Given that Fanapt launched in January, assume that most of the $21 million in Fanapt revenue is actually wholesaler inventory stocking and not actual patient demand for the drug.

Prescription data from IMS bears this out. A total of 2,359 total prescriptions were written for Fanapt from January through the end of March, according to IMS Health. At a price of approximately $600 per prescription, that implies Fanapt end-user sales of $1.4 million. (I don't subscribe to IMS' prescription drug data, but the Fanapt numbers were provided to me by a fund manager who does.)

Two ways of looking at this situation: If you're a Vanda/Titan bull, the $21 million in Fanapt revenue for the just-completed quarter, even though most is inventory stocking, suggests that Novartis is gearing up for heavy end-user demand and the company believes that the Fanapt launch will go well.

If you're a bear on Fanapt and these stocks, you look at the IMS data and say patient demand for the drug is weak, and therefore, the next few quarters of sales must come from inventory de-stocking. This means the $21 million in quarterly sales will be a high water mark for the drug and won't likely be reached again for quite some time.

I received an email dump of epic proportions after my dissection of the Serdaxin depression data from Rexahn Pharmaceuticals ( RNN) this week. Most of the responses were the shrieking harpy variety, but not all, including Rex W. who writes, "I understand why you're focused on Serdaxin but the great thing about Rexahn is that it's working on lots of drugs. I think the stock moves higher as Rexahn gets ready to release data on its other big drug, Zoraxel for erectile dysfunction."

I have little doubt the penny stock promoters will be working overtime to move Rexahn higher in front of whatever Zoraxel data awaits, but be forewarned that Serdaxin and Zoraxel are the same drugs. The active ingredient in both is clavulanic acid, the old antibiotic-boosting agent.

I argued persuasively for why investors should look askance at the Serdaxin data in depression, so color me equally skeptical about Zoraxel in erectile dysfunction.

If and when Rexahn does provide investors with Zoraxel data, let's hope the company is more transparent than it was this week with the Serdaxin results.

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