Certain statements contained in this presentation regarding matters that are not historical facts, are forward-looking statements within the meaning of Section 21E of the Securities and Exchange Act of 1934, as amended,

Forte biosciences TOPICAL live

biotherapeutic for the treatment of Inflammatory skin disease Forte biosciences and Tocagen Merger February 2020 Exhibit 99.1

Certain statements contained in this

presentation regarding matters that are not historical facts, are forward-looking statements within the meaning of Section 21E of the Securities and Exchange Act of 1934, as amended, and the Private Securities Litigation Act of 1995, known as the

PSLRA. These include statements regarding management's intention, plans, beliefs, expectations or forecasts for the future, and, therefore, you are cautioned not to place undue reliance on them. No forward-looking statement can be guaranteed,

and actual results may differ materially from those projected. Tocagen and Forte undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent

required by law. We use words such as "anticipates," "believes," "plans," "expects," "projects," "intends," "may," "will," "should,"

"could," "estimates," "predicts," "potential," "continue," "guidance," and similar expressions to identify these forward-looking statements that are intended to be covered by

the safe-harbor provisions of the PSLRA. Such forward-looking statements are based on our expectations and involve risks and uncertainties; consequently, actual results may differ materially from those expressed or implied in the statements due to a

number of factors, including, but not limited to, risks relation to the completion of the transaction, including the need for Tocagen stockholder approval and the satisfaction of closing conditions; the anticipated financing to be completed

concurrently with the closing of the transaction; the cash balance of the company following the closing the transaction and the financing, and the expectation with respect thereto; the business and prospects of the company following the transaction;

and the ability of Tocagen to remain listed on the Nasdaq Capital Market. Risks and uncertainties related to Forte that may cause actual results to differ materially from those expressed or implied in any forward-looking statement include, but are

not limited to: Forte's plans to develop and potentially commercialize its product candidates, including FB-401; the timing of initiation of Forte's planned clinical trials; the timing of the availability of data from Forte's

clinical trials; the timing of any planned investigational new drug application or new drug application; Forte's plans to research, develop and commercialize its current and future product candidates; Forte's ability to successfully

enter into collaborations, and to fulfill its obligations under any such collaboration agreements; the clinical utility, potential benefits and market acceptance of Forte's product candidates; Forte's commercialization, marketing and

manufacturing capabilities and strategy; Forte's ability to identify additional products or product candidates with significant commercial potential; developments and projections relating to Forte's competitors and our its industry; the

impact of government laws and regulations; Forte's ability to protect its intellectual property position; and Forte's estimates regarding future revenue, expenses, capital requirements and need for additional financing following the

proposed transaction. These risks, as well as other risks associated with the transaction, will be fully discussed in the proxy statement/prospectus that will be included in the registration statement that will be filed by Tocagen with the SEC in

connection with the proposed transaction. Additional risks and uncertainties are identified and discussed in the "Risk Factors" section of Tocagen's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and other documents

filed from time to time with the SEC. Forward-looking statements included in this presentation are based on information available to Tocagen and Forte as of the date of this presentation. Neither Tocagen nor Forte undertakes any obligation to such

forward-looking statements to reflect events or circumstances after the date of this presentation. Cautionary note regarding forward-looking statements

Additional information and where you

can find it Additional Information About the Proposed Transaction and Where to Find it This communication is being made in respect of a proposed transaction involving Forte Biosciences, Inc. and Tocagen, Inc. Tocagen intends to file a registration

statement on Form S-4 with the U.S. Securities and Exchange Commission (the "SEC"), which will contain a proxy statement/prospectus and other relevant materials, and plans to file with the SEC other documents regarding the proposed

transaction. The final proxy statement/prospectus will be sent to the stockholders of Tocagen in connection with the Tocagen special meeting of stockholders to be held to vote on matters relating to the proposed transaction. The proxy

statement/prospectus will contain information about Tocagen, Forte, the proposed transaction, and related matters. STOCKHOLDERS ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS (INCLUDING ANY AMENDMENTS OR SUPPLEMENTS THERETO) AND OTHER DOCUMENTS

FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE, AS THEY WILL CONTAIN IMPORTANT INFORMATION THAT STOCKHOLDERS OF TOCAGEN SHOULD CONSIDER BEFORE MAKING A DECISION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. In

addition to receiving the proxy statement/prospectus and proxy card by mail, Tocagen stockholders will also be able to obtain the proxy statement/prospectus, as well as other fillings containing information about Tocagen, without charge, from the

SEC's website (http://www.sec.gov) or, without charge, on Tocagen's website at https://tocagen.com, by contacting Mark Foletta by phone at (858) 412-8499, or by electronic mail at mfoletta@tocagen.com. No Offer or Solicitation This

communication is not intended to and does not constitute an offer to sell or the solicitation of an offer to subscribe for or buy or an invitation to purchase or subscribe for any securities or the solicitation of any vote or approval in any

jurisdiction in connection with the proposed transaction or otherwise, nor shall there be any sale. Issuance or transfer of securities in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a

prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended. Participants in Solicitation Tocagen and its executive officers and directors may be deemed to be participants in the solicitation of proxies from

Tocagen' stockholders with respect to the matters relating to the proposed transaction. Forte may also be deemed a participant in such solicitation. Information regarding Tocagen' executive officers and directors is available in

Tocagen's proxy statement on Schedule 14A for its 2018 Annual Meeting of stockholders, filed with the SEC on April 19, 2019. Information regarding any interest that Tocagen, Forte or any of the executive officers or directors of Tocagen or

Forte may have in the transaction with Forte will be set forth in the proxy statement/prospectus that Tocagen intends to file with the SEC in connection with its stockholder vote on matters relating to the proposed transaction. Tocagen stockholders

will be able to obtain this information by reading the proxy statement/prospectus when it becomes available.

Forte Biosciences - Tocagen

Merger Forte Biosciences and Tocagen agreed to merge on February 19, 2020 in an all-stock transaction and is expected to trade on Nasdaq under new symbol FBRX The transaction is expected to close in 2Q20 Forte Biosciences investors will provide a

concurrent financing of $14 million Forte Biosciences holders will own approximately 74.5% and Tocagen holders will own 25.5% of the combined company, subject to certain adjustments The total cash balance of the combined company is expected to be

approximately $25 million Post-Merger Board of Directors to include 8 representations: 6 designated by Forte Biosciences and 2 designated from Tocagen The transaction has been approved by the Board of Directors of both companies and is subject to

stockholder approval of Tocagen holders +

Summary OF Forte Biosciences: FB-401

- POTENTIAL first-in-class topical live biotherapeutic for the treatment of inflammatory Skin disease Late-stage CLINICAL Asset Phase 2a trial in atopic dermatitis completed including pediatrics 3 years and older, demonstrating safety and

efficacy of FB-401. Randomized Phase 2 initiation in adults and pediatrics 2 years and older expected in mid-2020 in atopic dermatitis (AD) with expected data readout in mid-2021 10-20% of children in industrialized countries develop atopic

dermatitis (AD) In the U.S. , AD affects 17 million people (over 50% are children) Significant unmet need for safe and effective AD therapy for pediatrics Large market with unmet need Clinical data demonstrates safety and activity of FB-401 Phase 2a

study, including pediatrics, demonstrates clean safety profile and significant reduction in atopic dermatitis disease and pruritus, as well as control of S. aureus while tapering/eliminating steroid use Potential First-in-class topical live

biotherapeutic Exclusive license to NIH-owned patent families as well as Forte owned IP. Coverage includes composition and method of use patents Patent coverage through at least 2037 (4 U.S. patents issued) Intellectual Property Series A financing

of $10 million in 2019 from ArrowMark Partners; concurrent financing of $14 million from experienced life science investors including Alger, BVF Partners LP and OrbiMed Cash runway expected to be sufficient through Phase 2 data readout in mid-2021

Management team with significant drug development, innovation and corporate strategy experience Financing / Management

FORTE BIOSCIENCES: Overview of FB-401

FB-401 drug product consists of 3 therapeutic bacterial strains of commensal gram negative R. mucosa specifically selected based on screening for impact on inflammatory skin disease parameters Topical application of the specifically selected

therapeutic bacterial strains of R. mucosa drug product: Drives immune pathways that are defective Suppresses Staphylococcus aureus growth Improves skin barrier function Clinical data demonstrates safety and activity of FB-401 live biotherapeutic

therapy in both adults and pediatric Phase 2a study, including pediatrics, demonstrates clean safety profile and significant reduction in atopic dermatitis disease and pruritus, as well as control of S. aureus while tapering/eliminating steroid use

Randomized Phase 2 trial initiation expected in mid-2020

EXPERIENCED management and advisory

Teams Paul Wagner, Ph.D. - CEO Forte Biosciences team has extensive experience in microbial manufacturing, quality, regulatory and clinical development in dermatology Dan Burge, MD - Head of Clinical Development Eric Emery - Head

of Downstream Manufacturing Hank Talbot, Ph.D. - Head of Process Development and Quality Scientific Advisory Board (SAB) Prof. Amy Paller, MD - Chair, Department of Dermatology Northwestern University Feinberg School

of Medicine Prof. Lawrence Eichenfield, MD - Chief of Pediatric and Adolescent Dermatology at Rady Children's Hospital-San Diego, Editor in Chief of Pediatric Dermatology Prof. Eric Simpson, MD -Professor of

Dermatology, Oregon Health & Science University, Portland Dr. Patricia Walker, MD, Ph.D. - Former CMO of Allergan Medical and Dermatology TA Head

Atopic dermatitis Atopic dermatitis

(AD) is characterized by itching, a scaly rash, dry skin, and cutaneous sensitization to allergens. The underlying pathology of AD consists of a triad of defective skin barrier function, susceptibility to Staphylococcus aureus skin infection, and

immune imbalance (overactive adaptive immunity in lieu of innate immunity) 10-20% of children in industrialized countries develop atopic dermatitis with increasing incidence. 80% of children with severe disease continue to have lifelong

exacerbations There is currently no cure for AD In the US, the prevalence of atopic dermatitis is approximately 17 million More than half of that prevalence is pediatric (<17 years old) Treatment options for pediatrics are very limited FDA

Pediatric Subcommittee October 29-30, 2003 American Academy of Dermatology Affects flexural areas of neck, elbows, knees, wrists, and ankles Lichenified, erythematous plaques behind the knees Erythematous, excoriated papules with overlying crust in

the antecubital fossa Erythematous ill-defined patches with overlying scale and erosions on her cheeks

SKIN MICROBIOME Dreno et al, European

Academy of Dermatology and Venerology 2016, 30, 2038-2047 Kong HH et al. Genome research. 2012;22(5):850-859 The skin is a complex barrier organ characterized by symbiotic relationship between microbial communities and host tissue via complex

signals provided by the innate and the adaptive immune systems Exposure to various endogenous and exogenous factors impact the system balance potentially leading to inflammatory skin conditions comprising infections, allergies or autoimmune diseases

Researchers in microbiology and dermatology identified and characterized the microorganisms present on the skin, to evaluate the bacterial diversity and their relative abundance and to understand how microbial diversity may contribute to skin health

and dermatological conditions Recent work has revealed that the skin microbiome is significantly different between healthy controls and patients with AD and that symptoms are associated with a loss of commensal diversity

SKIN MICROBIOME differences in

atopic dermatitis Myles IA, Williams KW, Reckhow JD, et al. JCI Insight. 2016;1(10) Kong HH et al. Genome research. 2012;22(5):850-859 Genetic-based microbiome identification revealed significant differences in the Gram-negative skin biome between

atopic dermatitis (AD) patients and healthy controls (HV) NIH (Myles et. al.) identified substantial differences in the gram-negative microbiome present on the skin of AD patients and healthy volunteers The predominant species of skin commensal

Gram negative bacteria (CGN) in HV found to be Roseomonas mucosa Over 50% of AD patients did not have any culturable Gram-negative flora, consistent with DNA-based analysis

Phase 2A First HUMAN study of

FB-401 - cutaneous live biotherapeutic for the treatment of atopic dermatitis Drug product: FB-401 (3 specifically selected therapeutic R. mucosa strains) lyophilized and reconstituted with sterile water in single-use, self-administered spray

Design: Phase 1/2a enrolled 2 cohorts: Initial cohort enrolled 10 adult atopic dermatitis patients 18 years and older Following positive safety assessment from cohort I, the second cohort of 20 pediatric patients was enrolled Primary Objective: To

evaluate the safety and activity of R mucosa as a live biotherapeutic for treatment of AD Secondary Objective: To evaluate the effect of R mucosa live biotherapy on quality of life of participants with AD Exploratory Objectives Measure trans

epidermal water loss (TEWL) Characterize changes to total and specific IgE Evaluate potential changes to pre-diagnosed asthma and/or food allergies Evaluate incidence of S aureus infections that require treatment Persistence of R mucosa colonization

Cohort 1 completed treatment of 10

adults with AD Ten adult AD patients ages 18 years and older were treated in 2-week intervals with 103, 104, and then 105 CFU of R mucosa twice per week (BIW) for a total of 6 weeks

Statistically significant,

Dose-dependent improvements observed in adult cohort of PHASE 1/2a Study (A) Intensity of AD disease was measured in a blinded manner using SCORAD measures of dryness, redness, lichenification, excoriation, crusting and edema (0-3 scale for each

measure) (B) Subjective pruritus reported by the patient on 0-10 scale (C) Antecubital-specific SCORAD (blinded) assessed antecubital region by summing local intensity and pruritic scores Only treated areas responded. No AD lesions that were

untreated resolved over the course of the study Results from Cohort 1 indicate that six patients responded (60%) with mean improvement of 85%, one patient reported partial response with 44% improvement and three were non responders with 9% mean

improvement * p<0.05 ** p<0.01 Myles et al, JCI Insight, 2018;3(9):e120608

Cohort 2: FB-401 Treatment of 20

Children with AD 20 pediatric/adolescent patients with active AD: First 5, ages 7-17 Remainder, ages 3-17 Baseline SCORAD >10 Design: Treat AD-involved skin with FB-401 103 CFU BIW for 4 weeks 104 CFU BIW for 4 weeks 105 CFU BIW for 4 weeks 105

CFU QOD for 4 weeks Efficacy assessments at baseline and Q4W SCORAD, pruritus, EASI (%, -50,-75,-90) TEWL, FDLQI, CDLQI Microbiome assessment Adverse events throughout and at F/U Baseline Week 4 Week 8 Week 12 Week 16 Pediatric Cohort Treatment

Data from First 5 pediatric

patients Shows Activity Across multiple parameters SCORAD score statistically significantly improved (A,B) 4/5 show more than 50% improvement and strong trend towards improvement in 5th patient Pruritus shows statistically significant improvement

(C) Both SCORAD and pruritus improvements achieved while steroid use tapered from an average of 20 applications (D) * p<0.05 ** p<0.01 Myles et al, JCI Insight, 2018;3(9):e120608

treatment with FB-401 demonstrates

significant improvement Myles et al, JCI Insight, 2018;3(9):e120608

Planned FB-401 Randomized Phase 2

Study CONFIDENTIAL Randomized, placebo-controlled, multi-center study Includes children (2 years and older), adolescents and adults with mild to moderate atopic dermatitis Approximately 124 subjects randomized 1:1 to receive FB-401 or placebo for 16

weeks Endpoints include Eczema Area and Severity Index (EASI), Investigator Global Assessment (IGA), pruritus

Intellectual property overview

Exclusive license to NIH-owned patent family focused on treatment of AD with a consortia of gram negative bacteria from healthy donors Patent coverage through at least 2037 4 US patents issued Entered in 10 Ex-US jurisdictions Europe, China, Canada,

Japan, South Korea, Australia, Singapore, Mexico, Israel, and Hong Kong Company-owned IP directed to compositions for treatment of skin conditions associated with dysbiosis Broadly covers use of gram negative bacteria for treatment of atopic