The end of March will be a nerve racking stretch for these three companies. Each one has nearly everything riding on a single product. Top management from Exact Sciences Corporation (EXAS -0.46%)Durata Therapeutics (NASDAQ: DRTX), and MannKind Corporation (MNKD 0.72%) are all facing perhaps the most important moments of their careers, beginning March 27.

Before making an approval decision, the FDA often assembles an advisory committee, or panel of independent experts, to consider the drug. According to the McKinsey Center for Government, between 2001 and 2010, the agency approved 88% of products recommended by its advisory committees, so the meeting will be an important hurdle for these companies, especially since they have a great deal riding on one product each. Expect some big movement in stock prices following these meetings.

Do it yourself
First up is Exact Sciences and its colorectal cancer screening test, Cologuard. Last spring the company released top-line data from a 10,000 patient pivotal trial. Results showed a 92% sensitivity for colorectal cancer, but only 42% for pre-cancerous polyps. This was a bit lower than expected, but clearly superior to existing non-invasive screens.

If approved, the screen should please insurers and government payers. The American Cancer Society estimates over 136,000 new cases of combined colon and rectal cancer, and about 50,000 deaths from the disease in 2014. Earlier detection results in far more effective, and less expensive, treatment. As you can imagine, patient compliance for regular screenings is lousy. Cologuard's self-administered sample kit isn't pleasant, but it's a step in the right direction.

New rule
Next up is Durata Therapeutics and its lead product dalbavancin. The FDA sort of moved the goal posts on the previous owner of this antibiotic, Pfizer when it changed a protocol and required an additional non-inferiority study. The requirement was not specific to dalbavancin, but Pfizer washed its hands of the antibiotic anyway. Sensing a low risk opportunity, Durata acquired the rights, then successfully completed the required trial.

Like the Cologuard test, payers have a lot to like about this novel antibiotic. Its advantage lies in its pharmacokinetic profile. A single infusion of dalbavancin remains at an effective level in the blood stream for about a week. This would allow earlier hospital discharges, free up hospital beds and staff, and save a bundle in the process. Given the accelerating growth of antibiotic resistant infections, I'll bet Pfizer wishes it never let this one go.

Deep breaths
April Fool's Day brings us to perhaps the most hotly anticipated advisory committee meeting of the year. MannKind Corporation will take its third swing at approval for its inhaled insulin device, Afrezza.

Unlike Pfizer's misadventure with Exubera, Mannkind argues Afrezza is more than just convenient. It insists it's a more effective treatment for both type 1 and 2 diabetes, and a pair of late stage studies suggests this might be true. In a trial with type 1 patients, Afrezza patients achieved lower fasting blood glucose levels, and a lower rate of total hypoglycemia. In a trial with type 2 patients, Afrezza was more effective at lowering blood sugar than metformin. 

The FDA's main complaint back in 2011 wasn't safety or efficacy of the insulin itself, but rather the next generation inhaler. There wasn't anything identified as wrong with it; the agency just wants to be absolutely certain that data from the old device is "comparable" to the new one.

There are plenty of important questions regarding Afrezza. I think the biggest concern is long-term safety. The company is in the middle of a 52-week study of patients with asthma or chronic obstructive pulmonary disease. The results aren't included in the NDA, but a year of monitoring 510 patients is an awfully big expense. It seems that MannKind has the same lingering concerns.