Let's take a quick look at three stocks -- Vanda Pharmaceuticals (NASDAQ:VNDA), Prosensa Holding (NASDAQ: RNA), and Clovis Oncology (NASDAQ:CLVS) -- which could all make waves across the health care sector this Tuesday morning.

The European Medicines Agency accepts Vanda's MAA for Hetlioz
The European Medicines Agency (EMA) just accepted Vanda Pharmaceuticals' Marketing Authorization Application (MAA) for Hetlioz (tasimelteon), a treatment for non-24-hour sleep-wake disorder (non-24). Non-24 is a rare disorder which affects blind people who have trouble adjusting their sleep cycles to natural circadian rhythms. Vanda stated that as many as 95,000 people in the U.S. and 130,000 people in Europe suffer from non-24.

The FDA approved Hetlioz in January, and Vanda launched the drug in the U.S. on April 21, 2014. Analysts polled by Thomson Reuters expect the drug to achieve peak sales of $295 million by 2018.

Hetlioz is Vanda's second approved product. Its other marketed product is the schizophrenia drug Fanapt, which is commercialized in the U.S. and Canada by Novartis under a licensing agreement. Vanda reported revenues of $33.9 million in fiscal 2013, including $7.1 million in royalties from Fanapt. It finished last year with a net loss of $0.67 per share, or $20.3 million.

Prosensa surges after the FDA outlines an accelerated approval pathway for drisapersen
Meanwhile, shares of Prosensa Holdings are up modestly in pre-market trading this morning, after the FDA outlined an accelerated approval pathway for drisapersen, its experimental treatment for Duchenne Muscular Dystrophy (DMD), based on its existing trial data.

DMD is a rare and fatal genetic disease which causes muscular atrophy in approximately one out of 3,500 boys worldwide. The disease confines most patients to a wheelchair by age 12 and dramatically decreases life expectancy. There are no approved treatments for DMD. Two experimental drugs -- Prosensa's drisapersen and Sarepta's (NASDAQ:SRPT) eteplirsen -- are the most closely watched potential treatments for DMD.

The key takeaway from this morning's announcement is that the FDA now has enough faith in drisapersen to put it on an accelerated path toward a market approval. It's also a much needed vote of confidence for Prosensa, which has fallen out of favor after former partner GlaxoSmithKline ended their marketing partnership for drisapersen in January.

Based on the positive development with the FDA, Prosensa now plans to file an new drug application (NDA) for drisapersen later this year, committing to two confirmatory post-approval studies. The company has also expressed its intention for a filing in Europe as well. If approved, Kepler Capital Markets believes that Prosensa's drisapersen could generate peak sales of £500 million ($838 million), which is roughly the same as estimates for Sarepta's eteplirsen. Sarepta also plans to file an NDA for eteplirsen by the end of the year.

Clovis continues falling on hyperglycemia fears
Last but not least, Clovis Oncology is down 10% in pre-market trading this morning, due to fears that one of its two lead drug candidates, the lung cancer drug CO-1686, could be causing difficult-to-control hyperglycemia, with many patients on metformin and potentially a few on insulin.

Clovis CEO Pat Mahaffay noted in an interview on CNBC yesterday that some lung cancer patients in the ongoing phase I/II study of CO-1686 were now taking metformin to control high blood sugar levels caused by the experimental drug, and that a few patients had "briefly" gone on insulin when they had initially discovered the high blood sugar. However, Mahaffay reiterated that the drug does not cause diabetes.

Analysts at Mizuho Securities stated that the high blood sugar level found in some patients "appears manageable", and still believes that the drug is superior to its closest competitor, AstraZeneca's AZD9291, in terms of progression-free survival. Both Clovis and AstraZeneca's drugs target mutated, drug-resistant cancer cells which are resistant to traditional treatments like Roche's Tarceva and AstraZeneca/Teva's Iressa.

Clovis' two most advanced pipeline products are CO-1686 and rucaparib, a potential treatment for ovarian cancers with specific mutations. Analysts at Goldman Sachs believe that CO-1686 could generate peak sales of $1.9 billion if approved. Clovis does not have any marketed products.