Evaluating the Equivalence of the Vaccine Preparations
The equivalence of products produced for POC trials and for ASD was evaluated using molecular characterization, biological
activity in mice, and clinical data from administration to patients with advanced lung cancer.
To demonstrate equivalence through molecular characterization, the biologically active moieties (rEGF–rP64k conjugated species)
of both products (for POC and ASD) were analyzed by peptide mapping, following digestion of the conjugated rEGF-rP64k fractions
with the endoprotease Glu-C. Each fraction of the resulting maps was identified and sequenced by mass spectrometry. Figure
5 shows the peptide maps of the rEGF–rP64k conjugated species from A) the product made for POC and B) the product made for
ASD. A high degree of similarity is seen in the peptide profiles and their relative amounts, indicating the equivalence of
the products in terms of the structure of their biologically active moieties (rEGF–rP64k conjugated species).
Figure 5. Peptide maps of chromatographic fractions corresponding to the conjugated rEGF-rP64k (active moieties) from (A)
product made for proof-of-concept trials and (B) product made for advanced stages of development.
Figure 6 shows biological activity using measurements of anti-rEGF antibody response in mice for the POC and the ASD vaccine
preparations. No statistically significant differences were observed.
Figure 6. Comparison of the immunogenic activity test results obtained after immunizing mice with vaccine preparations for
proof-of-concept (POC) trials and for advanced stages of development (ASD). Each bar represents the mean optical density
from an ELISA assay performed on eight lots of vaccine. Different sera dilutions were tested (1:100, 1:1,000 and 1:10,000).
The clinical performance of both products was also evaluated in advanced lung cancer patients. Clinical data from eight patients
vaccinated with each vaccine preparation were compared (Figure 7). As can be observed, there were no significant differences
in the anti-rEGF antibody titers obtained when immunizing patients with the vaccine for POC and with the vaccine for ASD,
demonstrating an equivalent immunological effect in humans.
Figure 7. Anti-EGF antibody responses in patients vaccinated with the preparations made for proof-of-concept (POC) trials
and advanced stages of development (ASD). Y axis represents the geometric means of anti-EGF antibody titers; bars represent
the geometric mean of antibody titers in eight patients vaccinated with the two different products. The line represents the
geometric mean of anti-EGF antibody in time for control sera (unvaccinated patients).
The initial limitations of the manufacturing process used for proof of concept studies of the CIMAvax-EGF vaccine were overcome
by a process development strategy that focused on scalability and GMP requirements. The new in-process tests and end-product
testing showed acceptable consistency and comparability. The vaccine preparation obtained following the manufacturing improvements
showed similar clinical performance compared to the product used during the proof-of-concept trials.
GRYSSELL RODRIGUEZ is the CIMAvax-EGF manufacturing manager, AIRAMA ALBISA is a process development scientist, LISEL VIÑA is the CIMAvax-EGF quality control manager, ARIADNA CUEVAS is the CIMAvax-EGF regulatory affairs manager, BEATRIZ GARCIA is a clinical researcher, AURORA TAMARA GARCIA is the CIMAvax-EGF quality assurance manager, ALEJANDRO PORTILLO is a quality control specialist, LOANY CALVO is a quality control specialist, TANIA CROMBET is the clinical research director, and ERNESTO CHICO is the technical director, all at the Centro de Inmunología Molecular (Center for Molecular Immunology), Havana, Cuba, email@example.com
, +53-7 2716810. GISELA GONZALEZ is the business development manager at CIMAB SA, Havana, Cuba.