Sanofi advances C. diff vaccine into PhIII

Sanofi Pasteur is entering an important period for its vaccine business. The success of its big bet on a dengue fever vaccine hangs on upcoming late phase data. And its clostridium difficile jab has just entered Phase III, too.

The C. diff trial is now enrolling 15,000 adults at 200 sites across 17 countries as Sanofi tries to win approval for a vaccine targeting a growing problem for healthcare systems. At a time when most healthcare-associated infections are in decline, C. diff is at historic highs. The Centers for Disease Control and Prevention (CDC) estimates the bacteria causes diarrhea linked to the deaths of 14,000 Americans each year. These cases place a burden on acute-care facilities--a 2012 study estimated the cost at almost $5 billion a year--that Sanofi aims to lessen with its vaccine. The vaccine stimulates an immune response intended to stop C. diff causing an infection.

Valneva--the European biotech formed by the merger of Vivalis and Intercell--also has a vaccine for C. diff in development, but is yet to present Phase Ib data. Others, including Cubist, Novartis ($NVS) and Pfizer ($PFE), are developing antibiotics targeting C. diff. In November 2012, Morningstar analyst David Krempa estimated the market for C. diff medicines and vaccines could swell to $2 billion a year, 10 times its current size. Success in Phase III would position Sanofi to capture a share of this growing market.

Another of Sanofi's late-phase vaccine candidates could generate higher sales than the C. diff shot, but also carries a much greater risk. Exane BNP Paribas analyst Vincent Meunier projects the dengue fever vaccine Sanofi is developing could bring in sales of $2.6 billion a year. Sanofi has committed a lot of resources to developing the vaccine, and would take a financial hit if trial results disappoint. Helvea analyst Odile Rundquist estimates Sanofi has invested $800 million in its dengue fever vaccine production plant and trials, Bloomberg reports. If Sanofi falters, Merck ($MRK) and Takeda Pharmaceutical could leap ahead in the race to bring a dengue fever jab to market.

- here's the C. diff release
- read Bloomberg's dengue report
- check out FierceBiotech's take

Related Articles:
Sanofi starts up dengue vaccine plant to maintain edge over Takeda
Sanofi launches PhII study of C. diff vaccine