The study followed 14 cats with progressive FeLV infection and associated disease, without a comparison group. Reported median survival from the start of raltegravir was 10.8 months, but whether raltegravir prolonged these cats’ lives is unknown. The amount of viral DNA integrated into cells fluctuated without a consistent pattern during administration and follow-up. The cats also received supportive care, so their clinical course cannot be attributed to raltegravir, and the findings do not establish that it eliminated the virus or produced a cure.
This was a prospective, longitudinal, single-arm intervention involving 14 naturally infected cats with progressive FeLV infection and FeLV-related disease. All met progressive-infection criteria at enrolment, although some may not have had progressive infection at their initial diagnosis. The day-45 paired viral RNA analysis included 12 cats; the day-90 analyses included four cats in one dose group and seven in another. Nine cats were re-evaluated at day 180. Laboratory assay controls do not constitute a clinical comparison group.
Proviral DNA loads showed heterogeneous fluctuations without a consistent raltegravir-associated trend during administration or follow-up. These findings do not establish elimination of integrated virus or reversal of progressive infection. Reported median survival from raltegravir initiation was 10.8 months, with a reported 95% confidence interval of 8.9–N/A; the upper limit is listed as N/A. This estimate describes survival in the cohort but does not demonstrate a survival benefit attributable to raltegravir.
The observations constitute level C evidence. The authors state that the absence of a control group and concurrent supportive therapies prevent causal attribution of clinical evolution to raltegravir. Observed stability or improvement therefore cannot be separated from the effects of supportive care or other influences. The small sample, considerable inter-individual variability and possible overestimation of survival calculated from the first positive FeLV test further limit interpretation. Not all cats completed scheduled assessments because of deterioration, death, financial constraints or compliance limitations.
Longer-duration effects and effects in cats with clinically stable or asymptomatic progressive infection could not be assessed. Anti-FeLV antibody responses were not evaluated either. Internal inconsistencies and corrupted text in the supplied source further constrain interpretation. The design provides direct descriptive clinical observations in cats but cannot establish antiviral efficacy, improved survival or cure. Whether raltegravir improves survival in cats with progressive FeLV infection remains unresolved; the authors indicate that this question requires longer-term evaluation.
In this uncontrolled cohort of 14 cats with progressive FeLV infection and associated disease, proviral DNA loads fluctuated without a consistent raltegravir-associated trend. Reported median survival from raltegravir initiation was 10.8 months, with a 95% confidence interval of 8.9–N/A. These are level C observations, limited by the small sample, concurrent supportive care, variability between cats, incomplete assessments and problems in the source.
Whether raltegravir improves survival remains unresolved. This study cannot causally attribute the clinical course to raltegravir or establish antiviral efficacy, elimination of integrated virus, reversal of progressive infection or cure. Longer-duration effects, effects in cats with clinically stable or asymptomatic progressive infection, and anti-FeLV antibody responses were not assessed. Survival calculated from the first positive test may have been overestimated.
Excerpt verified in the source — verbatim, in the source's own language“From treatment initiation, MST-t0 was 10.8 months (324 days; 95% CI 8.9–N/A).”
This describes survival in the enrolled cohort. The upper confidence limit is reported as N/A, and the absence of a comparator prevents interpretation as a survival benefit caused by raltegravir.
Excerpt verified in the source — verbatim, in the source's own language“However, in the absence of a control group and given the concurrent use of supportive therapies, no causal relationship between raltegravir treatment and clinical evolution can be inferred.”
Observed stability or improvement cannot be separated from supportive care or other influences using this design.
Excerpt verified in the source — verbatim, in the source's own language“This was a prospective, longitudinal, single-arm interventional study (January 2022–September 2025) assessing clinical and virological responses to raltegravir in 14 naturally infected, progressively FeLV-positive cats with FeLV-related disease.”
This establishes the clinical population and uncontrolled design. Laboratory assay controls do not constitute a clinical comparison group.
Excerpt verified in the source — verbatim, in the source's own language“Across the treatment and follow-up period, proviral DNA load showed heterogeneous fluctuations with no consistent treatment-associated trend ( Figure 2 ).”
The measured proviral burden did not show a consistent response. This does not establish elimination of integrated virus or reversal of progressive infection.
The authors explicitly describe the survival effect as uncertain and requiring longer-term evaluation. The reported survival estimates do not resolve that question.
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