Sanofi recently canned the development of its Clostridium difficile vaccine, dashing its hopes of winning a license for the first shot against the bacterium that's often found in healthcare facilities. But the drugmaker's loss is a win for Pfizer and Valneva, which boast their own late-stage candidates aiming for a share of a market potentially worth $1 billion.
Fast-tracked by the U.S. FDA in August 2014, Pfizer’s PF-06425090 is now first in line, according to market research firm GlobalData. The recombinant vaccine is designed to induce antibody responses against two main toxins—A and B—produced by C. diff. After positive interim data from the phase 2 trial, Pfizer initiated a phase 3 study in March 2017 in approximately 16,000 participants. It will read out in September 2020.
The CDC estimated that the U.S. experienced about half a million cases in 2011, and 29,000 people—mostly older adults—died within 30 days of diagnosis. Growing C. diff infections at healthcare facilities and antibiotic resistance are “driving a high need for prophylactic options to reduce the risk of infection in vulnerable patients,” GlobalData healthcare expert Thomas Moore observed in a recent analysis.
If Pfizer’s candidate delivers in the phase 3 efficacy study, “GlobalData expects strong uptake for this product, driven by Pfizer’s previous experience manufacturing and distributing vaccines,” Moore said. As industry watchers know, the company already markets the world's best-selling vaccine, Prevnar 13, to protect against pneumococcal disease.
Before the phase 3 flop at Sanofi, Credit Suisse analysts previously estimated sales of Sanofi’s C. diff vaccine hopeful could reach $525 million, while predicting Pfizer’s could reach $450 million.
But PF-06425090 isn’t the only candidate in advanced clinical testing. French firm Valneva’s VLA84 already passed a phase 2 study last year, and as GlobalData analysts see it, the vaccine’s contrasting method of action “could give it an advantage when it comes to successfully meeting phase 3 trial endpoints.” But the cost of late-stage testing has been a barrier for the biotech, and it had to put the vaccine on hold for now. It plans to one day conduct a head-to-head, noninferiority test against the first approved C. diff vaccine.
“The size and experience of Valneva make it unlikely that the company could effectively market this product on its own, making its success heavily reliant on securing a licensing deal with big pharma,” GlobalData's Moore said of the company's development and marketing path.
Valneva has made some commercialization moves in recent years toward independence. It recently took control of marketing of its Japanese encephalitis vaccine Ixiaro back from GlaxoSmithKline. Approved in about 35 countries and sold under the name Jespect by Seqirus in Australia and New Zealand, the vaccine returned about €53 million ($64 million) in 2016; the U.S. military was its biggest customer. The biotech also built a Canadian subsidiary early 2015 to market cholera vaccine Dukoral there. Sales for that vaccine were €24.6 million in 2016.
The company boasts on its website that more than 68% of its product sales are now generated by its own marketing network. But if Valneva were to compete in a C. diff market that could be worth $1 billion, it'd likely face formidable competition from a leading vaccine maker.
Plus, GlobalData analysts said key opinion leaders “did not envision a blanket vaccination program for all patients above a certain age.” With that, Moore said identifying appropriate patient groups to receive vaccination could make a big difference for the future of Pfizer’s and Valneva’s products.