activity titration. Clinical and laboratory variables were determined, as were pharmacodynamic and safety criteria.

RESULTS

Groups were homogeneous with regard to all demographic and baseline variables. Pharmacokinetic comparison by EIA did not show differences between the formulations: area under the curve (AUC) 2572 versus 2561 ng x h/L, maximum plasma concentration (Cmax) 318 versus 354 ng/L, time to Cmax (tmax) 8.2 versus 8.5 h, elimination half-life (t(1/2)) 5.87 versus 6.08 h, terminal elimination rate (lambda) 0.122 versus 0.118 h(-1), and mean residence time (MRT) 10.9 versus 12.0 h for formulations A and B, respectively. The differences never reached 20%, which is the clinically significant threshold. The 90% confidence interval of the ratio between them was in all cases within the 0.8, 1.25 range. The two formulations were clinically equivalent with regard to serum IFN antiviral activity titration (0.8, 1.25 criterion) regarding their pharmacokinetic parameters. There were no significant differences with respect to the pharmacodynamic variables: serum beta2-microglobulin and temperature increase. Heart rate and blood pressure changes did not differ either. Both products provoked similar haematological count decreases and had similar safety profiles. The most frequent adverse reactions were fever, tachycardia, headache and arthralgias.

CONCLUSION

The overall analysis strongly suggests the bioequivalence of these two products.

Use of peginterferon alfa-2a (40 KD) (Pegasys) for the treatment of hepatitis C

Thrice-weekly interferon alfa-2b plus ribavirin has been the standard of care for chronic hepatitis C; however, a majority of patients fail to achieve a sustained virological response with this treatment. Peginterferon alfa-2a (40 KD), interferon alfa-2a conjugated to a 40 kDa branched polyethylene glycol moiety, exhibits sustained absorption and reduced renal clearance, resulting in antiviral pressure throughout a once-weekly dosing schedule. Peginterferon alfa-2a (40 KD) has superior virological efficacy to interferon alfa-2a, and elicits histological improvements in patients with and without sustained virological response. Peginterferon alfa-2a (40 KD) is effective in patients infected with viral genotype 1 and those with liver cirrhosis. Viral RNA measurements at 12 weeks can be used to predict the probability of achieving sustained virological response to peginterferon alfa-2a (40 KD) therapy. Peginterferon alfa-2a (40 KD) has comparable safety to interferon alfa-2a. The addition of ribavirin to peginterferon alfa-2a (40 KD) further enhances the therapeutic benefit for patients with hepatitis C.

Pegylated interferons: what role will they play in the treatment of chronic hepatitis C?

The primary therapy for patients with chronic hepatitis C virus (HCV) infection is interferon alfa. However, use of interferon for treatment of chronic HCV has several shortcomings that limit its effectiveness. Interferon has a very short half-life, must be administered multiple times weekly, and is associated with significant side effects. "PEGylation" is a process whereby the inert polymer, polyethylene glycol (PEG), is attached to a protein pharmaceutical. This process has been shown to alter the properties of PEGylated proteins in a manner that significantly extends half-life, reduces immunogenicity, and enhances biologic activity when compared with the native protein. In recent years, several PEGylated forms of interferon alfa have been developed. Recent studies have demonstrated that PEG-interferons have a significantly prolonged half-life and sustained virologic response when compared with standard interferon. Studies to evaluate the effects of combining PEG-interferons with ribavirin are currently underway. The role PEG-interferons will play in patients who have either relapsed or failed to respond to previous interferon or interferon/ribavirin therapy remains to be defined.

Use of an indirect pharmacodynamic stimulation model of MX protein induction to compare in vivo activity of interferon alfa-2a and a polyethylene glycol-modified derivative in healthy subjects

Interferon alfa-2a was chemically modified by the covalent attachment of a polyethylene glycol (PEG) moiety to enhance its circulating half-life and to reduce its immunogenicity. A comparative evaluation of the pharmacokinetics of the PEG-modified interferon alfa-2a showed a greater than twofold increase in the circulating half-life as a result of this chemical modification. An indirect physiologic response model was developed to characterize the time course of the MX protein response after subcutaneous administration of single ascending doses of either interferon alfa-2a or PEG-interferon alfa-2a in healthy volunteers. Analysis of the pharmacokinetic-pharmacodynamic relationship suggested that the PEG-modified interferon alfa-2a could not be administered less than twice weekly and therefore offered little therapeutic advantage over its unmodified counterpart, which is administered three times weekly. These results were consistent with findings in phase II trials. This study substantiates the usefulness of pharmacodynamic modeling as a tool for the development of dose recommendations and for the early selection of drug candidates in the drug development process.