(PCYC) is a clinical-stage biopharmaceutical company focused on discovering and developing small-molecule drugs for oncology and autoimmune diseases. PCYC's primary drug candidate is ibrutinib, the first in class of a new wave of oral agents ready to transform the treatment of white blood cell, or B-cell, malignancies.Almost all hematological cancers (involving the blood) arise from white blood cells including leukemia, lymphoma, and myeloma. Current treatments for blood cancers include Genentech's Rituxan, which is now owned by Biogen Idec (BIIB), and Celgene's (CELG) Revlimid. These drugs both achieved "blockbuster" status with sales in the billions of dollars. Analysts believe that PCYC's ibrutinib has the same or greater potential because it could surpass those drugs in terms of efficacy and safety. And it doesn't hurt that Johnson & Johnson (JNJ) is a partner. The R&D CatalystsPCYC shares have more than doubled this year, from $60 to over $140 in early October. In July, Pharmacyclics submitted its New Drug Application (NDA) for ibrutinib and by September began presenting positive data surrounding ibrutinib’s market potential and pipeline strategy including the development of the next-generation BTK inhibitor for autoimmune disease.They describe their drug's function as "a selective, irreversible inhibitor of Bruton’s tyrosine kinase (BTK), a critical signaling kinase in the B-cell receptor pathway for tumor cell survival and proliferation."Management indicated on September 12 at a conference that ibrutinib is on track for approval in late February, 2014 and they said the commercial force is built out and J&J is supplementing the 60+ PCYC U.S. sales force. You can see what happened to the stock in July and then again in September after a boat load of analysts woke up to the story...Late to the GameDuring the week of September 23, at least three investment banking firms initiated coverage of PCYC as follows...William Blair initiated with an Outperform rating and a $143 price target.Deutsche Bank initiated with a Buy rating and a $170 price target.JPMorgan initiated with an Overweight rating and a $142 price target.And on October 4th, Wells Fargo joined the party, initiating coverage with a $155-160 valuation range.On September 26, the day of the DB and JPM calls, PCYC shot up over $12 before noon (10%+). Some of these analysts even admitted they were late to the game. And I’ll admit that when I looked at this stock back in early August in a special Zacks Ultimate report "Picking Biotech Winners," I was skeptical about this as-yet-unprofitable company. Here's what I said on August 5..."PCYC is on a few radars after it popped up over 25% the week of July 8 on news that the company was submitting an NDA to the FDA for its oncology candidate, ibrutinib. But here's the caution with PCYC: many analysts believe it's already reached its full valuation at $100. In fact the Goldman Sachs covering analyst on the name only upped his target from $80 to $90 after this news. I’ll assume he knows something I don't." As far as I can tell, the Goldman analyst still hasn't revised his PT upwards.Early to the GameOne group of analysts who were early on the prospects for PCYC reside at Wedbush. Gregory R. Wade, David M. Nierengarten, and Christopher N. Marai -- all Ph.Ds -- have been covering PCYC for over a year. In March, when the stock was trading $86, they raised their 12-month price target to $165 from $110.And earlier this month, they put out a note about some competition from Gilead Sciences (GILD). The analysts wanted to address the success of a Phase III study of idelalisib (I), the PI-3 kinase inhibitor acquired with GILD's Calistoga acquisition. Their conclusion was that idelalisib should not be seen as a significant competitor to ibrutinib and they reiterated their Outperform rating on PCYC shares, also on their Best Ideas list.Of course it is one of their Best Ideas. They've had investors in PCYC since June of 2012 when it was trading $34 and they raised their price target to $55 from $40.The Definition of a Biotech BlockbusterPCYC has been either a Zacks Rank #1 (Strong Buy) or rank of #2 since August 3rd and I expect it to at least maintain a #3 Rank as the company gets closer to surviving all of its FDA gauntlets for ibrutinib. As more analysts get on this bandwagon, more refined sales estimates and drug launch costs will filter into a tighter dispersion of revenue and EPS estimates.According to the JPM analysts “ibrutinib has received 3 separate Breakthrough Designations from the FDA, highlighting the agency’s enthusiasm for the drug. This view is also mirrored by doctors, where excitement about the well-tolerated and highly effective new therapy seems universal.” When the FDA is enthusiastic, the analysts are ecstatic. Peak sales projections for ibrutinib are now in the range of $6 to $9 billion! Now that’s a blockbuster drug. Remember, many biotech analysts are either MDs or PhDs in the life sciences. And if they are not, they stay in contact with and read the research of those experts.When they understand a disease and its potential treatments enough to project its sales potential into the high single digits -- and the consensus is that high -- I’m on board. Here's an excerpt from the note that Deutsche analyst Robyn Karnauskas released on September 26...“Pharmacyclics is developing a best in class drug, ibrutinib, for the treatment of various hematological cancers. We believe the drug will transform the treatment of many blood cancers. Its unique in that it is oral, has very durable responses, & a good safety profile. We rate PCYC a BUY rating with a $170 TP because we believe the street is underestimating: (1) duration of treatment, (2) ability of JNJ to launch briskly, (3) doctor interest and speed of launch, (4) potential off-label use, and (5) the transformative nature of this drug across hematological cancers & potentially immunology.”The Waiting is the Hardest PartAs with all clinical-stage biopharma companies, investors are rewarded at various stages of clinical success. But sometimes the waiting periods and price volatility in between those milestones can be long and trying.That's why it is crucial to keep an eye on the analyst estimates for sales and (eventual) profits, and on the stock price. Finding a good entry point can mean the difference between having a "margin of safety" and nursing double-digit losses until the stock comes back. Aggressive biotech investors and traders should consider PCYC on dips below $120.Kevin Cook is a Senior Stock Strategist for Zacks where he runs the Follow The Money portfolio.