The 1st and only approved treatment of CKD anaemia in cats
Varenzin™ is an innovative, easy to use oral suspension for the treatment of non-regenerative anaemia associated with chronic kidney disease (CKD) in cats.
First-in-class treatment stimulating endogenous erythropoietin (EPO) production
Varenzin’s oral formulation contains fish oil, known to be highly appealing to cats, with 88% voluntary acceptance1,7
Convenient at-home treatment with a low dosing volume.
Why is it important to treat anaemia in CKD cats?
Up to 65% of cats with CKD develop non-regenerative anaemia as their renal disease worsens.3
CKD anaemia is caused by several factors, primarily a reduction of erythropoietin (EPO), a hormone released from the kidney that signals bone marrow to make red blood cells.3
Anaemia associated with CKD significantly impacts a cat’s quality of life3 and is associated with reduced survival4 , yet it is often overlooked, due to limited options for therapy.
How Varenzin works?
Leveraging Nobel Prize-winning science, Varenzin (Molidustat) advances the science of feline CKD anaemia treatment.9,5 Varenzin is an innovative oral medication containing Molidustat, that helps cats make more red blood cells.
CKD anaemia is primarily caused by decreased production of EPO (erythropoietin), the hormone signalling bone marrow to make red blood cells. The enzyme HIF-PH is normally responsible for maintaining this balance, but is dysregulated in cats with CKD, resulting in reduced levels of EPO.3
Varenzin (Molidustat) blocks this enzyme, enabling cats to produce their own EPO again.9, 10
More EPO leads to more red blood cells and better oxygen delivery throughout the body
Advancing the science of feline CKD anaemia treatment
In the past, treatment of CKD associated anaemia meant reaching for off-label human products, making management of CKD anaemia challenging. Varenzin provides an easy to administer, convenient at home treatment, specifically designed to stimulate a cat's own red blood cell production.9
Erythropoietin analogues (e.g. darbepoetin) | Varenzin™ |
❌ Licensed for human use | ✅ Designed specially for cats |
❌ Doesn't stimulate a cat's own EPO production | ✅ Helps cats to produce their own EPO |
❌ Requires regular injections in clinic | ✅ Daily oral suspension, for convenient at home treatment |
Treating anaemia earlier with Varenzin™
70% of vets would start treatment with Varenzin as soon as blood results indicate anaemia even if there are no obvious clinical signs.2
Earlier intervention in cats with CKD anaemia may help preserve renal function8. In stage 2 CKD, every 1% increase in HCT is associated with a 10% decrease in the risk of CKD progression.6
Varenzin empowers you to effectively manage feline CKD anaemia8,9
Increases HCT within 4 weeks after starting treatment.8
5.3% increase in HCT shown in cats on Varenzin after 1 month of treatment vs placebo group8†
After 1 month on Varenzin, 68% of cats achieved treatment success vs 17% in the control group (p<0.001)8§
Varenzin has proven long-term tolerability in real-world studies8¶.
In the pivotal field study, there was no evidence of adverse effects attributed to Varenzin when given alone or in combination with other medications.8
Varenzin, enhancing care for cats with CKD anaemia.
Varenzin is the simple and convenient solution for the treatment of feline CKD anaemia designed for at home use9.
The management of Feline CKD can be challenging and require multiple therapies - discover Elanco's solutions to support the management of this complex disease in your practice.
* Referenceable claims in digital & social copy can be found on this page. Full reference list below.
1. Elanco study ID 204976
2. Varenzin™ Market research with 202 Veterinarians in USA and Germany (2019)
3. Chalhoub S, et al. Anemia of renal disease: what it is, what to do and what’s new. J Feline Med Surg. 2011;13(9):629-40
5. Moslehi J et al. J Clin Invest 2019;130:4-6
6. Chakrabarti S, Syme HM, Elliott J. Clinicopathological Variables Predicting Progression of Azotemia in Cats with Chronic Kidney Disease. Journal of Veterinary Internal Medicine. John Wiley & Sons, Inc.; 2012. p. 275–81.
7. Pekel et al. Journal of Applied Animal Research (2020), 48:1, 281-292
8. Schmidt F et al. J Vet Int Med 2026;40
9. Varenzin Summary of Product Characteristics 2025
10. IRIS New Therapeutic Approaches to Management of Anemia and Iron. 2025. Available from https://www.iris-kidney.com/treatment-of-anemia-in-cats-with-ckd. Accessed March 2026
†Mean HCT of Varenzin treated group was 22.5% on day zero and 27.8% on day 28, whereas mean HCT of control group was 22.6% on day zero and 22.4% on day 28
§ Success defined as a 4% increase in mean HCT vs baseline
¶ Based on Varenzin use in cats with CKD over a 6month period
