Three Months Ended

March 31, 2019

June 30, 2019

September 30, 2019

December 31, 2019

Revenue

$

454

$

462

$

558

508

Operating expenses:

Research and development

12,562

15,475

15,931

14,277

General and administrative

4,865

5,195

5,016

6,402

Total operating expenses

17,427

20,670

20,947

20,679

Loss from operations

(16,973

)

(20,208

)

(20,389

)

(20,171

)

Other income, net

512

753

596

442

Net loss applicable to common stockholders

$

(16,461

)

$

(19,455

)

$

(19,793

)

(19,729

)

Net loss per share applicable to common stockholders - basic and diluted

$

(0.49

)

$

(0.47

)

$

(0.47

)

(0.46

)

Weighted-average number of common shares used in net loss per share applicable to common stockholders - basic and diluted

33,766,333

41,673,275

42,439,338

42,885,208

Three Months Ended

March 31, 2018

June 30, 2018

September 30, 2018

December 31, 2018

Revenue

$

370

$

375

$

412

$

893

Operating expenses:

Research and development

11,116

11,082

12,856

15,128

General and administrative

4,075

3,841

3,876

4,372

Total operating expenses

15,191

14,923

16,732

19,500

Loss from operations

(14,821

)

(14,548

)

(16,320

)

(18,607

)

Other income, net

358

501

583

575

Net loss applicable to common stockholders

$

(14,463

)

$

(14,047

)

$

(15,737

)

$

(18,032

)

Net loss per share applicable to common stockholders - basic and diluted

$

(0.48

)

$

(0.43

)

$

(0.47

)

$

(0.54

)

Weighted-average number of common shares used in net loss per share applicable to common stockholders - basic and diluted

30,335,164

32,892,712

33,653,479

33,694,756