Ridinilazole (previously known as SMT19969) is an investigational

small molecule In molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are small molecules; ...

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

under evaluation for

oral administration Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

for the treatment of ''Clostridioides difficile'' infection (CDI).

In vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

, it demonstrates

bactericidal A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their p ...

activity against ''C. difficile'' and suppresses

bacterial toxin Microbial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. ...

production; the

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...

is thought to involve inhibition of cell division. It possesses desirable properties for the treatment of CDI, namely that it is a

narrow-spectrum antibiotic A narrow-spectrum antibiotic is an antibiotic that is only able to kill or inhibit limited species of bacteria. Examples of narrow-spectrum antibiotics include fidaxomicin and sarecycline Sarecycline, sold under the brand name Seysara, is a ...

which exhibits activity against ''C. difficile'' while having little impact on other normal

intestinal flora Gut microbiota, gut microbiome, or gut flora are the microorganisms, including bacteria, archaea, fungi, and viruses, that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the g ...

and that it is only minimally absorbed systemically after oral administration. When Ridinilazole was originally developed, there were only three antibiotics in use for treating CDI:

vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat certain bacterial infections. It is administered intravenously ( injection into a vein) to treat complicated skin infections, bloodstream infections, endocarditis, bone an ...

fidaxomicin Fidaxomicin, sold under the brand name Dificid (by Merck) among others, is the first member of a class of narrow spectrum macrocyclic antibiotic drugs called tiacumicins. It is a fermentation product obtained from the actinomycete '' Dactylosp ...

, and

metronidazole Metronidazole, sold under the brand name Flagyl and Metrogyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vagino ...

. The recurrence rate of CDI is high, which has spurred research into other treatment options with the aimed reduce the rate of recurrence. , two

phase II trials The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases ...

had been completed and two phase III trials comparing ridinilazole with vancomycin for CDI were anticipated to conclude in September 2021. Ridinilazole was designated as a

Qualified Infectious Disease Product The Food and Drug Administration Safety and Innovation Act of 2012 (FDASIA) is a piece of American regulatory legislation signed into law on July 9, 2012. It gives the United States Food and Drug Administration (FDA) the authority to collect user ...

(QIDP) and was granted

Fast Track status Fast track is a designation by the United States Food and Drug Administration (FDA) of an investigational drug for expedited review to facilitate development of drugs that treat a serious or life-threatening condition and fill an unmet medical ne ...

by the U.S. FDA. Fast Track status is reserved for drugs designed to treat diseases where there is currently a gap in the treatment, or a complete lack thereof. The QIDP designation adds five more years of exclusivity for ridinazole upon approval.

References

{{reflist Antibiotics Benzimidazoles 4-Pyridyl compounds

See also

References