IN THE PIPELINE: Drugs For Those No Longer A Puppy
Old dogs are learning new tricks - such as swallowing their medications.
With improvements in veterinary care and pet owners' seemingly unlimited capacity to spend money on their furry companions, the life span of dogs is increasing, spurring demand for new and cutting-edge medicines.
"Older pets have geriatric diseases," said Folkert Kamphuis, vice president, new products marketing and business development, for Pfizer Animal Health, a unit of Pfizer Inc. (PFE).
Sales of medications for pets reached $1.6 billion in 2001, up 30% in just three years, according to the Animal Health Institute, which represents makers of animal medicines. Those were the latest available figures.
Among the best-selling prescription treatments for dogs are Pfizer's Rimadyl for pain management, including arthritis, and Revolution to prevent parasites. Other top sellers include parasitic treatments Frontline and Heartgard from Merial , a joint venture of Merck & Co. (MRK), and Aventis S.A. (AVE). The companies don't break out sales for individual medications.
Sales of drugs for pets are a drop in the bucket compared with the more than $192.2 billion in overall pharmaceutical sales in 2002, but there is still a large potential marketplace. U.S. households own an estimated 60 million dogs, according to the American Society for the Prevention of Cruelty to Animals, and Americans spent $29.5 billion on their pets in 2002, the American Pet Products Manufacturers Association says.
As with humans, one of the leading killers of dogs is cancer. If a dog lives 10 years or more, there is a more than 50%-60% chance that it will get the disease, according to Dr. Cheryl London, assistant professor at the University of California, Davis, School of Veterinary Medicine.
Merial is in the early stages of developing a vaccine to prevent melanoma, a deadly form of skin cancer, according to Dr. Kevin Schultz, head of global research and development for the company. Merial is working with the Sloan-Kettering Institute of New York on the research, Schultz said. At this point, it is too soon to provide any timetable for its possible entry into the marketplace.
London at U-C Davis is working on a treatment for a variety of cancers. Her effort involves a small molecule inhibitor that blocks the chemical signal responsible for cancer growth.
Right now, the treatment is in the registrational study stage at the Food and Drug Administration, which approves and oversees both animal and human medications, London said. The FDA did not respond to requests for comment. Pfizer is a partner on the project, according to London, although Pfizer declined to discuss any specific drugs that are in development.
London also notes that there is a growing focus on helping to prevent diseases. Pet owners can help detect cancers early by regularly feeling for lumps on pets more than six or seven years old. She also recommends an annual ultrasound and chest x-ray.
Old Age For Dogs - Rough
Other ailments that afflict older dogs include heart disease, allergies, behavorial issues such as dementia, retinal disease and cataracts.
Merial is optimistic about a new treatment it's developing for arthritis, a second generation Cox 2 inhibitor that it says is more selective than Cox 2 inhibitors currently on the market. Merial is hopeful to receive FDA approval "sometime soon," according to Schultz.
Going beyond treatments for individual diseases, a new genome-sequencing project is under way that may yield a host of knowledge and eventual treatments for both canines and humans.
In June, scientists began to sequence the genome of the dog at the Whitehead Institute/MIT Center for Genome Research in Cambridge, Mass, a project that typically costs $50 million, according to Kerstin Lindblad-Toh, lead researcher for the project.
The first dog that will be sequenced is a female boxer, Tasha. Boxers are one of the breeds with the least amount of variation in its genome. The sequencing of Tasha is expected to be completed by June 2004.
Lindblad-Toh noted that dogs and humans have about 99% of their genes in common, and "dogs get disease just like we do."
Dogs Can't Talk, But Signal What's Wrong
Drug development for canines can present special problems, starting with the fact that the patient can't verbalize what is wrong. But vets know what to ask owners and what cues to look for, Schultz said.
Another problem is the number and size differences among breeds of dogs, from a Chihuahua, which generally weighs less than six pounds to a Newfoundland, which can tip the scales at 150 pounds. The vast differences create challenges in terms of appropriate dosages for each breed. The variety among dog breeds is far greater than among humans, according to Schultz.
Animals have been used for years as test subjects for developing human drugs. Researchers are now going back to old studies for data that can be used to create treatments for animals, said Dr. Steven Rowell, director of hospitals at Tufts University School of Veterinary Medicine.
The typical timeline from initial discovery to the marketplace for an animal medication can stretch over eight to 10 years, with about four to five years in the regulatory phase. The average cost to develop an animal drug is about $30 million, according to several industry experts. In comparison, development costs for a new human drug average $802 million, according to the Tufts Center for the Study of Drug Development.
It can take a long time for a pharmaceutical company to recoup the cost of developing a drug for dogs since these drugs aren't the blockbuster sellers that some human drugs are.
But Merial and Pfizer both insist they are strongly committed to the pet market.
Some industry experts say these drugs tend to be profitable because they can cost more than the equivalent human drug. That's because they're sold directly by veterinarians, rather than through the kind of prescription management plans that negotiate price discounts for human drugs. There are few insurance companies that cover pets, and none include prescription coverage.
老狗吃新药 但求长相伴
活到老、学到老，老狗都要学吃药。
随著兽医保健学的发展，及宠物主人不计成本地为这些长著毛的同伴花钱，狗的寿命正在延长，这刺激了对先进兽药的市场需求。
Pfizer Animal Health负责新药市场推广及业务发展的副总裁福克特?坎菲斯(Folkert Kamphuis)称，年老的宠物通常患有各种老年疾病。Pfizer Animal Health隶属辉瑞制药有限公司(Pfizer Inc., PFE, 简称：辉瑞公司)。
根据代表动物药物生产商的动物保健协会(Animal Health Institute)提供的最新数据，2001年宠物药物销售额达到16亿美元，3年激增了30%。
目前狗用处方药中最畅销的是辉瑞公司的Rimadyl及预防寄生虫的Revolution，Rimadyl用来缓解包括关节炎在内的各种疼痛症状。其他畅销药包括：Merial治疗寄生虫的Frontline及Heartgard，Merial是默克公司(Merck & Co. Inc., MRK)与Aventis S.A. (AVE)组建的合资公司。上述公司并未单独统计单个品种药物的销售状况。
宠物药物销售与整体药物销售相比只不过是沧海一粟，但潜在市场却异常巨大。2002年整体药物销售额超过1,922亿美元。根据美国防止动物虐待协会(American Society for the Prevention of Cruelty to Animals)的数据，美国家庭大约拥有6,000万只狗。美国宠物产品生产商协会(American Pet Products Manufacturers Association)公布，美国人2002年在宠物身上花费了295亿美元。
加利福尼亚大学兽药学院(University of California, Davis, School of Veterinary Medicine)助教切瑞?伦敦博士(Dr. Cheryl London)称，与人类一样，狗面临的头号杀手也是癌症。如果狗活到10岁以上，患癌症的机率就增至50%-60%以上。
Merial全球研发主管凯文?舒尔茨博士(Dr. Kevin Schultz)称，Merial正在研发阻止恶性皮肤癌的疫苗，此项研究正处于初级阶段。Merial正在与纽约思隆－克德林学会(Sloan-Kettering Institute of New York)共同进行此项研发。目前提供该疫苗上市的具体时间表还为时尚早。
加利福尼亚大学兽药学院助教切瑞?伦敦博士正在研究治疗各种癌症的方法，其中包括一种小分子抑制剂，用以阻断引发癌细胞增长的化学信号。
目前这种疗法已经处于在美国食品和药物管理局(Food and Drug Administration, 简称FDA)登记研究阶段。FDA是负责动物和人类药物审批及监督工作的机构。FDA并未对记者的置评要求予以回应。据伦敦博士称，辉瑞公司是该项目的合作伙伴。辉瑞拒绝披露任何关于在途研发药物的信息。
伦敦博士还指出，对预防疾病的关注日益加剧。宠物主人可以通过经常抚摸宠物，感觉年龄超过6、7岁的宠物身上是否有肿块。她还建议对这些宠物每年进行超声波及胸部X光透视检查。
狗的老年：怎一个难字了得
其他侵扰老狗的疾病还包括：心脏病、过敏症、痴呆等行为疾病、视网膜疾病及白内障。
Merial对其正在研发的治疗关节炎的第二代Cox 2抑制剂充满乐观，称第二代Cox 2比目前在市场上销售的第一代Cox 2针对性更强。Merial希望能尽快获得FDA批准。
除了对个别疾病疗法的研究外，新的基因组排序项目也正在进行当中，该项目可能会提供一系列新知识并最终提供针对狗甚至人的各种疗法。 6月份，科学家在麻省理工学院怀德海研究所基因体研究中心(Whitehead institute/MIT Center for Genome Research)启动了狗基因排序项目。据该项目研究主管克斯汀?林德布莱德(Kerstin Lindblad-Toh)称，此类项目通常耗资5,000万美元。
第一只被基因排序的是一只名叫塔沙(Tasha)的拳师母犬。拳师犬是一种基因变异较少的犬类品种。对塔沙的基因排序预计将于2004年6月完成。
林德布莱德指出，狗和人类的基因有99%是相同的，狗得的疾病和人类似。
语言障碍不成问题
舒尔茨博士表示，犬类药物研发可能面临诸多问题。第一个问题就是狗这种特殊患者不能说出哪里不舒服。但兽医知道问宠物主人什么问题，并获得诊断所需线索。
另外一个问题是狗的种类及身材各异，从体重通常低于6磅的奇瓦瓦犬到体重可达150磅的纽芬兰犬，不一而足。如此巨大的种类差异使确定每种狗适当用药量成为一项难题。舒尔茨博士表示，狗的种类差异远远大于人类之间的差异。
塔夫兹大学兽医学院(Tufts University School of Veterinary Medicine)医院主管斯蒂文?劳威尔博士(Dr. Steven Rowell)称，人们将动物作为研发人类用药试验对象已有许多年的历史，现在研究人员又开始翻出旧资料，从中寻找能用来创造新的动物疗法的数据。 据业内专家称，动物药物从开始研究到最终上市通常需要8-10年的时间，其中4-5年是处于监管机构审批阶段。每种动物药物的平均研发成本约为3,000万美元。而根据塔夫兹药物研发研究中心(Tufts Center for the Study of Drug Development)提供的数据，每种人类用新药研发成本平均为8.02亿美元。
但医药公司收回犬类用药研发成本的时间却通常较长，因为这些药与人类用药相比通常销量较低。
但Merial及辉瑞公司都表示，有责任开发宠物药物市场。
一些业内人士称，宠物药物将逐步开始赚钱，因为这些药物的价格通常比类似的人类用药高。因为宠物药物由兽医直接销售，而不是通过处方药管理系统进行销售。通过处方药管理系统销售的人类用处方药价格通常会要求制药商折价。现在很少有保险公司涉足宠物保健保险，根本没有保险公司承担宠物处方药物保险。
