Lan Gan, MJLST Staffer
For fellow feline fanatics, you may share some of my traits. I care for my cat’s health as I care for my own. Besides giving her nutritiously balanced meals, I take notes when she’s unwell and schedule annual physicals for her, just like I would for myself. I also browse online discussions posts of cats. Some make me laugh, some give me new understanding of cat behaviors, but the ones about feline infectious peritonitis are always grim.
Feline Infectious Peritonitis, or FIP, is a severe disease that typically develops in young cats when they are infected with feline enteric coronavirus (FeCV) which later mutates into FIPV and causes inflammations.[1] The mutations happen about ten percent of the time, and, until recently, have almost always been deadly.[2]
In 2018, researchers at the School of Veterinary Medicine at UC Davis partnered with Gilead Sciences and published an article about the discovery of GS-441524, which, through their experiments with cats that were infected with FIPV in an in vitro process, “caused a rapid reversal of disease signs and return to normality with as little as two weeks of treatment in 10/10 cats and with no apparent toxicity.”[3] Another paper, published in 2019, also by researchers of the two institutions, revealed that GS-441524 was an effective treatment for cats with naturally occurring FIP.[4]
This gave cat rescuers and cat owners hope. But despite promising experiment results, Niels Pederson, who partook in the studies and was a long-time researcher devoted to FIP, warned that the development was “proof-of-concept,” showing possibility in terms of science but not immediately translating into commercially available products.[5] Subsequently, GS-441524 did not move forward to become an FDA-approved drug to treat cats.[6] Instead, it seemed to be set aside as Gilead prioritized another drug, remdesivir, which is identical to GS-441524 in part of its structural formula and has the same mechanism of inhibiting coronavirus.[7] When Gilead failed to obtain FDA approval to use remdesivir to treat Ebola, they changed course to study its effects on the then-rising Covid-19 pandemic.[8] GS-441524, with its studies on animals halted, was also part of the race and was argued by some scientists to have more efficacy in treating Covid-19 than remdesivir.[9]
The much-needed cure became inaccessible. In as early as 2019, anxious people were turning to the black market for help. GS-441524 that circulated on the black market had murky origins: potential leaks from lab orders for research, personnel that synthesized the compound themselves in overseas locations such as China.[10] The benefits of the drug, while still salient, based on surveys of cat owners who utilized them, were potentially compromised by the disparity in quality of the black market drugs, and lack of veterinary expertise involved.[11]
Pharmaceutical companies are more than incentivized to patent their research products. A search on World Intellectual Property Organization (WIPO)’s database revealed 66 patents applied for by Gilead, from as early as 2009 to as recently as July 2023.[12] The list of patents documented development in Gilead’s GS-441524 research.[13] Gilead patented GS-441524’s treatment for cats in 2018 and 2020[14], but those accounted for only 3 of the 66 patents they obtained; the rest were regarding human use.[15] Patents benefit their owners by giving them a cause of action against future infringement. They are about owning, not sharing. Patents are the culmination of a strenuous journey of scientific research. But this celebratory landmark might not go any further. Many patents do not make their way onto the market; having one is not itself an incentive for doing so.
Next comes the approval process as stipulated in federal law. 21 U.S.C. § 360b governs the approval process of new animal drugs.[16] The statute lays the burden on pharmaceutical companies – referred to as drug sponsors – of contacting the FDA after initial research of the drug, making the decision to pursue approval for the drug, and conducting tests to ensure the effectiveness and safety of the drug.[17] Additionally, the Generic Animal Drug and Patent Term Restoration Act (GADPTRA) of 1988 provides an abbreviated process for generic copies of approved new animal drugs;[18] the Minor Use and Minor Species Animal Health Act (the “Mums Act”) of 2004 paves paths for drugs affecting a small population of major species of animals (defined as horses, dogs, cats, cattle, pigs, turkeys and chickens) and minor species (those that are not major species) that have few drugs available to them.[19] In 2018, the Animal Drug and Animal Generic Drug User Fee Amendments expanded the eligibility for conditional approval of non-MUMS drugs intending to treat a serious or life-threatening disease or condition or address an unmet animal or human health need, for which a demonstration of effectiveness would require a complex or particularly difficult study or studies.[20]
How has GS-441524 escaped the statutory provisions when they have been amended to be more inclusive? There may be various reasons. It may not qualify for conditional approval under 21 U.S.C. § 360ccc(a)(1)(ii) because peer-reviewed articles have already demonstrated the drug’s effectiveness. It may be hard to quantify the FIP-affected cat population to meet the “minor use” threshold set out in the Mums Act because of the difficulty of FIP testing. Current testing cannot differentiate between FeCV and the mutated FIPV, and an FIP diagnosis is often assumed for young cats based on their higher infection rate.[21] Lastly, no matter which approval process GS-441524 is eligible to take, the process wouldn’t start unless Gilead decides to contact the FDA and set forth the drug for approval. Current statutes create paths, but no incentives to do so. The market may provide some monetary incentives, as treatment costs via the black market can be up to $10,000 for 12 weeks[22], but this is singularly held back by the decision to prioritize approval for human treatment, and the presumption that the approval process of an animal drug would negatively impact the approval process of a similar drug for humans.[23]
The black market is not a long-term solution for FIP treatment. Though the U.S. has yet to adjudicate the circulation of unlicensed FIP treatment, in July 2023, a woman in China was sentenced to 15 years in prison and fined with more than $5 million in damages for producing and selling fake, substandard products pursuant to China’s criminal law statutes.[24] Gilead also holds the exclusive patents on feline treatments. Facing unclear prospects for legitimate FIP treatment, subsequent statutory amendments need to create actual incentives to spur innovation in animal drugs, in addition to the creation of paths. The law should also create safeguards to promote transparency and fairness in the application review process in order to reduce bias against animal drugs.
Notes
[1] Feline Infectious Peritonitis, Cornell Feline Health Center, https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-infectious-peritonitis (last visited Oct. 2, 2023).
[2] Id.
[3] B.G. Murphy et al., The Nucleoside Analog GS-441524 Strongly Inhibits Feline Infectious Peritonitis (FIP) Virus in Tissue Culture and Experimental Cat Infection Studies, 219 Veterinary Microbology 226, 226 (2018).
[4] Niels C Pedersen, Efficacy and Safety of the Nucleoside Analog GS-441524 for Treatment of cats with Naturally Occurring Feline Infectious Peritonitis, 21(4) J. of Feline Med. & Surgery 271, 271 (2019).
[5] Human Antiviral ‘GS-441524’ Shows Great Promise Against Infectious Disease in Cats, Science Daily (Feb. 13, 2019), https://www.sciencedaily.com/releases/2019/02/190213100442.htm.
[6] Sarah Zhang, A Much-Hyped COVID-19 Drug Is Almost Identical to a Black-Market Cat Cure, The Atlantic (May 8, 2020), https://www.theatlantic.com/science/archive/2020/05/remdesivir-cats/611341/.
[7] Id.
[8] Kai Kupferschmidt & Jon Cohen, WHO Launches Global Megatrial of the Four Most Promising Coronavirus Treatments, Science (Mar. 22, 2020), https://www.science.org/content/article/who-launches-global-megatrial-four-most-promising-coronavirus-treatments.
[9] E.g., Victoria C. Yan & Florian L. Muller, Advantages of the Parent Nucleoside GS-441524 over Remdesivir for Covid-19 Treatment, 11 ACS Med. Chemistry Letters 1361, 1361 (2020).
[10] See Sarah Zhang, A Much-Hyped COVID-19 Drug Is Almost Identical to a Black-Market Cat Cure, The Atlantic (May 8, 2020), https://www.theatlantic.com/science/archive/2020/05/remdesivir-cats/611341/; see also Sarah Jones et al., Unlicensed GS-441524-Like Antiviral Therapy Can Be Effective for at-Home Treatment of Feline Infectious Peritonitis, 11 Animals 2257, 2258 (2021).
[11] Sarah Jones et al., Unlicensed GS-441524-Like Antiviral Therapy Can Be Effective for at-Home Treatment of Feline Infectious Peritonitis, 11 Animals 2257, 2264–67 (2021).
[12] CHEM:(BRDWIEOJOWJCLU-LTGWCKQJSA-N), WIPO, https://patentscope.wipo.int/search/en/result.jsf?_vid=P22-LN8EIR-06824 (last visited Oct. 2, 2023).
[13] Id.
[14] See World Patent No. 169,946 (filed Mar. 13, 2018); see also U.S. Patent No. 0,296,584 (filed Mar. 13, 2018); see also U.S. Patent No. 0,376,014 (filed Apr. 17, 2020).
[15] See CHEM:(BRDWIEOJOWJCLU-LTGWCKQJSA-N), WIPO, https://patentscope.wipo.int/search/en/result.jsf?_vid=P22-LN8EIR-06824 (last visited Oct. 2, 2023).
[16] 21 U.S.C. § 360b.
[17] From an Idea to the Marketplace: The Journey of an Animal Drug through the Approval Process, FDA (Aug. 14, 2020), https://www.fda.gov/animal-veterinary/animal-health-literacy/idea-marketplace-journey-animal-drug-through-approval-process.
[18] Generic Animal Drug and Patent Term Restoration Act (GADPTRA), FDA (Apr. 24, 2023), https://www.fda.gov/animal-veterinary/guidance-regulations/generic-animal-drug-and-patent-term-restoration-act-gadptra.
[19] Conditional Approval Explained: A Resource for Veterinarians, FDA (Sept. 17, 2020), https://www.fda.gov/animal-veterinary/resources-you/conditional-approval-explained-resource-veterinarians.
[20] 21 U.S.C. § 360ccc (a)(1)(ii).
[21] Feline Infectious Peritonitis, Cornell Feline Health Center, https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-infectious-peritonitis (last visited Oct. 2, 2023).
[22] Sarah Jones et al., Unlicensed GS-441524-Like Antiviral Therapy Can Be Effective for at-Home Treatment of Feline Infectious Peritonitis, 11 Animals 2257, 2264–67 (2021).
[23] Id.
[24] Wu Shubin (吴淑斌), Zhishou Maoyao Yishen Huoxing 15 Nian: Maoquan “Jiumingyao” de Yinmi Shengyi (制售猫药一审获刑15年:猫圈“救命药” 的隐秘生意) [Sentenced at Trial for 15 Years for Manufacturing and Selling Medicine for Cats: The Secret Business of Life-Saving Drugs in Cat-loving Communities], Sanlian Shenghuo Zhoukan (三联生活周刊) [Sanlian Lifeweek] (July 20, 2023), https://mp.weixin.qq.com/s/VKJO_AIVBy3Hm6GhWUOnWA.
