The path traveled by Geron (GERN -1.07%) has never been easy. For 20 years the company has gone through continuous fits and starts, taking investors on a wild ride that unfortunately (so far) has brought dashed hope.

With shares hovering around decade lows, let's look at why Geron has tumbled this year and whether there might be value lurking in this stock.

Source: Geron.

First, a bit of background
Geron's latest stumble follows a dramatic doubling last year tied to enthusiasm over the company's imetelstat, a drug that previously failed in trials for breast cancer but showed promise for patients suffering from myelofibrosis, a form of chronic leukemia.

In a small, early stage trial last year involving 18 people, four patients taking imetelstat went into complete remission, one went into partial remission, and three others saw improvement.

That news sent shares flying, but the frenzy proved short-lived. In March, the FDA yanked the emergency brake on imetelstat trials after discovering that patients treated with the drug might be at risk of long-term liver damage.

Liver toxicity is a common problem for drugmakers (and a big reason Organovo is working on bioprinting liver assays for pre-trial testing), and investors fear the FDA hold could spell the end for imetelstat.

Springing eternal
Roughly 90% of all drugs fail in clinical trials, so it's not surprising to see imetelstat struggling. But the difference  is that many biotech companies have other treatments in trials to fall back on. At Geron, imetelstat may be the company's last, best chance at a big win.

As a result, the stakes are high to overcome the FDA's concerns and jump-start imetelstat trials. In that regard, the company has received some encouraging news: In July, the FDA lifted a separate partial hold on an imetelstat trial underway at the Mayo Clinic.

Previously, the FDA had asked Mayo to halt imetelstat's use unless patients in the trial were already responding to the drug. Mayo was also tasked with demonstrating to the agency the reversability of any liver damage that might be caused by imetelstat.

Since the FDA has lifted that partial hold on the Mayo study, it would appear the clinic was able to satisfy the regulator, and that might indicate Geron could similarly win over the agency regarding its own in-house trials.

Long shot might be an understatement
Imetelstat's importance to Geron can't be overstated. The drug's impressive early stage showing in myelofibrosis suggests that if Geron can overcome FDA objections, it could one day compete in a treatment market worth hundreds of millions of dollars.

Even if Geron can unlock the clinical hold, trials are still in the early stages, indicating imetelstat could be years from commercialization if approved. For that reason, I'll stay on the sidelines on this one until there's more clarity.