Paclitaxel, marketed name Taxol, is among the most commonly used drugs in oncology in general, and definitely also for lung cancer, particularly NSCLC. The combination of carboplatin/taxol is the most frequently prescribed combination for advanced NSCLC in the US and is also employed in many other settings for NSCLC as well. However, there are several potential problems with taxol. It is extremely hard to dissolve and requires a solvent called cremaphor (polyethoxylated castor oil — don’t worry, it’s not on the test!) and special tubing, as well as a three hour infusion time, to administer in its most common schedule. Patients need to take multiple premedications that include steroids, which is a nuisance for lots of patients and a significant problem for some, such as those who have diabetes, because steroids can markedly increase the blood sugar levels of patients. And despite premedications, it’s not uncommon for patients to develop significant hypersensitivity reactions that can be quite serious and, rarely, fatal.

There are several novel formulations of paclitaxel and other chemotherapeutic agents that allow the same paclitaxel molecule to be delivered without the alcohol-based solvent, thereby eliminating the need for steroid premedications and a long “chair time” of patients having to spend most of their day getting chemo because it’s unsafe to give the chemo faster than that. One of these is nanoparticle (tiny little particles) albumin bound (or nab) paclitaxel, which has the scientific name ABI-007 but is commonly known as Abraxane. Not only is this special form of taxol faster to administer and doesn’t require the premedications that solvent-bound taxol does, there is also the possibility that this albumin-bound form may be delivered and picked up by the tumor than standard taxol. In fact, there is some evidence that Abraxane may be superior in some ways to standard paclitaxel in breast cancer, where it has been studied much more than it has been studied in lung cancer thus far. In a large trial with 460 predominantly (86%) chemotherapy pretreated women with breast cancer (abstract here), those who received Abraxane had a significantly higher response rate from Abraxane given every three weeks than standard taxol (21.5% vs. 11.1%), and they also had a significantly longer progression-free survival, but the overall survival was not significantly different. It also had a no hypersensitivity reactions from the Cremaphor solvent, and lower neutropenia rates and severity of neuropathy (although the neuropathy with Abraxane remains a significant side effect challenge). On the basis of this work, Abraxane was approved by the FDA in January, 2005 for recurrent or metastatic advanced breast cancer. Continue reading →