hypothetical prices with analysts in the past as they try to get a handle on the market opportunity. Potential patients number 6,000 to 8,000 in the U.S., plus a similar number in Europe, according to Seattle Genetics market research. If the drug cost $45,000 to $50,000 per year, it could generate $300 million to $400 million in sales, Siegall told me in June 2008.
Over the weekend, Siegall said “it could command a premium price” based on the strength of the clinical trial data, although it’s still too early to set the actual price. This is one of the important questions Seattle Genetics will have to work on in the year ahead, along with other key tasks to complete. The to-do list will include getting the FDA application ready, preparing for an FDA advisory panel meeting, presenting at medical conferences, building up manufacturing inventory, and continuing the momentum with enrollment in early stage trials. Siegall talked with me about this all-out commercial push, and how Seattle Genetics was getting ready to handle all this work, in a feature story about the company’s growth in May.
Today’s results validate the long-term technology strategy of Seattle Genetics: to make targeted antibody drugs. The company was founded in 1998 with technology that Bristol-Myers Squibb gave up on: genetically engineered Y-shaped proteins that can be made to hit certain targets on cancer cells, while mostly sparing healthy ones. That is a big advantage over traditional chemotherapy that can be brutal on healthy cells and cause nasty side effects.
But many antibodies have failed over the years. While they might interfere with tumor growth and proliferation, they sometimes lack the potency to create a true knockout punch. For three decades, scientists have tried to add toxins to the antibodies to essentially create targeted chemotherapy, with very little to show for it. Earlier generations of these so-called “antibody-drug conjugates” failed, often because the toxin would break off in the bloodstream before it could reach the intended target. Wyeth (now part of Pfizer) introduced the first “empowered antibody,” gemtuzumab (Mylotarg), back in 2000, but it was a commercial dud because of its side effects, and Pfizer recently pulled it off the market.
Seattle Genetics has sought to improve on drugs like that through the years with a “synthetic linker” technology that keeps the antibody and toxin stable in the bloodstream, releasing the potent payload only into the tumor. The Seattle Genetics technology has been licensed for development on certain cell targets by a number of major pharma and biotech companies, such as GlaxoSmithKline, AstraZeneca’s MedImmune unit, Daiichi Sankyo, Bayer, and Roche’s Genentech unit. Seattle Genetics has retained exclusive rights to the technology’s use in hitting specific targets, and two other candidates against those targets are now in clinical trials.
Roche’s Genentech unit, the world’s leading maker of antibody drugs, has been in hot pursuit of this same concept for years, and also has produced some strong results with a more potent version of its pioneering breast cancer antibody, trastuzumab (Herceptin). That new potent antibody, called T-DM1, uses a different linking technology provided by Waltham, MA-based ImmunoGen (NASDAQ: [[ticker:IMGN]]). T-DM1 has been at the forefront of development for such empowered antibodies although the drug hit a bump in the road in August, the FDA said it wouldn’t review a Genentech application until it sees results from a more thorough test.
That setback for Genentech means that Seattle Genetics could be in position during 2011 to establish the new paradigm of empowered antibodies. If this drug is cleared by FDA, it will send a ripple effect through the biotech industry, given that “naked antibodies” that lack the extra degree of potency already make up a market worth an estimated $30 billion a year. Once the first of the new empowered antibodies hits the market, analysts will be busy sizing up the pipeline of more to come in the industry, and projecting all new growth curves for this class of drug.
“We think ADC [antibody-drug conjugate] technology is here to stay, and it could be really important for cancer patients and potentially transformative,” Siegall says. “These data establish us as the leaders in ADC technology. We are certainly not going to be sitting back and watching. We are going to push hard and make sure we provide the most promising opportunities for patients with limited therapeutic options.”
From a business perspective, Siegall is dreaming big. “We are now in position to transition from an R&D company into a commercial company. We’re looking forward to growing this company, and building an important biotech company. What’s an important biotech company; how do you define that? To me, it’s a company that makes products that patients really need.”
