Let's take a look at today's top stories in biotech and health care. Keep an eye out for AbbVie (NYSE:ABBV), Bind Therapeutics (NASDAQ:BIND)MannKind Corp. (NASDAQ:56400P706) and Shire (NASDAQ:SHPG)

AbbVie still pursuing Shire 
Despite three rejections so far, AbbVie is reportedly still attempting to convince Shire and its major shareholders that a buyout is in their best interest. Per sources familiar with the dealings, AbbVie's CEO Richard Gonzalez traveled to London recently to hold discreet meetings with Shire's largest shareholders.  

Shire's management has repeatedly stated that the reported tender offer of $46 billion does not properly value the company in light of its growth prospects, especially those in the orphan drug arena.

What we are hearing today is that Gonzalez's case centers around AbbVie doing a better job at commercializing those assets than Shire could on their own. While that remains to be seen, Shire believes its orphan drug portfolio should see sales of $10 billion by 2020. As such, they don't appear to be keen on entertaining the current offer, regardless of any potential commercial synergies a merger would create. Put simply, I don't think AbbVie's renewed efforts at a buyout will amount to anything unless they are willing to significantly up the tender offer. Shire's shares are down slightly in premarket following this news. 

Bind ends cancer partnership with Amgen, shares crater
Small-cap biopharma Bind Therapeutics announced yesterday that it has ended its cancer partnership with Amgen, causing shares to fall by over 15% in after hours trading. Bind's shares are down over 10% in premarket trading. The partnership was terminated due to "unsatisfactory results" from clinical work using Bind's nanomedicine platform combined with an undisclosed proprietary cancer compound developed by Amgen. 

MannKind falling after FDA approval
Shares of MannKind Corp. have now dropped nearly 7% since announcing the approval of its inhaled insulin product Afrezza by the Food and Drug Administration last Friday. On Monday, shares jumped almost 10%, but have since plummeted, as investors begin to take profits following the recent run-up heading into the approval. 

Today's pre-holiday action could thus be critical for this mid-cap biopharma. Simply put, we might see investors continue to lock in profits before the long July 4 weekend. That being said, MannKind shares are presently up 0.2% in premarket trading on moderately heavy volume.  

Looking head, MannKind's next catalyst is likely to be a partnership. As I've mentioned before, the details of the widely anticipated commercialization partnership should ultimately dictate how this stock performs over the long term. And right now, we don't have much insight into how this will play out in the coming weeks. As such, you may want to stick to the sidelines until this issue has been resolved.