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发表于 2007-3-25 04:47:26
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来自: 美国
<p>just like other new drugs quickly approved and rushing to the market due to China's loose regulation and high demand, Endostar has not shown its promising results. I doubt it will pass the FDA in the states. Below is an article of 2005 about the origin of this drug and how Endostatin ends in the US. I hope it will help you guys who are using this drugs or are considering using this drug. My dad does not have any side effects from Endostar. Ironically no doctors even in those top hosipitals know how to use it and how to evaluate its performance. It is a very expensive drug and not many Chinese can afford it. To my impression, this drug might be helpful to some patients, but it should go through more human trials so more patients can receive free treatments until its more accurate result comes up. I guess the company does a very good marketing job. Instead of providing free trial, it only offers paid 'human trials'. </p><p></p><p><a href="http://www.post-gazette.com/pg/05356/626533.stm">http://www.post-gazette.com/pg/05356/626533.stm</a> </p><h2>Cancer drug finds new life in China</h2><p style="TEXT-INDENT: 0px;">Thursday, December 22, 2005</p><p>By Kathy Chen in Yantai, China, and Amy Dockser Marcus in Boston, The Wall Street Journal<br/></p><p></p><p>When pioneer researcher Judah Folkman's widely hailed cancer drug fell short in human trials, Luo Yongzhang was among the many who were disappointed. Dr. Luo had invested several thousand dollars in EntreMed Inc., the small company making the drug, and lost most of it. </p><p>Today, the entrepreneurial Chinese biochemist believes he has rescued Dr. Folkman's dream. Dr. Luo says an improved version of the drug, developed by his company, has shown promising results in Chinese human trials, and he hopes to bring it to patients in the U.S. </p><p>It is the latest surprising chapter in a saga that goes back to the 1960s, when Dr. Folkman first came up with the idea of treating cancer by choking off tumors' blood supply. He was largely vindicated in February 2004 when the U.S. Food and Drug Administration approved Avastin, a cancer drug based on this principle. But Avastin is sold by Genentech Inc. Shortly before Avastin's approval, EntreMed gave up on Dr. Folkman's own discovery, a drug called endostatin, citing the high cost of making it. </p><p>Now the 72-year-old cancer researcher at Children's Hospital Boston has revived his hopes of bringing his discovery to patients. The new version of endostatin, he says, is "an enormous achievement on the part of Prof. Luo." </p><p>Dr. Luo says his new drug, which he calls Endostar, "could be a revolution, and the Chinese government recognizes this." He says his company is in talks with several major U.S. pharmaceutical companies about licensing Endostar, which was approved by Chinese authorities in October, for use in the U.S. He declines to name the companies. </p><p>His prospects are of particularly high interest to four American cancer patients. They continued taking endostatin after commercial development of the drug ended. This year, their supply of endostatin ran out. Two of them aren't taking anything to replace it, and one of the two who switched to Avastin is suffering from side effects. "Endostatin has been very, very good to me," says Ted Bielawski, 59, who hopes to get Endostar. </p><p>The hurdles to getting Endostar approved for general use in the U.S. are high. It has only been tested in China, and it's not clear whether those trials meet U.S. and European standards. The results of the trials have yet to be published in any Western peer-reviewed medical journals. The exact mechanism by which Endostar inhibits tumors from building a blood supply is unknown. </p><p>Manufacturing the new drug is tricky -- especially for a small, young Chinese company that is short of funding. Dr. Luo, who teaches full-time at Beijing's prestigious Tsinghua University in addition to being company president and chief scientist, is working with his Chinese partners to expand the company. Also, Children's Hospital, which holds endostatin patents, says it would want to speak about licensing issues to anyone who seeks to sell Endostar in the U.S. </p><p>In his long career, Dr. Folkman has come up with several new drugs that, despite their promise, have failed to make it to the market or are still being studied. That's par for the course in cancer. When he and his colleagues discovered endostatin, it was a sensation that riveted the medical world and raised hopes among thousands of patients -- although Dr. Folkman himself was always careful in discussing its prospects. The doctor combines his enthusiasm for Endostar with caution that the drug must be tested successfully on humans in the U.S. if it hopes to have a chance of gaining FDA approval. </p><p>Dr. Folkman has been testing Endostar on mice in his lab and says it appears to be more potent than endostatin. He is seeking the FDA's nod to provide Endostar on a compassionate basis to the four longstanding patients. </p><p>Dr. Luo's discovery has attracted high-level notice in China. The country is hoping to build industries that rely on skilled talent, not just cheap labor, partly by encouraging Chinese who have studied overseas, such as Dr. Luo, to return home. Chinese President Hu Jintao visited Dr. Luo's company in the northeastern city of Yantai in April, and the venture has received more than $6 million in interest-free loans and government grants. </p><p>Cancer rates are surging in China, placing strains on its underfunded health-care system. About 1.5 million Chinese die from cancer each year, according to China's Ministry of Health, compared with about 700,000 in the 1970s. Between 2000 and 2005, the number of lung-cancer patients in China jumped an estimated 32 percent. Breast-cancer rates have also surged. </p><p>The middle son in a family of seven children from an impoverished village outside Yantai, the 43-year-old Dr. Luo was the only one to attend college. He says he promised a college friend who died of pancreatic cancer at 22 to devote himself to seeking a cure. After receiving a doctorate in biochemistry from the University of California, Berkeley, and doing postdoctoral work at Stanford and Harvard universities, he settled on a project: improving endostatin. </p><p>The drug is a natural protein produced in small quantities by the human body. Reproducing it in the lab using genetically engineered bacteria was a challenge for Dr. Folkman in the 1990s. The long chains of amino acids that make up the protein tended not to fold into the proper three-dimensional structure, and it was quick to degrade in the body. Dr. Folkman later switched to yeast and EntreMed was able to produce endostatin, but this method was extremely expensive. </p><p>rotein folding was Dr. Luo's area of expertise at Stanford. He read papers about the well-publicized drug, including one in which Dr. Folkman described endostatin's structure. "My intuition was that (endostatin) should work," Dr. Luo recalls. "I felt we could improve it." </p><p>In June 1999, Dr. Luo and Yantai R.C. Pharmaceutical Co., a maker of traditional Chinese medicines, set up a joint-venture company, with the company agreeing to invest $1.23 million for a 55 percent stake. Dr. Luo and several other Chinese scientists put in their know-how for 45 percent. On a rainy November day, Mr. Luo boarded a plane from San Francisco to return to his native country. Eight other Chinese overseas students eventually joined him. </p><p>Dr. Luo still remembers Christmas Eve in 1999, shortly after he succeeded in folding the protein properly. He was still using bacteria to make the drug but added extra amino acids to make it more stable. That night, a power outage cut off electricity to the lab, where precious drug specimens were kept in a freezer. Dr. Luo trudged into the knee-high snow to connect extension cords from an apartment into the lab freezer, and his feet got frostbitten. </p><p>Trials between 2001 and 2004 on 493 Chinese patients with non-small cell lung cancer -- the most common kind -- showed that 35.4 percent of patients who received Endostar along with chemotherapy saw their tumors shrink substantially, compared with 19.5 percent for those who received just chemotherapy. The results were reported at a major U.S. cancer meeting in May by Sun Yan, a cancer specialist at the Chinese Academy of Medical Sciences who oversaw the clinical trials. The one-year survival rate for patients on Endostar was about 60 percent, double the rate for those who got chemotherapy alone, Dr. Sun says. The results haven't been reported yet in a Western medical journal. </p><p>David H. Johnson, a lung-cancer specialist who is deputy director of the Vanderbilt-Ingram Cancer Center at Vanderbilt University, attended the presentation and says the data raised some skepticism, in part because about half of the patients in the trial had a less-advanced stage of lung cancer. The survival rate for patients in the non-Endostar group seemed low given the inclusion of less-advanced cases, he says. </p><p>"These are tell-tale things that say to you that maybe the data is not as solid as you'd like," says Dr. Johnson, adding that the results are intriguing enough to warrant a more-rigorous trial in the U.S. </p><p>Dr. Sun said, however, that the 30 percent one-year survival rate is normal. </p><p>Back in Boston, Dr. Folkman had no idea that Chinese scientists were working on his drug until the May presentation. Through a Chinese-born scientist who formerly worked in his lab, Dr. Folkman made contact with Dr. Luo and received some samples of Endostar to test in mice. </p><p>Dr. Folkman immediately thought of trying to get Endostar for four American patients who were still taking endostatin. All four had advanced neuroendocrine tumors and enrolled in a clinical trial in 2001 at the Dana-Farber Cancer Institute in Boston. </p><p>EntreMed, the small Rockville, Md., company that made endostatin, had seen its shares soar briefly in 1998 as investors such as Dr. Luo bet on the drug's success. But human trials in 193 patients showed mixed results. In the neuroendocrine-tumor patients, 38 of 42 patients stopped using the drug by this year because it wasn't working for them. </p><p>In February 2004, EntreMed gave up on the drug and returned the U.S. rights to Children's Hospital Boston. EntreMed cited the high cost of making endostatin for its decision. By August of this year, remaining supplies of endostatin ran out. </p><p>That left the four surviving patients in a bind that is increasingly common as the number of drug trials grows. If only a small number of patients improve, a company often won't spend huge sums on more tests. "We were told that endostatin was dead because there wasn't enough evidence it could cure us," says Anita O'Brien, 63, who worked as a nurse until a year ago. "But the drug stabilized us, and we had normal lives. That's enough for us." </p><p>As Dr. Folkman convened the patients in a Children's Hospital conference room in August, Nancy Hawkins, 56, was worried. "I have three grandchildren, I work as a nurse, I go to church," she said. "Am I going to be able to still do all that on another drug? Will I feel as good as I feel now if I have to switch drugs?" Dr. Folkman told the four he was excited about Endostar's potential, but he wasn't sure when it would be available for them. </p><p>Three months later in November, Dr. Folkman met again with the four patients. The cancer was stable in all four, but some had unsettling experiences without endostatin. </p><p>Within 10 days of taking her last dose of endostatin, Ms. Hawkins's face turned beet red. Her body felt hot and her ears burned, perhaps because the drug wasn't around to mitigate the noxious effects of her tumor. She started taking Avastin, and on her third infusion of the drug she suffered shortness of breath and tightness in her chest. She stopped that infusion midway through but managed to get through the next one. Another patient, Mr. Bielawski, was flushed and much redder than the last time the four met. He wasn't taking Avastin. </p><p>Scott Toner, 36, who works in the risk department of Fidelity Investments in Boston, said he was feeling fine on Avastin. When Mr. Toner was first diagnosed with cancer, he was 31 years old and unmarried. He didn't save a cent or think of marriage, figuring he was going to die soon. But when he took endostatin, his tumor remained stable. A year after going on the drug, he started dating his future wife. </p><p>At the November meeting, Mr. Toner passed a digital camera around the table with pictures of his newborn son. "This is the first endostatin baby," Dr. Folkman said with glee. The group pressed the doctor about the new drug. Dr. Folkman had some good news: He had received a supply from China, and it appeared safe and effective in tests on his lab mice. But the FDA would have to give approval for the four to receive Endostar. </p><p>Dr. Folkman says he has discussed the matter informally with an FDA official but hasn't submitted a formal application for permission. </p><p>If that permission comes, Dr. Luo will have opened the U.S. market a crack, but turning his discovery into a real business remains a challenge. Yantai Medgenn, the joint-venture company, needs nearly $20 million to build a new lab and factory that could produce Endostar on a mass scale, says Yantai R.C. Chairman Wang Weidong. </p><p>In mid-November, Dr. Luo took time out from his university job to visit Yantai. Striding by a room in which workers in face masks spend the day channeling Endostar proteins through purification machines, he pointed to large tanks in the back of the room. "We can produce one kilogram of (Endostar) in two weeks," he bragged, noting that researchers in the U.S. would pay around $600 for one-millionth of that amount of endostatin. </p><p>At a meeting of Yantai Medgenn executives, a production manager complained that her staff lacks adequate quality-control training. Dr. Luo cut her off: "I don't want to hear any of this. It makes me annoyed. Big Western pharmaceutical companies wouldn't do this." He explained later that he was irked because the manager waited to bring up the problem until just before a Chinese government inspection. </p><p>The inspection took place earlier this month. Dr. Luo says the company was informed that it passed but the official written notification isn't expected until late February or early March. Only after that will the company be permitted to sell Endostar in China. </p><p>Dr. Luo, known as "Boshi," or "Doctor," around the company, and his Chinese partners have sometimes disagreed over how to run Yantai Medgenn. They're debating how much to charge for Endostar in China, where the cost of cancer treatment is far beyond the means of the average worker. Dr. Luo and Mr. Wang agree on one point: Their company needs outside investors to provide capital for expansion. </p><p>atents are another issue. Dr. Luo and his colleagues have applied for two U.S. patents covering Endostar and its manufacturing process. However, because Endostar replicates much of endostatin's structure, it may brush up against patents held by Children's Hospital. In a statement, the hospital says it has patents that cover methods of making an "endostatin protein" and using it to treat cancer and other diseases. </p><p>"Endostar would be considered a form of an endostatin protein," says Leslie Grushkin-Lerner, a licensing manager in the intellectual property office of Children's Hospital. If someone wishes to sell Endostar in the U.S., she says, "we recommend that they talk with us about licensing opportunities." </p><p>Dr. Luo says he hopes Yantai Medgenn can license Endostar to a U.S. partner, and that partner could work out a deal over patents.</p> |
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