Jim Wassil
Analyst · Bank of America. Your line is now open
Thanks, Grant. Before I get into our accomplishments for VAX-24 and status update, I think it would be helpful to review the manufacturing process for this program and the remaining activities necessary to enable the IND application submission. As we previously shared, the manufacturing process for VAX-24 included the following four steps. First, we manufacture eCRM, our proprietary protein carrier. Second, we manufacture 24 pneumococcal polysaccharides, one for each of the serotypes included in VAX-24. Third, we manufacture 24 conjugated drug substances, which consist of three discrete stages; first, each of the 24 polysaccharides to size to a targeted molecular weight, then a leaker is attached to each of the 24 sized polysaccharides to generate 24 activated polysaccharides. And finally, the 24 activated polysaccharides are conjugated or covalently linked to the eCRM carrier protein resulting in the 24 conjugated drug substances. The fourth and final step of the process includes manufacturing of the drug product by mixing the 24 conjugated drug substances and filling into vials. To-date, we’ve made significant progress towards our IND filing, including a number of key accomplishments in the past year. We’ve successfully completed the GMP manufacturer testing and release of both the eCRM carrier protein and the 24 pneumococcal polysaccharides. For the conjugated drug substance, we’ve now successfully sized and activated each of the 24 polysaccharides and are in the midst of the manufacturing of each of the 24 conjugated drug substances. Earlier this year, we successfully manufactured our initial drug product batches with our 24 conjugate at Lonza. These batches will serve as the source of our lead block stability data for our IND. We also successfully completed manufacturing of drug product batches used in the GLP toxicology studies, and initiated the GLP toxicology study in the first quarter of this year. Now, before we submit our IND, we still have a few outstanding items, which include, first, completion of the GMP manufacturing testing and release of the conjugated drug substances and drug product; second, completion of the GLP toxicology study that is currently underway; and third, generation and submission of stability data resulting from the GMP drug product. As Grant mentioned, we’re updating our guidance for the VAX-24 IND submission as a result of a few factors, which I will provide more detail on. First, as we have progressed through the manufacturing of the 24 drug substances, we experienced some process-related issues as we transitioned into GMP production at Lonza. In and of themselves, these only cause minor delays across the three stages of production, but taken together have resulted in a meaningful cumulative delay to the campaign. While these adjustments are typical for this stage of the vaccine development and our initial guidance has accounted for process modifications, we underestimated the cumulative impact of these changes. As I noted, we have now progressed successfully through the first two stages of the drug substance production campaign, and are in the midst of the final stage of conjugating the 24 drugs substances. Ultimately, before we were able to complete the final conjugation stage, we encountered an interruption of the drug substance manufacturing campaign at Lonza, now working with a world-class team of such as Lonza has many benefits. However, they also have numerous clients with late stage clinical and commercial products. As a result, our GMP conjugate manufacturing campaign was unfortunately interrupted due to Lonza’s prior customer commitments. The good news is that we have resumed our manufacturing campaign, the early data of which are encouraging and working towards completing the 24 conjugated drugs substances. Finally, the COVID-19 pandemic created some operational headwinds, travel restrictions delayed the qualification of key analytical equipment and in-person CMO oversight. We also saw raw material supply chain slowed. Fortunately, we do believe these issues have now been resolved. All in all, we have made substantial progress towards delivering the VAX-24 IND and look forward to completing the remaining deliverables for our current guidance. As previously noted, we’re also announcing today New Immunogenicity Data for our VAX-XP, our PCV candidate with expanded breadth of coverage of at least 30 strains, the strains in VAX-XP cover over 90% of invasive pneumococcal disease currently circulating in the United States. The new data demonstrates the potential scalability and robustness of our technology platform. Importantly, they also demonstrate that during the scale-up and transfer to Lonza, the fidelity of the process was maintained. In this study conducted in rabbits, we compared VAX-XP to more than 30 different pneumococcal serotypes including all those contained in Prevnar 13. The results show that VAX-XP immuneresponses were at least comparable to Prevnar 13 and superior to polysaccharide only serotypes like those contained in Pneumovax 23. Before turning it over to Jeff to provide an update on the status of VAX-A1, a prophylactic vaccine candidate designed to prevent Group A Strep infections, I want to touch upon the increasing global need for vaccine to address the series pathogen. Group A Strep is a ubiquitous disease causing an estimated 700 million cases of disease globally. The majority of these are pharyngitis, or strep throat, which result in significant usage of antibiotic prescriptions, and consequently are a source of increased antibiotic resistance. Group A Strep can also have grave outcomes. There are an estimated half a million deaths per year globally due to the combination of rheumatic heart disease and other invasive diseases. But traditionally thought of as a childhood disease, the rate of invasive disease in the elderly has increased substantially over the past decade. In the U.S., the SV rate of invasive disease in adults 65 and over has more than doubled since 2012. And it's now more than three times the rate of invasive pneumococcal disease when the CDC recommended Prevnar 13 for the adult population. This creates an opportunity to develop VAX-A1 not only for children, but also adults. We believe VAX-A1 has first-in-class and best-in-class potential to address this significant need. With that, I'll turn it over to Jeff to provide a program update.