Pharma and biotech stocks have been under a lot of pressure over the last few quarters with the NYSE ARCA Pharmaceutical Index and the Nasdaq Biotechnology index declining 4.1% and 11.7%, respectively, so far in 2016. Factors like the drug pricing controversy and a changing competitive scenario have been weighing on the sector. The drug pricing controversy gained tempo recently with lawmakers questioning Mylan’s pricing policy for its life-saving combination product, EpiPen.

However, quite a few pharma and biotech stocks had an impressive run in the month of September thanks to acquisition announcements, positive data readouts and FDA approvals.

Here is a look at 6 of the best-performing drug stocks of September.

Tobira Therapeutics, Inc. (TBRA -Free Report) and Vitae Pharmaceuticals, Inc. (VTAE - Free Report) saw their shares shooting up significantly on acquisition deals – both companies will be acquired by Allergan. Tobira, a Zacks Rank #3 (Hold) stock, is a clinical-stage biopharma company focused on the development and commercialization of treatments for non-alcoholic steatohepatitis (NASH) and other liver diseases. Allergan will be acquiring Tobira for an upfront payment of $28.35 per share, in cash, plus contingent value rights that may go up to $49.84 per share based on the successful achievement of development, regulatory and commercial milestones. The total value of the deal could reach $1.695 billion. Tobira’s shares shot up a whopping 720.9% on the deal announcement and were up 682.3% in the month of September.

TOBIRA THERAPTC Price and Consensus

TOBIRA THERAPTC Price and Consensus | TOBIRA THERAPTC Quote

Clinical-stage biotech stock, Vitae, which is also set to be acquired by Allergan, saw its shares jump 157.4% on the deal announcement. Vitae, which is working on developing first-in-class candidates with the potential to transform the treatment paradigm for patients with significant unmet medical needs, is initially pursuing indications like psoriasis, other autoimmune disorders, and atopic dermatitis.

The Zacks Rank #3 company’s shares were up 205.8% in the month of September. The acquisition, slated to close by year end, will see Allergan shelling out approximately $639 million.

VITAE PHARM INC Price and Consensus

VITAE PHARM INC Price and Consensus | VITAE PHARM INC Quote

Clinical-stage pharma company, Array BioPharma Inc.’s (ARRY - Free Report) shares gained 81.1% on positive data from a late-stage study (COLUMBUS) on an experimental combination treatment - encorafenib (a BRAF inhibitor) plus binimetinib (a MEK inhibitor) - for a certain type of skin cancer. Array and partner Pierre Fabre said that median progression free survival (PFS) in BRAF-mutant melanoma patients was 14.9 months for their experimental combination treatment compared to 7.3 months for Zelboraf (vemurafenib, BRAF inhibitor).

Results from the second part of the phase III study are expected in mid-17 with global regulatory submissions planned for 2017. Array’s shares were up 91.8% in September and touched a 52-week high as well.

ARRAY BIOPHARMA Price and Consensus

ARRAY BIOPHARMA Price and Consensus | ARRAY BIOPHARMA Quote

Cambridge, MA-based biopharma company Sarepta Therapeutics, Inc. (SRPT -Free Report) got a huge boost in September with the FDA approving the company’s first drug -- Exondys 51, for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation in the DMD gene that is amenable to exon 51 skipping. Exondys 51’s approval was a major milestone for the company which saw its shares soaring 131.2% in September. Exondys 51 is the first DMD treatment approved in the U.S. -- DMD affects about one in approximately every 3,500 – 5,000 males born worldwide.

SAREPTA THERAP Price and Consensus

SAREPTA THERAP Price and Consensus | SAREPTA THERAP Quote

Boulder, CO-based Clovis Oncology, Inc.’s (CLVS - Free Report) shares were up 52.8% in September. The biopharma company is focused on acquiring, developing and commercializing innovative cancer treatments in the U.S., Europe and other international markets. The company is currently seeking approval for rucaparib for a certain type of ovarian cancer. The FDA has granted priority review to the Zacks Rank #2 (Buy) stock with a response expected on Feb 23, 2017.

CLOVIS ONCOLOGY Price and Consensus

CLOVIS ONCOLOGY Price and Consensus | CLOVIS ONCOLOGY Quote

Aerie Pharmaceuticals, Inc. (AERI - Free Report) , a clinical-stage pharma company, presented positive 90-day data in September on its experimental eye disease treatment, Roclatan, from a late-stage study. The Zacks Rank #3 company’s shares were up 96.5% in September.

AERIE PHARMACT Price and Consensus

AERIE PHARMACT Price and Consensus | AERIE PHARMACT Quote