It can be a long and expensive journey taking an average of 12 years and over $350 million to get a new drug from the pharmaceutical research lab to your medicine cabinet. (To learn more about this epic journey, read How A New Drug Gets Approved.) But sometimes, even after winning regulatory approval, the drug turns out to be a complete loser in the marketplace.

Fierce Pharma lists these intriguing example of some of the biggest Big Pharma Phlops:  

1.  ROGAINE: manufactured by Upjohn, approved in 1986.

The promise: It’s 1986, and Time magazine is profiling a promising treatment for baldness. Upjohn, which later became part of drug giant Pfizer, saw great hope with minoxidil, until then a blood pressure treatment.

And the public was also hopeful. Time reported at the time:

“When a Washington hospital announced three years ago that it was seeking gleaming pates on which to test the hair restorer, 10,000 eager volunteers called in,  jamming the switchboard for three days and forcing the staff to use disaster control lines.”

What went wrong: The FDA took issue with Upjohn’s boasts about minoxidil, saying a company press release was “overly positive” and contained “misconceptions and false impressions of safety and efficacy.” But the press release had aided the company’s stock, which rose more than 9% to $174.25 in 48 hours. Upjohn’s minoxidil sales had climbed from $14 million as an anti-hypertensive drug in 1984 to $33 million in 1986.

However, as Money magazine reported in 1989, early reports of minoxidil’s benefits for balding men got blown out of proportion – aided in part by Upjohn’s publicity efforts. And U.S. sales failed to grow despite the FDA’s decision to let Upjohn market minoxidil as the prescription drug Rogaine. Sales were slow because Rogaine worked best for a younger men with thinning hair, but not so much for older men with receding hairlines.

Among the reasons cited for the low domestic annual sales of just $11 million was Upjohn’s vague, $20-million direct-to-consumer advertising campaign, featuring a man walking along a beach with the “See your doctor!” suggestion.

Rogaine eventually went OTC (available over the counter without a prescription), but it faced generic competition sooner than anticipated.

2.  RELENZA: manufactured by GlaxoSmithKline, approved in 1999.

The Promise: Relenza (zanamivir) was developed by Australian biotech Biota before being licensed to GlaxoSmithKline in 1990. After its approval in 1999, flu pandemic fears began to spread as the avian flu captured the public’s attention. As one of only two pandemic flu drugs approved by the FDA – the other being Tamiflu – Relenza was set for mega-blockbuster sales.

What went wrong: Despite its better efficacy rates compared to Tamiflu, as well as its lower price, Relenza had too many warnings. The powder-form, administered via a “diskhaler,” aggravated respiratory problems in some patients.

Plus, Tamiflu’s pill and liquid systems were approved for patients as young as two years old, while Relenza was approved only for those over seven. Relenza was approved for use only as a treatment for influenza, whereas Tamiflu could be taken as a preventative measure.

But Relenza’s sales never matched its competitor’s. In 2006, Relenza gained just $13 million in revenue, compared to Tamiflu’s $770 million in the first half.

In a show of good will at the start of the H1N1 flu scare, Roche donated 30 million doses of its Tamiflu to the World Health Organization stockpile, and the drug was widely touted by agencies and doctors alike as prescription for swine flu (H1N1).

Read the rest of the Fierce Pharma article to see the other ‘phlops’ on their list.