Infectious Disease Regulatory Watch: June Highlights

This is our monthly column looking at federal regulatory topics including recent decisions, personnel changes, and news related to the agencies and infectious disease.

In recent weeks there has been a flurry of activity on the regulatory front including many FDA approvals of treatments related to infectious disease and an expanded vaccine indication. Here is a listing of those approvals as well a the news reports and phase 3 study data that supported their approvals.

Bulevirtide Approved as First US Treatment for Chronic Hepatitis Delta Virus

The FDA approved bulevirtide-gmod (Hepcludex; Gilead Sciences) injection on May 22, 2026, marking a historic regulatory milestone: the first approved treatment for chronic hepatitis delta virus (HDV) infection in the United States.¹ The approval covers adults without cirrhosis or with compensated cirrhosis and was granted to Gilead Sciences under the FDA's Accelerated Approval pathway, with Priority Review, Breakthrough Therapy Designation, and Orphan-Drug Designation all previously conferred on the agent.

The decision closes a longstanding therapeutic void in a disease that, despite its severity, has carried no approved pharmacologic options in the US until now.

FDA Approves Ensitrelvir as First Oral Postexposure Prevention Option for COVID-19

The US Food and Drug Administration (FDA) approved ensitrelvir (Xocova) for postexposure prophylaxis (PEP) in adults and children 12 years or older following contact with an individual infected with COVID-19.²

Developed by Shionogi, ensitrelvir becomes the first and only oral antiviral approved in the United States to help prevent symptomatic COVID-19 after exposure. The approval came ahead of the FDA's Prescription Drug User Fee Act target date of June 16, 2026.²

FDA Approves Tebipenem Pivoxil as First Oral Carbapenem For Complicated Urinary Tract Infections

The FDA has approved tebipenem pivoxil (Utebzi; Spero Therapeutics/GSK) for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis, making it the first oral carbapenem antibiotic available in the US for this indication. The approval offers a new treatment pathway for patients who have historically required intravenous (IV) therapy, particularly in cases involving drug-resistant pathogens.^3-5

FDA Expands Merck Pneumococcal Vaccine Indication to Include At-Risk Children and Adolescents

Merck announced the FDA has expanded the indication for the company’s Pneumococcal 21-valent Conjugate Vaccine (Capvaxive) to include children and adolescents aged 2 to 17 years who have completed a primary pneumococcal vaccination series and have underlying chronic medical conditions that increase their risk of pneumococcal disease.

Review of Cefepime and Zidebactam: A Novel Antibiotic Approved to Treat Complicated Urinary Tract Infections

On May 30 2026, the FDA approved cefepime and zidebactam (Zaynich) for the treatment of complicated urinary tract infections (cUTI) and pyelonephritis in adults caused by susceptible strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae complex, and Pseudomonas aeruginosa.^6,7

This antibiotic previously received Qualified Infectious Disease Product and Fast Track designations from the FDA.⁶ It combines the fourth generation cephalosporin, cefepime, with zidebactam, a beta-lactamase inhibitor and non-beta-lactam.⁷ Cefepime targets penicillin-binding protein-3(PBP3) in gram-negative organisms, and zidebactam selectively inhibits penicillin-binding protein-2(PBP2).⁷

Check back next month for more news and commentary around the federal government’s actions related to infectious disease.

References

1. US Food and Drug Administration. FDA approves first treatment for chronic hepatitis delta virus (HDV) infection. Published May 22, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-chronic-hepatitis-delta-virus-hdv-infection

2. Shionogi announces FDA approval of XOCOVA (ensitrelvir), the first and only oral option to help prevent COVID-19 following exposure. News release. Shionogi & Co Ltd. June 1, 2026. Accessed June 1, 2026.
https://www.businesswire.com/news/home/20260531335709/en/Shionogi-Announces-FDA-Approval-of-XOCOVA-ensitrelvir-the-First-and-Only-Oral-Option-to-Help-Prevent-COVID-19-Following-Exposure

3.Utebzi (tebipenem pivoxil) approved in the US for adults with complicated urinary tract infections (cUTIs). GSK. News release. June 17, 2026. Accessed June 17, 2026. https://www.gsk.com/en-gb/media/press-releases/utebzi-tebipenem-pivoxil-approved-in-the-us-for-adults-with-complicated-urinary-tract-infections-cutis/

4.Spero Therapeutics Announces First Quarter 2026 Operating Results and Provides Business Update. Spero Therapeutics. News release. Published May 13, 2026. Accessed June 18, 2026. https://www.globenewswire.com/news-release/2025/12/19/3208446/0/en/Spero-Announces-NDA-Resubmission-of-Tebipenem-HBr-by-GSK-to-the-FDA-for-the-Treatment-of-Complicated-Urinary-Tract-Infections-Including-Pyelonephritis.html

5.PIVOT-PO Phase 3 Data Show Tebipenem HBr's Potential as the First Oral Carbapenem Antibiotic for Patients with Complicated Urinary Tract Infections (cUTIs). Spero Therapeutics. News release. Published October 21, 2025. Accessed June 18, 2026. https://s3.amazonaws.com/b2icontent.irpass.cc/2748/rl158673.pdf

6.Wockhardt Limited. Wockhardt Receives U.S. FDA Approval for ZAYNICH^TM (cefepime and zidebactam), a Novel Intravenous Antibiotic for the Treatment of Adult Patients with Complicated Urinary Tract Infection including Pyelonephritis. Published May 30, 2026. Accessed June 17, 2026. https://www.wockhardt.com/wp-content/uploads/2026/05/wockhardt-zaynich-fda-approval-press-release.pdf

7. ZAYNICH [Prescribing Information]. Newark, DE. Wockhardt Suisse USA LLC. May 2026.