Exhibit 99.1

•

ABI-H0731: Assembly’s lead core inhibitor candidate

o

The Phase 2 open-label extension study (Study 211) is ongoing with subjects reaching 12-18 months of combination treatment with ABI-H0731 and standard-of-care nucleos(t)ide analogue reverse transcriptase inhibitor (NrtI) therapy.

o

Assembly has determined the stopping criteria by which it will begin transitioning patients off therapy, and these criteria have been discussed with its lead investigators and reviewed and agreed upon by the U.S. Food and Drug Administration (FDA).

o

Assembly has submitted an End of Phase 2 meeting request and briefing document for review with China regulatory authorities to plan for the initiation of studies aimed at supporting the registration of ABI-H0731 with NrtI for chronic suppressive therapy in China.

•

ABI-H2158, Assembly’s second-generation, more potent core inhibitor candidate, has completed the dose-ranging Phase 1b clinical trial and the Company has selected the 300 mg daily dose of ABI-H2158 to advance into Phase 2 development. The Company is preparing to initiate a multi-center, randomized, placebo-controlled Phase 2 trial evaluating ABI-H2158 with entecavir versus placebo with entecavir in approximately 80 treatment-naïve, HBeAg positive patients with chronic HBV infection.

•

ABI-H3733, Assembly’s third core inhibitor candidate, has continued to advance in development. A Phase 1 trial is now open for enrollment and will evaluate safety, tolerability, and pharmacokinetics following single ascending dose and multiple ascending dose administrations of ABI-H3733 in healthy subjects.

•

Additional information on the above, and Assembly’s other recent progress with its HBV core inhibitor portfolio, will be shared today at 1:30 pm PT during a conference call and simultaneous webcast (connection information provided below). The slides presented during the webcast will be available shortly after the call on Assembly’s website.  

•

In March 2020, research into the turnover and presumed half-life of covalently closed circular DNA (cccDNA) pools, which play a pivotal role in the establishment and persistence of HBV infection, was first published online in Hepatology, the journal of the American Association for the Study of Liver Diseases.  

•

Preclinical data on Assembly Biosciences’ Microbiome program in ulcerative colitis (UC) were presented in a poster during Digestive Disease Week’s 2020 Virtual Meeting. A copy of the poster is available on Assembly Biosciences’ website. In addition, the abstract is scheduled for publication in the May online supplements to the journals Gastroenterology and GIE: Gastrointestinal Endoscopy.

•

In March 2020, Jason Okazaki joined as Chief Legal and Business Officer.

•

In April 2020, Carl Henrik Enell joined as Senior Vice President, Corporate Development.

•

ABI-H0731

o

Presentation of additional interim analyses from Study 211 at the European Association for the Study of the Liver’s (EASL) Digital International Liver Congress, rescheduled to August 27-29, 2020; abstracts were accepted as an oral presentation (HBeAg negative patients) and as a late-breaking poster (HBeAg positive patients).

o

Plan to begin taking patients off of combination therapy later this year, to then monitor for sustained virologic response.

•

ABI-H2158

o

Plan to initiate a Phase 2 clinical trial in the second quarter of 2020.

o

Presentation of Phase 1b clinical data on multiple dose cohorts accepted for inclusion at EASL as a late-breaking poster.

•

ABI-H3733

o

Continuation of ongoing Phase 1 clinical trial.

•

Proprietary In-House HBV DNA and pgRNA Assays

o

Poster presentation of Assembly’s highly sensitive assays at EASL.

•

ABI-M201

o

Continuation of the ongoing multi-center randomized, placebo-controlled Phase 1b trial in patients with mildly to moderately active UC.

•

Microbiome Platform

o

Poster presentation of preclinical data from Assembly’s microbiome immuno-oncology program at the American Association for Cancer Research Virtual Annual Meeting II, June 22-24, 2020.

o

Expanded utilization of Assembly’s rational function-based microbial discovery platform and in-house high-quality manufacturing expertise to advance new proprietary live biotherapeutic consortium candidates for oncology and other disease indications.

•

Cash, cash equivalents and marketable securities were $249.1 million as of March 31, 2020, compared to $274.0 million as of December 31, 2019. This cash position is projected to fund operations into 2022.

•

Revenues from collaborative research were $4.1 million for the three months ended March 31, 2020 compared to $3.9 million for the same period in 2019.

•

Research and development expenses were $23.0 million for the three months ended March 31, 2020, compared to $22.7 million for the same period in 2019. The increase was primarily due to an increase of $0.4 million in gross research and development expenses related to the Microbiome programs and a decrease of $0.1 million in research and development expenses related to the HBV programs. Research and development expenses include non-cash stock-based compensation expenses of $1.9 million for the three months ended March 31, 2020 and $2.7 million for the same period in 2019.

•

General and administrative expenses were $8.7 million for the three months ended March 31, 2020 compared to $9.5 million for the same period in 2019. General and administrative expenses include non-cash stock-based compensation expenses of $3.0 million for the three months ended March 31, 2020 and $3.8 million for the same period in 2019.

•

Net loss attributable to common stockholders was $26.7 million, or $0.76 per basic and diluted share, for the three months ended March 31, 2020 compared to $27.1 million, or $1.05 per basic and diluted share, for the same period in 2019.

March 31,

December 31,

2020

2019

(Unaudited)

ASSETS

Current assets

Cash and cash equivalents

$

42,326

$

46,732

Marketable securities

206,803

227,311

Accounts receivable from collaboration

3,055

3,374

Prepaid expenses and other current assets

4,568

5,363

Total current assets

256,752

282,780

Property and equipment, net

1,780

1,830

Operating lease right-of-use assets

11,479

11,975

Other assets

1,661

1,684

Indefinite-lived intangible asset

29,000

29,000

Goodwill

12,638

12,638

Total assets

$

313,310

$

339,907

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities

Accounts payable

$

2,104

$

1,731

Accrued clinical expenses

4,633

4,826

Other accrued expenses

4,430

8,286

Deferred revenue - short-term

6,715

6,411

Operating lease liabilities - short-term

3,264

3,186

Total current liabilities

21,146

24,440

Deferred tax liabilities

2,531

2,531

Deferred revenue - long-term

29,326

30,637

Operating lease liabilities - long-term

8,539

9,082

Total liabilities

61,542

66,690

Commitments and contingencies

Stockholders' equity

Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued or outstanding

—

—

Common stock, $0.001 par value; 100,000,000 shares authorized as of March 31, 2020 and December 31, 2019; 32,624,725 and 32,558,307 shares issued and outstanding as of March 31, 2020 and December 31, 2019, respectively

32

32

Additional paid-in capital

717,898

712,807

Accumulated other comprehensive loss

(86

)

(201

)

Accumulated deficit

(466,076

)

(439,421

)

Total stockholders' equity

251,768

273,217

Total liabilities and stockholders' equity

$

313,310

$

339,907

Three Months Ended

March 31,

2020

2019

Collaboration revenue

$

4,081

$

3,885

Operating expenses:

Research and development

23,046

22,704

General and administrative

8,729

9,517

Total operating expenses

31,775

32,221

Loss from operations

(27,694

)

(28,336

)

Other income (expenses)

Interest and other income, net

1,039

1,277

Total other income

1,039

1,277

Loss before income taxes

(26,655

)

(27,059

)

Income tax benefit

-

7

Net loss

$

(26,655

)

$

(27,052

)

Other comprehensive (loss) income

Unrealized gain on marketable securities, net of tax

115

108

Comprehensive loss

$

(26,540

)

$

(26,944

)

Net loss per share, basic and diluted

$

(0.76

)

$

(1.05

)

Weighted average common shares outstanding, basic and diluted

35,079,756

25,668,798