There are few diagnoses in the world that cause as much fear in patients as hearing the word "cancer." Cancer is now the second-leading cause of death in the U.S., trailing only heart disease, according to the Centers for Disease Control and Prevention.
While long-term solutions exist for heart disease with regard to the lowering of its biggest risk factors such as high cholesterol and diabetes, cancer treatments -- depending on the type of cancer, of course -- offer far less long-term hope. But, that soon may be about to change.
As I chronicled during the Tackling Cancer series, newer technologies, falling research costs, and revolutionary new medicines are extending the long-term survival rates for multiple cancer types. Prostate cancer is a shining example of how increased education and awareness, as well as better quality medicine, has improved the quality of life and outlook of patients, pushing the five-year survival rate from 68% in 1975-1977 to nearly 100% in 2002-2008.
We've also seen a nice bump higher in multiple myeloma, a form of blood cancer that develop by from B cell lymphocytes by overproducing plasma cells and crowding out normal blood-producing cells. The five-year survival rate has jumped from just 25% in 1975-1977 to 43% as of 2002-2008. However, there's still a lot of work left to be done with survival rates of only 43%.
The current standard of treatment
Celgene's (NASDAQ:CELG) Revlimid is the current shining star of multiple myeloma. Approved in 2006, Revlimid met its primary endpoint of extending time-to-progression when taken with dexamethasone in the first of two studies (median TTP of 37.1 weeks compared to just 19.9 weeks for the dexamethasone control arm). Sales of the drug have really taken off and accounted for $3.8 billion of Celgene's nearly $5.4 billion in product sales in 2012.
The newest treatment on the block is Onyx Pharmaceuticals' (NASDAQ: ONXX) Kyprolis, which was approved last year as a treatment for multiple myeloma patients who had failed to respond, or stopped responding, to two previous treatments. The accelerated approval of Kyprolis was based on its overall response rate of 22.9%. While it delivered a median response duration of 7.8 months, it also came with a laundry list of side effects, with serious adverse events reported in a whopping 45% of patients.
There could be a new sheriff in town
Although these two drugs offer promise to multiple myeloma patients that did not exist just decades ago, further research is needed to extend the effectiveness of drugs and improve quality of life. One means to that end could be through the exploitation of CD38, an ectoenzyme expressed throughout certain cells of the body, including B lymphocytes. CD38 is highly expressed on the surface of multiple myeloma solid tumors and may aid in their destruction.
Last year, Genmab announced a licensing agreement with Johnson & Johnson's (NYSE:JNJ) subsidiary Janssen Biotech, which could result in payments and royalties worth as much as $1.1 billion for its CD38 program. The lead drug in that program, daratumumab, received the rare and highly coveted breakthrough therapy designation for double refractory multiple myeloma from the Food and Drug Administration following outstanding phase 1 results in early May. Designed as a treatment following at least three previous therapies, daratumumab delivered a benefit to 47% of patients with a 67% response rate at a dose of just 4 mg/kg.
Just yesterday, Celgene delivered the exciting news that it, too, would be partnering up in an effort to develop multiple myeloma treatments targeted at CD38. In a licensing and milestone deal that could be valued up $818 million, Celgene partnered with MorphoSys on the development of MOR202, a clinical-stage treatment for relapsed or refractory multiple myeloma. Celgene will share costs with MorphoSys on a 2/3 to 1/3 basis and hopes to repeat or better the early success of daratumumab.
CD38-targeted therapies could also have applications well beyond multiple myeloma including diffuse large B-cell lymphoma and chronic lymphocytic leukemia to name a few.
The one downside, though, to CD38 is that it's also expressed in healthy cells, meaning any treatment targeting CD38 is going to destroy healthy cells and cancerous cells. This creates a pretty tricky dilemma when it comes to dosing options -- too little and it won't eradicate much of the tumor; too much and you could kill a significant number of healthy cells and make the patient even sicker.
There's still quite some time left for CD38 therapies to play out in clinical trials, but from what I've seen so far, these treatments merit a watchful eye, as they could be the future pathway for multiple myeloma care.