Chlamydia Treatment: Is it the End of the Antibiotic Era?

Chlamydia is the most common bacterial sexually transmitted infection across the world. Chlamydia infection is asymptomatic in 50-88% of men and women, and 46% of infections resolve spontaneously after a year. In women, persistent chlamydia infection can cause pelvic inflammatory disease, ectopic pregnancy, tubal infertility, and in men, epididymitis and epididymo-orchitis. Chlamydia infection can strike at any age, although it is most frequent in those under the age of 25, with rates of diagnosis increasing in women aged 16 to 19 and men aged 20 to 24.

Azithromycin has been considered the first-line treatment for chlamydia infection for many years. Recent research, however, suggests the emergence of azithromycin resistance due to its widespread use to treat infections. For chlamydia treatment, data from observational studies comparing azithromycin to doxycycline revealed that azithromycin had a greater chlamydia treatment failure rate than doxycycline. To combat resistance development, the CDC recently updated STI recommendations for managing chlamydia in 2021. According to these revised guidelines, the recommended therapy for chlamydia treatment is now doxycycline 100 mg twice daily orally for 7 days.

The development of antibiotic resistance and the rise in infected cases have become a global threat. Over the past 10 years, the diagnosed cases of chlamydia infection have peaked due to more sensitive tests and increased chlamydia testing. As per DelveInsight’s Chlamydia Epidemiology Report, seven major markets accounted for more than 3 million cases in 2021, and it is estimated that the cases will reach up to 5 million by 2032. The United States contributed the highest cases among the seven major markets, while Italy accounted for the lowest in 2021. 

How to Circumvent the Challenges?

Antimicrobial stewardship is a program that promotes the right use of antimicrobials in order to avoid resistance, which is one of the most serious public health issues in the United States. The revised updates were recommended because of concerns about higher rates of azithromycin and ceftriaxone resistance when taken at lower doses.

Besides doxycycline  100 mg twice daily for 7 days, other substitute regimens, either azithromycin 1 g orally in a single dose or levofloxacin 500 mg once daily for 7 days, are also recommended to subdue the development of antibiotic resistance. Notably, a delayed-release (DR) formulation of doxycycline is available on the market to reduce pill burden and alleviate gastrointestinal symptoms. Doxycycline 200 mg DR tablets should be used once a day for 7 days as part of this regimen. This formulation is as effective as the instant release formulation but is more expensive. Furthermore, Ofloxacin (but not all other quinolones) is also effective in chlamydia treatment. In general, erythromycin is regarded as a backup chlamydia medicine for those who are unable to follow another regimen.

Furthermore, chlamydia screening is implemented in several countries and regions, including the US and the UK, to reduce the risks. Chlamydia screening is advised for all women under the age of 25, pregnant women, and those at high risk of infection.

Potential Chlamydia Treatment Options in Development

Chlamydia is one of the major bacterial pathogens that infect humans. Antibiotics are the only currently available chlamydia treatment option. However, there is mounting pressure to develop chlamydia vaccines with high reinfection rates. One of the most challenging aspects of chlamydia vaccine trials research is replicating mouse vaccine trial results in other host species, specifically nonhuman primates. Over the last 30 years, limited attempts have been to replicate mouse model chlamydia vaccine trials results in nonhuman primates.

Many key assets, including chlamydia vaccines, are at the preclinical stage of development. The major chlamydia companies such as Evofem Biosciences, QureTechBio, Vault Pharma, Aeterna Zentaris, Melinta Therapeutics, Abera Bioscience, Prokarium, Blue willow Biologics, Microbiotix, Abivax, and others are currently working to develop new drugs for chlamydia treatment which can be available in the chlamydia market in the upcoming years.

In addition, Evofem Biosciences’ EVO100 is a preventive vaginal gel that is in the late phase of development to prevent urogenital chlamydia and gonorrhea in women. The drug is intended to diminish certain vaginal infections by

• Maintaining healthy vaginal flora and establishing an environment that is unfavorable to the growth and proliferation of harmful bacteria by balancing vaginal pH.
• Using a novel mechanism of action that could aid in addressing drug resistance concerns

The US Food and Drug Administration has granted Evofem Fast Track Designation to prevent chlamydia in women. According to the Phase IIb AMPREVENCE study findings, which evaluated EVO100 for the prevention of chlamydia and gonorrhea, the medicine met its primary and secondary goals and was generally safe and well-tolerated. The chlamydia medication is presently being tested in pivotal Phase III trials in women for urogenital chlamydia trachomatis and Neisseria gonorrhea infection. Top-line results are projected in 2022, with a launch date in the United States in 2023.

Moreover, as per DelveInsight analysis, the total chlamydia market size was found to be over USD 50 million in 2021 and is expected to increase and reach up to USD 700 million by 2032. The rising cases of chlamydia infections present an opportunity for companies to develop therapies to prevent the disease and improve the chlamydia treatment landscape. Consequently, the focus on research and development of novel chlamydia treatments is expected to engender market growth in the coming years.

Expected Roadblocks

Chlamydia is by far the most common sexually transmitted infection, with a high incidence rate that is predicted to climb further in the future, needing chlamydia treatment. A considerable proportion of asymptomatic infections go undiscovered, and as a result, the chlamydia treatment market might be much bigger than expected. Furthermore, the chlamydia treatment guidelines and screening recommendations have been modified. In addition, with the emergence of incredibly sensitive and specific cost-effective testing techniques, diagnosis has become rapid and simple, driving the chlamydia treatment market even further.

Moreover, a slew of chlamydia medicines are in the early phases of research, including chlamydia infection blockers (CIBs), VPI-201, ABX196, and others, paving the way for the future chlamydia treatment market. Several other companies are also striving to provide novel chlamydia products.

On the other hand, Doxycycline therapy is bothersome since people with GERD must sit upright for 30 minutes after each dosage. Questions have been expressed concerning azithromycin's effectiveness for concurrent rectal C. trachomatis infection, which can occur in women and cannot be predicted by reported sexual activity. Both of these limitations are constraining chlamydia treatment market expansion. Furthermore, the range of chlamydia screening procedures makes it difficult for physicians and researchers to decide which are effective, which has an impact on the growth of the chlamydia treatment market. In addition, there has been a dearth of studies relating chlamydial species to their ultimate host. As a result, the chlamydia treatment market is seeing slow development. Furthermore, there is no consensus on the most efficient strategy for increasing chlamydia screening, which is another factor influencing the chlamydia treatment market.

Furthermore, antibiotic misuse, along with patient chlamydia drug abuse, has led to an increase in antimicrobial-resistant (AMR) strains of Chlamydia trachomatis, limiting the growth of the chlamydia treatment market. Furthermore, noncompliance with recommended treatments, as well as a lack of information about chlamydia among patients and healthcare professionals, are among the important factors influencing the chlamydia treatment market growth.

Way Ahead

The variety of ophthalmic, vaginal, and respiratory infections caused by Gram-negative bacteria of the genus chlamydia provide a persistent global burden and significant public health concern. Conjunctivitis and blinding trachoma are the most common diseases, followed by non-gonococcal urethritis, cervicitis, pelvic inflammatory disease, ectopic pregnancy, tubal factor infertility, and interstitial pneumonia. Failures in chlamydia screening and other preventive initiatives have led to the current medical consensus that an effective prophylactic vaccination is the best way to protect humans from chlamydial infections. Despite proven animal vaccinations, there is no human chlamydia vaccine. The proper delivery of vaccine antigens to produce safe and effective immune effectors to bestow long-term protective immunity has been a major issue. The advent of biodegradable polymeric nanoparticles and adjuvanted derivatives may hasten the realization of the human vaccination dream in the near future.

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