Billionaire German investor Dietmar Hopp is betting another €80 million ($105 million) on CureVac, a pioneer of vaccines based on a molecule related to DNA, in one of the biggest financings for a private European biotech company.

Hopp, a co-founder of software group SAP, is a major player in the biotech space and has a mission to revitalise the German sector, which has struggled to recover since the implosion of several listed companies a decade ago.

He is also the key backer of soccer club Hoffenheim.

The cash injection keeps Hopp as sole owner of CureVac, which was spun out of Tuebingen University 12 years ago to develop vaccines against cancer and infectious diseases using messenger RNA (mRNA) - a single-stranded molecule related to DNA.

The company's most advanced product is a therapeutic vaccine for prostate cancer, which is about to start a lengthy Phase IIb clinical trial that will test whether it can improve overall survival.

CureVac's chief executive, Ingmar Hoerr, said the new money - which brings total equity funding to date to €145 million - would pay for operations at least until the results of this test are received in 2017.

The prostate cancer vaccine, CV9103, is still a long way from approval and it will be jockeying for position in an increasingly crowded market for drugs and other therapeutic vaccines, which work by boosting the body's immune system.

U.S. biotech group Dendreon's Provenge became the first vaccine for prostate cancer to be launched two years ago, although sales since then have been disappointing.

Hoerr said complex diseases like prostate cancer needed different treatments at different stages. "This is the way we have to go to make a chronic disease out of cancer," he said.

CureVac also has a vaccine for non-small cell lung cancer in development and, additionally, is working on prophylactic vaccines against several unnamed infectious diseases in a collaboration with Sanofi.

Using mRNA to develop vaccines is an unusual approach in the pharmaceuticals industry and RNA's inherent instability has deterred researchers in the past. CureVac, however, believes its technology platform has overcome these problems.