CureVac touts COVID-19 vax data as platform validation, despite grade 3 adverse events

CureVac says its monovalent and bivalent COVID-19 vaccine candidates produced meaningful immune responses at lower doses than similar approved vaccines and were generally safe—though grade 3 adverse events were recorded in a few of the health volunteers. 

The phase 2 study is evaluating a single booster dose of a monovalent vaccine candidate called CV0601, which encodes the spike protein of the omicron BA.4-5 variant, and three different dose levels of a bivalent candidate dubbed CV0701, which encodes the spike protein of the omicron BA.4-5 variant and original SARS-CoV-2 virus. CureVac's shots were compared to an unnamed, approved bivalent mRNA-based COVID-19 vaccine in healthy volunteers. 

All dosing levels of CureVac’s GSK-partnered mRNA vaccines fall below those used in mRNA COVID-19 vaccines approved in the U.S. and EU, such as Moderna’s Spikevax or Pfizer-BioNTech’s Comirnaty.

CureVac detailed an interim readout from the trial Friday, saying that the vaccines were generally well tolerated, “with a lower or similar proportion of participants reporting solicited adverse events when compared to comparator vaccine participants within seven days of dosing.”

Among 87 healthy participants receiving the CV0701 low dose, 1% had a grade 3 adverse event (AE)—which are considered severe or medically significant but not immediately life-threatening. For 84 participants receiving the middle dose, 2% had a grade 3 AE, while no grade 3 or above AEs occurred in the highest CV0701 dosing group, according to a presentation accompanying the press release.

No grade 3 events or higher were reported among the 85 participants in the comparator vaccine group.

The data showed meaningful titers of neutralizing antibodies for both candidates at all dose levels, according to CureVac. Titers of neutralizing antibodies matched or exceeded those induced by the comparator vaccine at all tested doses except for the lowest dose level of CV0701.

“These positive phase 2 data continue to strongly validate the competitiveness of our proprietary mRNA-technology platform and second-generation mRNA backbone in comparison to a licensed mRNA-based vaccine,” Myriam Mendila, M.D., chief development officer of CureVac, said in a Jan. 5 release. “We are greatly encouraged by the strong immunogenicity results achieved for our COVID-19 mRNA vaccine candidates and are in advanced discussions with regulatory authorities to determine the best path forward for a pivotal phase 3 study.”

The company is also advancing an mRNA flu vaccine program in partnership with GSK as well. The Big Pharma first signed the mRNA deal with CureVac in July 2020 in the first months of the global COVID-19 pandemic.

The German biotech also awaits a decision on several patent infringement lawsuits against BioNTech. CureVac claims BioNTech violated certain patents with the rapid creation of its megablockbuster COVID-19 vaccine, in partnership with Pfizer.