CLINICAL TRIALS PROFILE FOR FOSCARNET SODIUM

All Clinical Trials for FOSCARNET SODIUM

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000665 ↗	Studies of the Ocular Complications of AIDS (SOCA) CMV Retinitis Trial: Foscarnet-Ganciclovir Component	Completed	Johns Hopkins University	N/A	1969-12-31	To evaluate the relative effectiveness and safety of foscarnet versus ganciclovir for the treatment of cytomegalovirus (CMV) retinitis in people with AIDS; to evaluate the relative effect on survival of the use of these two anti-CMV agents in the treatment of CMV retinitis; to compare the relative benefits of immediate treatment with foscarnet or ganciclovir versus deferral of treatment for CMV retinitis limited to less than 25 percent of zones 2 and 3. CMV retinitis is a common opportunistic infection in patients with AIDS. Ganciclovir is currently the only drug approved for treatment of CMV retinitis in immunocompromised patients. Ganciclovir suppresses CMV infections, and relapse occurs in virtually all AIDS patients when ganciclovir is discontinued. Because of their similar hematologic (blood) toxicities, the simultaneous use of ganciclovir and zidovudine (AZT) is not recommended. More recently the drug foscarnet has become available for investigational use. Studies so far indicate that remission of CMV retinitis occurs in 36 to 77 percent of patients, and that relapse occurs in virtually all patients when the drug is discontinued. The relative effectiveness of foscarnet compared with ganciclovir for the immediate control of CMV infections is unknown. Further, the long-term effects of foscarnet or ganciclovir on CMV retinitis, survival, and morbidity are unknown. There is also no definitive information on the relative effectiveness and safety of deferred versus immediate treatment for CMV retinitis confined to zones 2 and 3.
NCT00000665 ↗	Studies of the Ocular Complications of AIDS (SOCA) CMV Retinitis Trial: Foscarnet-Ganciclovir Component	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To evaluate the relative effectiveness and safety of foscarnet versus ganciclovir for the treatment of cytomegalovirus (CMV) retinitis in people with AIDS; to evaluate the relative effect on survival of the use of these two anti-CMV agents in the treatment of CMV retinitis; to compare the relative benefits of immediate treatment with foscarnet or ganciclovir versus deferral of treatment for CMV retinitis limited to less than 25 percent of zones 2 and 3. CMV retinitis is a common opportunistic infection in patients with AIDS. Ganciclovir is currently the only drug approved for treatment of CMV retinitis in immunocompromised patients. Ganciclovir suppresses CMV infections, and relapse occurs in virtually all AIDS patients when ganciclovir is discontinued. Because of their similar hematologic (blood) toxicities, the simultaneous use of ganciclovir and zidovudine (AZT) is not recommended. More recently the drug foscarnet has become available for investigational use. Studies so far indicate that remission of CMV retinitis occurs in 36 to 77 percent of patients, and that relapse occurs in virtually all patients when the drug is discontinued. The relative effectiveness of foscarnet compared with ganciclovir for the immediate control of CMV infections is unknown. Further, the long-term effects of foscarnet or ganciclovir on CMV retinitis, survival, and morbidity are unknown. There is also no definitive information on the relative effectiveness and safety of deferred versus immediate treatment for CMV retinitis confined to zones 2 and 3.
NCT00000691 ↗	A Phase II Dose-Ranging, Open-Labelled Trial of Foscarnet Salvage Therapy for AIDS Patients With Sight-Threatening CMV Retinitis Who Cannot Be Treated With Ganciclovir Due To Myelosuppression or Treatment Failure	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To examine the usefulness and safety of the antiviral drug foscarnet in treating AIDS patients with cytomegalovirus (CMV) infection that is causing sight-threatening inflammation of the retina in one or both eyes (CMV retinitis). Because of the seriousness of sight-threatening CMV retinitis in AIDS patients and a lack of other available treatments for those patients who cannot be treated with ganciclovir (DHPG) (because of its toxic effect on the body's blood-forming cells, because it did not control the disease, or because patient's blood cell or platelet counts are too low to begin with), it is worthwhile to try an immediate trial with foscarnet. AMENDED: ACTG 093 was originally designed as a randomized dose-ranging study of foscarnet maintenance therapy. Patients enrolled between March 17, 1989, and January 1, 1990, received either 60 mg/kg/day or 90/mg/kg day as maintenance therapy following the 2 week induction period. Based on the preliminary results of ACTG 015/915, which studied maintenance doses of foscarnet of 60 mg/kg/day, 90 mg/kg/day and 120 mg/kg/day, the 60-mg/kg/day and 90/mg/kg/day arms of this study have been closed. All patients entering the study beginning January 2, 1990 will receive foscarnet maintenance therapy on a 120/mg/kg/day algorithm following induction.
NCT00000697 ↗	A Study of Foscarnet in the Treatment of Cytomegalovirus (CMV) of the Eyes in Patients With AIDS Who Cannot Use Ganciclovir	Withdrawn	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To study the safety and effectiveness of foscarnet in the treatment of AIDS patients who have active infection with cytomegalovirus (CMV) that is causing inflammation of the retina (retinitis). In addition, these patients cannot be treated with ganciclovir (DHPG) because of its toxic effect on the body's blood-forming cells or because white blood cell or platelet counts were too low. CMV is a common virus, which can cause blindness and death in AIDS patients. Previous studies demonstrate that foscarnet has been effective in both AIDS and non-AIDS patients with CMV infection. Although treatment with ganciclovir (DHPG) is also effective, a significant toxicity leading to dose-limiting neutropenia (low white blood cell count) in one third of treated patients has been associated with the drug. Based on the serious nature of CMV retinitis and the lack of alternative drug therapies for DHPG-sensitive patients, the present study will evaluate the safety and efficacy of intravenous (IV) foscarnet in AIDS patients with CMV retinitis.
NCT00000726 ↗	Foscarnet Treatment of Serious CMV Retinitis Infection in Patients With Acquired Immunodeficiency Syndrome	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To explore the safety and usefulness of foscarnet, an antiviral agent, in the treatment of cytomegalovirus (CMV) retinitis. Untreated CMV retinitis is a rapidly progressive, blinding disease in AIDS patients. The manner in which foscarnet breaks down in the body and the effect of increasing periodic intravenous doses are also studied. Foscarnet is active in vitro (test tube) against herpes viruses, including CMV, by inhibiting the virus DNA polymerases, enzymes necessary for virus replication, without affecting cellular DNA polymerases. Opportunistic CMV disease in AIDS is usually seen as retinitis, colitis, esophagitis, hepatitis, pancreatitis, encephalitis, or pneumonia. Ganciclovir has been used to treat AIDS patients with CMV disease but can cause severe neutropenia (very low neutrophil cell counts). Foscarnet does not suppress the production of neutrophils or other leukocytes (myelosuppression) and has shown in vitro activity against HIV.
NCT00000729 ↗	A Multicenter Study To Determine Foscarnet Dose Response in HIV Infected Patients With PGL and/or Constitutional Disease	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine the toxicity of low dose foscarnet administered for 4 weeks to HIV infected patients who are asymptomatic, have AIDS, or other HIV associated conditions and a CD4+ lymphocyte count < 500 cells/mm3. To obtain preliminary efficacy data. Although zidovudine (AZT) has been effective in treating some AIDS patients, AZT has toxic effects in many patients and other means of treating HIV-infected persons need to be evaluated. In vitro (test tube) studies have shown that the human herpes viruses are inhibited by foscarnet and that a number of retroviruses, including HIV, are sensitive to it. It is hoped that treatment of HIV-infected individuals with foscarnet during an early phase of HIV infections will reduce the risk of developing AIDS.
NCT00000766 ↗	CMV Retinitis Retreatment Trial	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To assess the safety and efficacy of three therapeutic regimens (foscarnet, ganciclovir, or the combination) for recurrent or persistent AIDS-related cytomegalovirus (CMV) retinitis. Although therapy with foscarnet or ganciclovir halts retinitis progression in 90 percent of patients treated, relapses are common and may accelerate due to development of drug resistance, deteriorating immune function, or other factors. Treatment strategies currently being investigated include switching patients from one drug to the other or combining the two drugs.

Clinical Trial Conditions for FOSCARNET SODIUM

Condition Name

Condition Name for FOSCARNET SODIUM
Intervention	Trials
HIV Infections	21
Cytomegalovirus Retinitis	11
Herpes Simplex	4
Adult Acute Myeloid Leukemia With t(8;21)(q22;q22)	1

Condition MeSH

Condition MeSH for FOSCARNET SODIUM
Intervention	Trials
HIV Infections	21
Infections	14
Infection	14
Retinitis	11

Clinical Trial Locations for FOSCARNET SODIUM

Trials by Country

Trials by Country for FOSCARNET SODIUM
Location	Trials
United States	80
China	2
United Kingdom	1

Trials by US State

Trials by US State for FOSCARNET SODIUM
Location	Trials
California	13
New York	11
Illinois	6
Texas	5
Ohio	4

Clinical Trial Progress for FOSCARNET SODIUM

Clinical Trial Phase

Clinical Trial Phase for FOSCARNET SODIUM
Clinical Trial Phase	Trials
PHASE4	1
Phase 4	3
Phase 3	2

Clinical Trial Status

Clinical Trial Status for FOSCARNET SODIUM
Clinical Trial Phase	Trials
Completed	20
Unknown status	2
Withdrawn	2

Clinical Trial Sponsors for FOSCARNET SODIUM

Sponsor Name

Sponsor Name for FOSCARNET SODIUM
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	12
Astra USA	10
Hoffmann-La Roche	1

Sponsor Type

Sponsor Type for FOSCARNET SODIUM
Sponsor	Trials
Other	16
Industry	13
NIH	13

Foscarnet Sodium Clinical Trials Update, Market Analysis, and Exclusivity Outlook (2024-2026)
Foscarnet sodium (foscarnet disodium), an IV antiviral used mainly for cytomegalovirus (CMV) infections in immunocompromised patients, has limited late-stage development activity and a constrained commercial footprint tied to specialty hospital use, resistance patterns, and the availability of alternative antivirals. Near-term market growth is modest and largely driven by CMV treatment needs where ganciclovir/valganciclovir resistance or intolerance pushes use toward foscarnet, plus geographic variability in formularies and clinical guidelines.

H1: Foscarnet Sodium Clinical Trials Update, Market Analysis, and Projection

What clinical trials are ongoing or recently completed for foscarnet sodium?

Answer: Public registries show no broad, late-stage (Phase 3) foscarnet-sodium program in the last 3 years; activity is primarily historical/observational, pharmacovigilance, or early-cycle studies using foscarnet-containing regimens.

Foscarnet sodium is an established antiviral with long use in CMV disease, HIV-related CMV retinitis, and acyclovir-resistant HSV and VZV in select contexts. Most contemporary literature centers on clinical use outcomes, nephrotoxicity management, dosing adjustments in renal impairment, and comparative retrospective experience rather than new registration-directed Phase 3 trials.

Are there new Phase 2 or Phase 3 trials for foscarnet sodium in CMV?

Answer: No widely indexed, regulator-facing Phase 2/Phase 3 registration trial for standalone foscarnet sodium is evident in recent public updates.

Clinical trial registries and secondary trial databases typically show foscarnet sodium as:

• an investigator-chosen comparator or background standard-of-care in CMV management studies
• a repurposed or rescue agent in specific resistant populations
• a subject of regimen optimization studies (dosing, infusion strategy, electrolyte support)

What patient populations are studied in current foscarnet-sodium trials?

Common categories in recent publications and registry entries:

Last updated: July 28, 2026

• immunocompromised patients with CMV infections refractory to ganciclovir/valganciclovir
• CMV retinitis and severe CMV disease where nephrotoxicity is managed through monitoring protocols
• HSV/VZV resistant infections where foscarnet is used as alternative antiviral therapy

What outcomes are being tracked in newer clinical work?

Typical endpoints:

• virologic suppression (CMV DNA clearance kinetics, HSV/VZV lesion response)
• renal safety (serum creatinine slope, electrolyte disturbances including hypocalcemia, hypomagnesemia, hypokalemia)
• treatment continuity and dose interruptions
• time to progression or relapse in resistant disease

Trial execution constraints that limit new registration trials

Foscarnet sodium’s niche use and established role as salvage therapy for resistant CMV reduces the incentive for large registration programs. Conducting Phase 3 trials is also constrained by:

• small eligible populations after standard antivirals are used first
• provider practices that change with resistance testing availability
• the need for intensive renal monitoring, which can affect enrollment and protocol consistency

How big is the foscarnet sodium market and what drives demand?

Answer: Demand is specialty and event-driven, not growth-driven. The market tracks CMV treatment incidence in immunocompromised settings plus the prevalence of ganciclovir-resistant or intolerant disease.

Primary demand drivers

• CMV resistance and intolerance: Use rises when patients fail ganciclovir/valganciclovir or develop clinically significant adverse events that limit those options.
• Transplant and immunosuppression patterns: solid-organ and hematologic transplant caseloads drive baseline CMV disease burden; outbreaks or prophylaxis strategy changes can shift resistance patterns.
• Formulary decisions and supply stability: hospital formulary access and reliable supply strongly influence usage.

Key demand constraints

• Nephrotoxicity: foscarnet sodium’s dose-limiting renal toxicity narrows use to monitored settings.
• Alternative antivirals: in many jurisdictions, ganciclovir alternatives and resistance-guided strategies reduce the addressable use of foscarnet.
• Administration logistics: IV infusions with monitoring increases cost per treated episode and limits outpatient uptake.

How should foscarnet sodium market projections be modeled through 2028-2030?

Answer: Use a scenario-based model built around CMV event incidence and resistance/intolerance rates, then apply share shifts driven by alternative antiviral access.

Recommended forecasting structure (inputs that move the P&L)

1. Addressable treated CMV episodes
   • number of immunocompromised patients who develop CMV disease
   • proportion needing salvage therapy due to resistance or intolerance
2. Therapy selection share
   • fraction choosing foscarnet vs other salvage options
   • center-level formulary effects
3. Dose and duration
   • IV regimen dosing and typical course length in real-world practice
4. Pricing and procurement
   • tender dynamics in hospitals
   • generic supply competition (where applicable)
5. Supply stability and backorders
   • affects fill rates and revenue recognition

What direction does the model imply?

• Base case: low single-digit annual growth or flat performance, driven by stable CMV disease incidence and modest shifts in resistance management.
• Downside case: substitution away from foscarnet due to broader availability of alternatives, improved prophylaxis reducing CMV incidence, and tighter renal safety protocols reducing salvage use.
• Upside case: higher utilization in resistance-heavy settings or periods of constrained alternative availability, plus conservative clinical management that retains foscarnet in salvage pathways.

Practical bottom line projection range

Given the niche positioning and typical stability of established salvage antivirals, a defensible market projection is:

• modest growth (low single digits) in volume terms, assuming supply stability
• pricing largely flat to mildly down under generic competition and tender pressure
• revenue volatility mainly from procurement swings rather than demand expansion

Where does foscarnet sodium get used: inpatient vs outpatient, and by indication?

Answer: Nearly all meaningful volume is inpatient or specialty clinic-driven. CMV is the main indication; HSV/VZV rescue is smaller.

Indication split (high-level)

• CMV retinitis and systemic CMV disease: primary use
• HSV/VZV resistant infections: secondary
• Other off-label/rare uses: smaller contribution

Channel dynamics

• Procurement through hospital pharmacies and infectious disease services
• Tight inventory control due to IV preparation logistics
• Clinical protocols that require renal monitoring and electrolyte replacement

Which companies sell foscarnet sodium and how does competition shape pricing?

Answer: Competition is typically centered on generic supply and distribution rather than brand differentiation, with pricing dominated by tendering and supply reliability.

How competition affects market economics

• Generic entry compresses acquisition cost for hospitals.
• Consolidated supply can create temporary pricing pressure or availability disruptions.
• Regulatory and manufacturing continuity determine whether contracts are awarded.

What is the regulatory status of foscarnet sodium in the US (FDA pathway and labeling basics)?

Answer: Foscarnet sodium is an established prescription antiviral; market access is governed by FDA-approved labeling, and supply is maintained through approved application pathways for the marketed dosage forms.

In the US, foscarnet sodium is generally handled as a legacy antiviral with multiple marketed strengths and label updates focused on:

• renal safety warnings
• electrolyte monitoring requirements
• administration and dosing adjustments in renal impairment

How does foscarnet sodium compare with ganciclovir/valganciclovir and other CMV antivirals?

Answer: Foscarnet is used when ganciclovir/valganciclovir are not suitable due to resistance or intolerance. It has a distinct renal toxicity profile and does not replace ganciclovir as first-line therapy in most protocols.

Decision drivers clinicians use

• resistance profile
• prior exposure to valganciclovir and hematologic toxicity history
• renal function baseline and ability to monitor electrolytes
• speed of viral load reduction needed in severe disease

Key safety, monitoring, and pharmacoeconomic factors that impact adoption

Answer: Renal toxicity management is the limiting factor, shaping dosing feasibility and length of therapy.

Clinical monitoring that changes economics

• frequent renal function checks
• electrolyte supplementation and monitoring
• inpatient stay extension when monitoring cannot be done outside hospital

Impact on market size

Even where foscarnet is clinically appropriate, providers may:

• start at adjusted doses
• stop early due to renal compromise
• switch to alternative salvage therapies if available

Key Takeaways

• Foscarnet sodium remains a niche IV antiviral driven mainly by CMV salvage demand where resistance or intolerance limits alternative antivirals.
• Current development momentum is limited, with no clear registration-grade late-stage pipeline dominating recent public updates.
• Market projections through 2028-2030 are best modeled on CMV event incidence and resistance/intolerance rates, with share shifts driven by availability of competing antivirals and formularies.
• Revenue outlook is likely stable to modestly growing, with pricing pressure from generics and revenue volatility more tied to supply and procurement than to demand expansion.

FAQs

1. Is foscarnet sodium still standard of care for CMV retinitis in 2026?
2. What dosing adjustments are typically used for foscarnet sodium in renal impairment?
3. Does foscarnet sodium have activity against ganciclovir-resistant CMV strains?
4. What monitoring protocols reduce renal adverse events during foscarnet therapy?
5. How does supply stability affect hospital purchasing and foscarnet sodium revenue?

References

1. FDA prescribing information for foscarnet sodium (US labeling; accessed via FDA drug database and SPL/label sources).
2. Clinical review and nephrotoxicity management literature for foscarnet in CMV disease (peer-reviewed publications).
3. ClinicalTrials.gov registry searches for foscarnet sodium (foscarnet/foscarnet sodium; accessed 2024-2026 query results).