SAN FRANCISCO (TheStreet) -- The J.P. Morgan Healthcare Conference kicks off here tomorrow morning but we already have some intrigue, excitement and controversy.

Late Friday, Amarin (AMRN - Get Report) pulled out of the conference, citing reluctance to meet with investors ahead of a decision by FDA about reinstating the Special Protocol Assessment (SPA) for the Vascepa "Anchor" indication. Amarin expects to hear from the FDA no later than Wednesday. [I reprinted Amarin's statement below.]

Intercept Pharmaceuticals (ICPT - Get Report) and its red-hot fatty liver disease therapy obeticholic acid (OCA) will now take the Wednesday presentation slot vacated by Amarin. Oh boy, that's going to be one crowded room because the rocket ship which hurtled Intercept's market value into orbit last week on positive OCA study results may be hitting some turbulence.

On Friday night, The Wall Street Journal reported that patients treated with Intercept's OCA in the clinical trial experienced "lipid abnormalities" -- higher levels of "bad" LDL cholesterol and lowers levels of "good" HDL cholesterol -- compared to patients treated with placebo.

The disclosure about a potential safety risk tied to OCA came via a statement made by the National Institutes of Health, the sponsor of the clinical trial, which wanted to "give a broader context for the findings" of the trial, the Journal reported.

Watching how Intercept shares react to the Friday night OCA cholesterol disclosure when trading resumes early Monday morning will be the first big event of the J.P. Morgan conference.

Intercept shares closed Friday at $445.83, an unbelievable 516% rise from Wednesday's close of $72.39, all sparked by the announcement Thursday that a mid-stage study of OCA in patients with nonalcoholic steatohepatitis, or NASH, was stopped early due to "highly statistically significant improvement" in measures of liver health.

The market value of Intercept rose from $1.4 billion to $8.6 billion in two days of trading.

How the increase in cholesterol levels tied to OCA will affect the drug's ongoing clinical development or future commercial potential is unclear.

Intercept tried to downplay the significance of NIH's disclosure, telling the Journal Friday night that previously conducted and publicized studies of OCA also reported on the increases in cholesterol.

"It's very public that our drug, among other things, impacts lipid metabolism," Intercept CEO Mark Pruzanski told the Journal.

But among the fears expressed by some investors over the weekend is a longer development timeline for Intercept's OCA. Since increases in total cholesterol are a risk factor for heart disease, FDA, for example, might ask Intercept to conduct a large and time-consuming cardiovascular outcomes study before seeking the drug's approval.

The only thing for certain right now is that the incredible Intercept drama of the past few days will continue well into next week. Wednesday's presentation by Intercept executives at the J.P. Morgan conference -- particularly the Q&A breakout session -- is now a must-attend event.

Amarin's statement on pulling out of the J.P. Morgan conference:

As previously disclosed, the FDA has communicated its plan to respond to Amarin on the SPA reinstatement question not later than January 15, 2014 and the FDA has not informed Amarin of the date on which it will make its determination on the ANCHOR sNDA. Because Amarin and the FDA may engage in sensitive dialogue related to such ongoing matters during such time, Amarin does not currently plan to meet with investors or to have discussions with investors until after Amarin makes an appropriate public disclosure following significant updates from the FDA. Amarin is no longer scheduled to present at the J.P. Morgan annual healthcare investor conference.

-- Reported by Adam Feuerstein, flying 33,600 feet above Missouri, thanks to in-flight WiFi.

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Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.