The wait was a little longer than anticipated, but investors finally got a healthy first look at data from InterMune's (Nasdaq: ITMN) hepatitis C treatment, ITMN-191, on Tuesday.

ITMN-191 is InterMune and partner Roche's antiviral protease inhibitor to treat hepatitis C virus (HCV) infections. It was discovered by Array BioPharma (Nasdaq: ARRY) and subsequently out-licensed to InterMune, which then out-licensed it again to Roche.

Almost six years ago the FDA approved an important new compound to help treat HCV, which is very dangerous and can lead to liver cancer. Without a doubt there will be more in the coming years. With the success of other, similar antiviral compounds in clinical testing, many people have been eagerly awaiting ITMN-191's first study results.

ITMN-191 against the competition
Thankfully InterMune released enough clinical trial data on Tuesday and Wednesday for us to be able to make initial comparisons of ITMN-191 against its brightest competition.

So how strong is the ITMN-191 data? Here's how its 14-day phase 1 study results compare to some other hepatitis C antiviral agents after their phase 1 14-day monotherapy studies in genotype 1 HCV-infected patients.



HCV mean viral
load reduction (VLR)

InterMune and Roche


3.8 log* median VLR

Vertex Pharmaceuticals (Nasdaq: VRTX)


4.4 log** median VLR

Pharmasset (Nasdaq: VRUS) and Roche


2.7 log*** mean VLR



4.1 log* median VLR

Schering-Plough (NYSE: SGP)


2.1 log^*** mean VLR

*In previously untreated patients only. **Both previously untreated and treatment-experienced patients. ***In treatment-experienced patients only.
^Not necessarily at end of study.

This is not a full list of top HCV drug treatments in development. Other compounds, such as privately held ViroChem's polymerase inhibitor, have produced similarly strong study data.

Another important factor is that all these phase 1 studies used at least slightly different patient groups in various locations. Differences such as age, sex, or ethnicity affect how well a drug performs. All these drugs were tested in very few patients in these studies; some cohorts had fewer than 10 patients.

It is still too early to guess which drug candidate looks most effective. Based on these results, all I'd be confident to say is that they all exhibit some activity in fighting hepatitis C. Even a 2.0 log reduction in a patient's HCV loads represents a 99% reduction in the amount of the virus in the bloodstream.

The reason I compare ITMN-191 to the other leading anti-hepatitis C treatment candidates is to show that the drug's phase 1 results are at least comparable to other similar compounds that are much closer to approval. (If telaprevir doesn't get approved I will be beyond shocked.) InterMune has now officially validated ITMN-191 as a viable anti-hepatitis C drug candidate at this stage of the game.

InterMune will start testing ITMN-191 in another phase 1b study this quarter, this time in combination with Roche's Pegasys and ribavirin. The real test for ITMN-191 will be in how the drug performs in long-term testing, and whether it can produce HCV cure rates as high as some of its advanced rivals.

Investors shouldn't forget that other HCV antivirals from Wyeth (NYSE: WYE), Achillion, and Gilead Sciences (Nasdaq: GILD) have been derailed due to negative safety signals. ITMN-191's long-term safety in humans is still unknown.

Quality, not quantity
ITMN-191 is not InterMune's only exciting pipeline candidate, and investors will hear more about its potential idiopathic pulmonary fibrosis treatment, pirfenidone, by January next year when InterMune releases phase 3 results for the drug. 

InterMune doesn't have the biggest drug pipeline; only two compounds are in clinical stage testing. Its two drug candidates don't treat the biggest potential markets in the world. But I can say with confidence that InterMune does have two very viable shots on goal with ITMN-191 and pirfenidone, and both have produced very exciting data so far.

If InterMune can manage its $235 million in cash wisely and grab additional funds when appropriate, all it would need is one of these compounds to make it to market for its current market capitalization around $700 million to look cheap.

Pirfenidone will represent InterMune's first shot on goal with its phase 3 study results coming out so soon and a potential marketing application around the middle of next year. Investors won't have to wait long to see whether InterMune can score a goal.