BOSTON (TheStreet) -- Friday means another Biotech Stock Mailbag. 

Nick H. emails: 

"I hope you are well and I appreciate the solid work you do. I have a question concerning Celgene (CELG - Get Report) that I hope you might be able to answer in one of your Biotech Stock Mailbags.

Almost one year ago was the Markman hearing related to the Revlimid patent challenge by NatCo/Actavis (ACT). At the time the patent challenge was seemingly a large overhang on the stock. While my understanding was that most thought the Markman hearing was favorable to Celgene, have there been any updates since? If not, when can we expect a conclusion or upcoming catalyst related to the patent challenge? I just find it odd that it was such a HUGE deal a year ago and now is never really mentioned."

Thanks, Nick. Investors still care about the Revlimid patent litigation between Celgene and Natco/Actavis, but it's no longer a pressing issue because an outcome in the case is far off.

The Markman hearings and subsequent rulings of last year favored Celgene, although Natco/Actavis scored enough points to keep the case moving forward. From what I understand, both sides are in the discovery process right now, which has no set end date. Celgene has told investors that a trial could start in the second half of the year. The company believes it has a strong case and expects to win.

My sense is investors would rather Celgene and Natco/Actavis settle before a trial.

Kevin writes:

"Hello Adam, I just wanted to say thanks for all that you do. I look forward to all your articles. I was hoping that you would do a little write up on the upcoming conferences and the top drugs and companies presenting at these conferences. You did that a few times last year and they were very helpful. Thanks."

Thank you, Kevin. The pace of medical conferences ramps up in the spring, so your question is well timed. Here's a calendar (probably incomplete) but enough to get your investment research started:

Society for Reproductive Investigation (SRI), March 25-28: OvaScience (OVAS) will be presenting the the first-ever data on success rates for its AUGMENT fertility treatment.

American Academy of Neurology (AAN), April 18-25: Look for more/updated data on Biogen Idec's (BIIB - Get Report) nerve repair drug candidate anti-LINGO-1.

American Association for Cancer Research (AACR), April 18-22: This meeting is largely devoted to early-stage cancer drug research. Cancer immunotherapy, particularly CAR-T therapies, remain red hot. So watch Juno Therapeutics (JUNO), Kite Therapeutics (KITE), Novartis (NVS - Get Report) and Bellicum (BLCM - Get Report). Merck (MRK - Get Report) will also present new data on its PD-1 checkpoint inhibitor Keytruda in lung cancer and mesothelioma.

European Association for the Study of the Liver (EASL) meeting, April 22-26: Hepatitis C data from Regulus Therapeutics (RGLS - Get Report), Merck and Gilead Sciences (GILD - Get Report). EASL is an important meeting for all hepatitis C drug stocks, although less so these days given all the new drugs on the market. More recently, Wall Street's focus at EASL has shifted to hepatitis B drugs.

Digestive Disease Week (DDW), May 17-19: Look for additional data on Celgene's mongersen in Crohn's disease, also Receptos (RCPT) and its lead pipeline product RPC1063 in ulcerative colitis.

American Society of Clinical Oncology (ASCO), May 29 - June 2. Cancer, cancer and more cancer. All cancer stocks.

Yes, CTI Biotherapeutics (CTIC - Get Report) is the first biotech company to break the Feuerstein-Ratain Rule, but with an asterisk.

The scenario I wrote about in January came true. CTI announced positive results from the pacritinib “PERSIST-1” study in myelofibrosis on March 9. Four months back from that date, November 9, CTI’s market value was around $350 million.

The Feuerstein-Ratain Rule says cancer drug phase III studies fail with 100% certainty when the company sponsoring the study has a market cap of $300 million or less, measured four months prior to the announcement of study results.

Taking into account inflated biotech valuations of the past two years, CTI's $350 million market cap predicted failure for the pacritinib PERSIST-1 study. But the study was a success. Therefore, the Feuerstein-Ratain Rule was broken for the first time. I predicted this would happen in January, and I was right.

Now, about that asterisk.

The Feuerstein-Ratain Rule assumes investors do a good and early job vetting the potential of a cancer drug. The market cap of the company developing the drug is a proxy for that potential. Highly effective drugs translate into large market caps long before study results are known, and vice versa.

The CTI case is different -- hence the asterisk -- because its de minimus market cap heading into the pacritinib study results was due to investor distrust (or outright disdain) for management. It had little to do with the pacritinib's chance of succeeding in in the PERSIST-1 study.

As I wrote in January, a lot of investors believe pacritinib is a real myelofibrosis drug (how good relative to competition is debatable), but they weren't willing to buy CTI stock for other reasons.

The questionable way in which CTI first refused to provide detailed data from PERSIST-1 but then dropped the data inside its 10-K a few days later was another reminder that CTI is a difficult company to trust.

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.