Compared to FOLFIRINOX, Abraxane appears to cause less severe vomiting, diarrhea and febrile neutropenia, a sign of infection. However, Abraxane is responsible for more severe thrombocytopenia (low platelets) and sensory neuropathy, or nerve damage, in the arms and legs, than FOLFIRINOX
Febrile neutropenia and sensory neuropathy are the most worrisome side effects for each drug, with good reason. An infection with a low white blood cell count can kill, and persistent, severe tingling of the hands and feet can meaningfully impair quality of life. (Consider Celgene's Thalomid and
Velcade, both of which have been hindered commercially by a tendency to cause sensory neuropathy.)
The most common pushback against FOLFIRINOX becoming widely used in pancreatic cancer is that the regimen is too toxic for patients to tolerate. I don't think that's true, at least for relatively healthy patients. Nevertheless, Abraxane's side effects are worth keeping an eye on.
The most significant hindrance to FOLFIRINOX's adoption in the pancreatic cancer treatment landscape may be the simple fact that the four drugs in the regimen are all generic, meaning no company is out there actively marketing it to doctors.
Celgene, however, will be marketing Abraxane aggressively to pancreatic cancer specialists, if approved. The company's salesforce will likely be able to assuage concerns about Abraxane's toxicity, suggest appropriate patients for initial use, and highlight potentially compelling details in the dataset -- such as the possible correlation between high levels of secreted protein acidic and rich in cysteine, a membrane protein known as SPARC, and longer median survival.
There is one point of concern that makes me a little nervous. Based on an interim analysis, the independent monitors overseeing the Abraxane pancreatic cancer study recommended to Celgene that the trial increase in size by nearly 34%. That's potentially important, as it could indicate the data monitors saw a smaller-than-expected benefit for Abraxane versus control during the interim analysis. It's more likely that I'm being too much of a worrywart.
In aggregate, the data suggest Abraxane will have favorable risk-benefit profile in pancreatic cancer. Current analyst consensus estimates include only roughly $730 million in 2015 Abraxane sales across all indications, well below management's guidance of sales reaching $1 billion to $1.25 billion. That suggests most Street analysts don't expect the drug to work. Clearly, success in phase III would force those projections upwards.
Time will tell.
Two related notes: Read Jim Silverman's column on buying the
Celgene contingent value rights
bullish trade tied to the positive outcome in the Abraxane pancreatic cancer trial
If Abraxane demonstrates a clinically meaningful survival benefit in pancreatic cancer,
(THLD - Get Report)
pancreatic cancer drug
TH-302 could be obsolete
even before its phase III study is completed.
Sadeghi has no position in Celgene.
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