BEDMINSTER, NJ ( TheStreet) -- The commercial future of Amarin's ( AMRN) prescription fish-oil pill AMR101 may have been decided at a meeting between top company executives and officials from the U.S. Food and Drug Administration on June 22. The subject of the June 22 meeting between Amarin and FDA was "Orange Book Discussion," according to a calendar posted on the FDA's web site. Details of the meeting and its outcome aren't publicly known and Amarin won't comment. But based on the subject and the people who participated, the marketing exclusivity of AMR101 -- how many years Amarin will get to sell the fish-oil pill before generic drug makers can file a challenge to enter the market -- was the likely topic. Amarin shares fell 6% to $14.40 on Tuesday and were down almost 10% intraday as awareness and worries about this June 22 meeting spread around Wall Street. The FDA's decision over whether or not to grant AMR101 so-called New Chemical Entity (NCE) status -- and the five years of market exclusivity that goes with it -- is almost as important to Amarin as getting the drug approved on July 26. If FDA grants NCE status to AMR101, Amarin will have five years of market exclusivity, regardless of the patent situation. Recent patent grants and allowances are likely to extend protection through 2030. With NCE status for AMR101, generic drug makers are also prohibited from submitting so-called paragraph 4 filings to FDA (challenges to existing drug patents) for four years. Without NCE status, AMR101's market exclusivity shrinks to three years and generic drug makers can file paragraph 4 challenges immediately after approval. These extra two years of market exclusivity and restrictions on paragraph 4 filings are important in determining the long-term profitability of AMR101. Without the maximum market exclusivity, AMR101's commercial value may be diminished -- the drug might be incapable of generating the billion dollars in sales or more that investors have come to expect because cheaper, generic versions could enter the market sooner. Large pharmaceutical companies possibly interested in partnering with or even acquiring Amarin may stay away. FDA is expected to issue an approval decision on AMR101 on or before July 26. The decision on the drug's NCE status should be announced at the same time. If FDA approves AMR101 but doesn't grant the drug NCE status, Amarin's stock price could fall on fears that generic drug makers will immediately file paragraph 4 challenges in an effort to invalidate AMR101's patents.