Wednesday, March 21, 2012

Should a Chemo Drug That Doesn't Prolong Life Be Approved?

Being a touch late to the social media game, the Billy Rubin Blog just got its own Twitter page up and running this week (follow us!) and started happily chirping away about medical issues. Having never lived more than five minutes of my life according to Polonius's dictum that brevity is the soul of wit, I wasn't sure how Twitter and I were going to match up.

Yet lo, first day in, I see a very interesting tweet from USA Today Health dealing with the FDA approval of the GlaxoSmithKline drug pazopanib (trade name of Votrient™) for use as a "salvage" chemotherapy agent for people with a type of cancer known as a soft-tissue sarcoma. Votrient had already been approved for use in renal cell carcinoma, but in seeking approval for the sarcoma indication, GSK was seeking to expand Votrient's market: while any doc could legally prescribe Votrient for a sarcoma patient as an "off-label" medication, insurance companies would not be likely to pay its steep cost (as this cost analysis demonstrates for one health plan, Votrient can run up to $7,000 a month).

What made the article interesting and worthy of tweeting is that GSK was unable to demonstrate that Votrient actually prolonged the lives of the affected patients. GSK measured the drug's effectiveness in two ways: one by looking at survival, but two, by looking at something called "progression free survival"--or how long the tumors stay suppressed. The FDA summary notes: "median progression free survival was 4.6 months in the pazopanib arm and 1.6 months in the placebo arm...however, this improvement did not translate to an improvement in the overall survival...the median overall survival was 12.6 months in the pazopanib arm and 10.7 months in the placebo arm." [my emphasis]

So off I tweeted "FDA approves new GSK chemo med, but drug doesn't prolong life. Umm...then what good does it do?", which I thought a succinct summary that required not much further explanation. Later in the evening I felt my own twitter of delight when someone from parts unknown replied to my tweet, though delight morphed into mild disappointment when @JLM_drivel's reply was "r u joking? it says what it does, prolongs illness-free life. obv not grt drug bt may or may not be worth it". Such are the limitations of Twitter: hard to have a meaningful discussion in 140 characters or less. But no, I wasn't joking.

Look--GSK has what seems to be a very intriguing and promising drug on its hands. That it appears to have decreased tumor size indicate it has potential to be a useful adjunct chemo agent, or even with some molecular tweaking to be a beneficial drug in its own right. But a salvage chemotherapeutic drug that doesn't prolong life can't be described as "may or may not be worth it". It's not worth it! It isn't worth it at any price, but it most certainly isn't worth it at $7000 a month for 11 months.

If every patient annually diagnosed with soft-tissue sarcoma (about 10,000) took Votrient for that length of time, GSK would gross $770 million. Not a bad day's work for a drug that doesn't prolong life.

Not only is this not worth it, it has the potential to erode patient confidence in the system that's working to treat and maybe one day cure them. As this Bloomberg news piece notes in quoting doc Gary Schwartz, the head of the sarcoma service at Memorial Sloan-Kettering in New York, "if the patient comes to the oncologist with cancer, they want to be cured...but with sarcoma, they aren't cured, they want to live longer." They want to live longer. Votrient cannot deliver that, and if these very vulnerable patients take this drug without getting that in return, they and their loved ones will feel cheated by taking it.

That was what I meant when I asked "what good does it do?"--and until GSK can show that Votrient can prolong the life of these sarcoma patients, the answer will be "not much, progression-free survival be damned."
--br

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