Annual report pursuant to Section 13 and 15(d)

Subsequent Events (Details Narrative)

Subsequent Events (Details Narrative)				1 Months Ended	12 Months Ended
Subsequent Events (Details Narrative)	Jan. 30, 2019 USD ($) $ / shares shares	Jan. 03, 2019 USD ($)	Jan. 01, 2019 shares	Apr. 30, 2014	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) shares	Feb. 26, 2019 ft²
Proceeds from issuance of common stock					$ 12,052,645	$ 78,891,699
Stock issuance cost					464,680	$ 2,969,837
Evergreen Provision [Member] \| 2014 Equity Incentive Plan [Member]
Increased number of shares of common stock available for issuance \| shares						2,500,000
Percentage of outstanding common shares				7.00%		7.00%
Kaken Pharmaceutical Co., Ltd. [Member]
Upfront payment, received from related party					$ 27,000,000
Subsequent Event [Member] \| New Premises [Member]
Area of land for office space \| ft²							30,023
Subsequent Event [Member] \| Total Premises [Member]
Area of land for office space \| ft²							62,756
Subsequent Event [Member] \| Public Offering [Member]
Number of common stock share sold \| shares	6,198,500
Purchase price of shares \| $ / shares	$ 6.50
Proceeds from issuance of common stock	$ 40,290,250
Stock issuance cost	$ 2,667,000
Subsequent Event [Member] \| Public Offering [Member] \| Underwriters' Option [Member]
Number of common stock share sold \| shares	808,500
Subsequent Event [Member] \| Collaboration and License Agreement [Member] \| First Quarter of 2019 [Member]
Upfront payment, received from related party		$ 27,000,000
Subsequent Event [Member] \| Evergreen Provision [Member] \| 2014 Equity Incentive Plan [Member]
Increases in number of shares of common stock available for issuance, minimum percentage of outstanding common stock			7.00%
Increased number of shares of common stock available for issuance \| shares			3,000,000
Percentage of outstanding common shares			7.00%
Total reserve under the plan \| shares			18,543,739
Shares available for future grants \| shares			80,722,414
Subsequent Event [Member] \| Kaken Pharmaceutical Co., Ltd. [Member] \| Collaboration and License Agreement [Member]
Upfront payment, received from related party		27,000,000
Consideration received on milestone payments		$ 173,000,000
Royalty term description		Ten (10) years after the first commercial sale of such Licensed Product for such Initial Indication in Japan. The Agreement may be terminated by either party for material breach, upon a party's insolvency or bankruptcy or upon a challenge by one party of any patents of the other party, and Kaken may terminate in specified situations, including for a safety concern or clinical failure, or at its convenience following the second anniversary of the first commercial sale of a Licensed Product in either of the Initial Indications in the Territory, with 180 days' notice.