Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 13, 2022




(Exact name of registrant as specified in its charter)







(State or other jurisdiction
of incorporation)

(Commission File Number)

(IRS Employer
Identification No.)






395 Oyster Point Blvd., Suite 217


South San Francisco, California



(Address of principal executive offices)


(Zip Code)


Registrant’s telephone number, including area code: (650) 484-0899



(Former name or former address, if changed since last report)


Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class




Name of each exchange on which registered

Common Stock, par value $0.0001 per share




NASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.



Item 7.01 Regulation FD Disclosure.

On April 13, 2022, Day One Biopharmaceuticals, Inc. (the "Company") updated its corporate presentation.


A copy of the updated corporate presentation is attached as Exhibit 99.1 to this Current Report on Form 8-K. The corporate presentation is also available on the Company’s website in the Events & Presentations section at www.dayonebio.com.


The information in this item 7.01, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (“Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01 Financial Statements and Exhibits.
















Corporate Presentation.






Cover Page Interactive Data File (embedded within the Inline XBRL document).




Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.










April 13, 2022


/s/ Charles N. York II, M.B.A.




Charles N. York II, M.B.A.
Chief Operating Officer and Chief Financial Officer


Slide 1

Targeted Therapies for People of All Ages April 2022

Slide 2

Disclaimer This presentation and the accompanying oral commentary contain forward-looking statements that are based on our management’s beliefs and assumptions and on information currently available to our management. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. In some cases, you can identify forward-looking statements by terminology such as “may,” “will,” “should,” “could,” “expect,” “plan,” anticipate,” “believe,” “estimate,” “predict,” “intend,” “potential,” “would,” “continue,” “ongoing” or the negative of these terms or other comparable terminology. Forward-looking statements include all statements other than statements of historical fact contained in this presentation, including information concerning our future financial performance, business plans and objectives, timing and success of our planned nonclinical and clinical development activities, timing and results of nonclinical studies and clinical trials, efficacy and safety profile of our product candidates, our ability to obtain regulatory approval, the potential therapeutic benefits and economic value of our product candidates, potential growth opportunities, competitive position, industry environment and potential market opportunities, and the impact of the COVID-19 pandemic on our business and operations. Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. These factors, together with those that are described under the heading “Risk Factors” contained in our most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) and other documents we file from time to time with the SEC, may cause our actual results, performance or achievements to differ materially and adversely from those anticipated or implied by our forward-looking statements. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this presentation, and although we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted a thorough inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all. We undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions, and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

Slide 3

Day One: Cancer Drug Development for People of All Ages Mission That Creates Value Specialized Team Tovorafenib (DAY101) Lead Program Growing Portfolio and Runway Beyond Clinical Milestones Develop medicines for genomically-defined cancers Goal is to establish first-in-class position through rapid pediatric registration Expand to adult populations in parallel Deep expertise in oncology, pediatric, and rare disease development, registration, and commercialization Extensive network in the global pediatric oncology community Proven track record of success in building biopharma companies Potential to be first-in-class oral, CNS-penetrant pan-RAFi Potentially the first approval in a market with no standard of care Monotherapy CRs and PRs in pediatric low-grade glioma (pLGG) Breakthrough Therapy Designation, Rare Pediatric Disease Designation Two clinical-stage MEKi assets, in-licensed for combination trial Projected cash runway into 2024 Capital through pivotal data in pLGG and early adult solid tumor Phase 1b data

Slide 4

Pediatric Markets Create Opportunity for High Impact and Capital Efficiency Lack of approved products create potential first-in-class opportunities Pricing flexibility for important new therapies Supportive and engaged advocacy and investigator community desiring better treatment options Early engagement with global regulatory authorities Small trials and clear endpoints that permit rapid development to clinical proof-of-concept and potential approval Many pediatric tumors are genetically simple and genomically stable Genetic alterations are often oncogenic Rapid clinical development Enriched responder populations informed by underlying biology Regulatory and reimbursement tailwinds

Slide 5

A Senior Team with Deep Experience Developing and Commercializing Products in Pediatric and Adult Oncology Markets Mike Preigh, PhD Chief Technical Officer Head of CMC at Array for 10+ years. Brought >20 drug candidates to IND & clinical development Lisa Bowers Chief Commercial Officer CEO of Rhia Ventures, COO of The Tara Health Foundation, VP of the North American Supply Chain and Commercial Leader at Genentech Davy Chiodin, PharmD Chief Development Officer VP Regulatory Science, Acerta/AZ; Global Regulatory Leader, Pediatric Oncology, Roche/Genentech Samuel Blackman, MD, PhD Chief Medical Officer & Founder Pediatric Heme/Onc and Neuro-Onc; Oncology Clinical Development at Mavupharma, Silverback, Juno, Seattle Genetics, GSK Jeremy Bender, PhD, MBA Chief Executive Officer VP of Corporate Development at Gilead; COO Tizona Therapeutics; CBO Sutro Biopharma; founding Board member of VaxCyte Charles York II, MBA Chief Operating and Financial Officer CFO and Head of Corporate Development at Aeglea; Consulting CFO at Bridgepoint Consulting; PricewaterhouseCoopers Jaa Roberson Chief People Officer Head of Human Resources at Bellicum Pharmaceuticals; Human Resources Roles at Achaogen, Roche/Genentech

Slide 6

Our Pipeline Product Candidate Indication Preclinical Phase 1 Phase 2 Phase 3 Milestones Tovorafenib (DAY101) Type II Pan-RAF Inhibitor Relapsed pLGG Frontline pLGG RAF-altered solid tumors2 (monotherapy) Pimasertib MEK 1/2 Inhibitor MAPK-altered solid tumors3 (Combo w/DAY101) FDA Breakthrough Therapy Designation FDA Orphan Drug Designation EC Orphan Designation FDA Rare Pediatric Disease Designation (PRV Eligible) FIREFLY-11 (pivotal) FIREFLY-2 (planned) FIRELIGHT-1* FIRELIGHT-1* 2DAY101 adult monotherapy Phase 1 dose escalation and expansion trial previously completed 3Pimasertib Phase 1 dose escalation and expansion trial previously completed *Includes patients ≥12 years of age pLGG = pediatric low-grade glioma 1Pivotal Phase 2 trial expected to support registration Target enrollment achieved: March 2022 Initial data: June 2022 Topline data: 1Q 2023 Phase 3 initiation: 2Q 2022 First patient dosed: November 2021 Phase 1b/2 initiated: March 2022

Slide 7

Tovorafenib (DAY101) Type II Pan-RAF Inhibitor

Slide 8

Tovorafenib (DAY101): Monotherapy Approach is Focused on RAF Fusions While Our Combination Strategy Addresses a Broad Set of MAPK Alterations Tovorafenib (DAY101) is a type II RAF inhibitor that selectively inhibits both monomeric and dimeric RAF kinase Tovorafenib’s inhibition of both RAF monomers and dimers makes it a unique monotherapy approach for patients with tumors driven by RAF wild-type fusions, and a bespoke therapy for pediatric low-grade gliomas Unlike type I RAF inhibitors, tovorafenib does not cause paradoxical activation in RAF wild-type cells Approved BRAF products (e.g. vemurafenib, encorafenib) are type I RAF inhibitors that only inhibit RAF monomers and are therefore limited to use in BRAF V600-altered tumors Type I inhibitors can also cause paradoxical activation of the MAPK pathway, which could potentially lead to increased tumor growth Adapted from: Yaeger and Corcoran, Cancer Discovery, 2019 Type I Type II BRAF V600E ATP BRAF V600E Drug BRAF V600E Drug RAF ATP RAF ATP RAF Drug RAF ATP RAF RAF Drug Drug RAF monomeric kinase RAF dimeric kinase Momomer-selective RAF inhibitor (e.g. vemurafenib, dabrafenib, encorafenib) RAF dimer inhibitor (e.g., LXH254, LY3009120) Tovorafenib (DAY101), in combination with MEK inhibitors, may act synergistically to inhibit tumors driven by other MAPK alterations and broadens its potential clinical applications

Slide 9

The Current pLGG Treatment Paradigm Reflects the Unrelenting Nature of this Chronic Brain Tumor Because many pLGGs undergo senescence when patients reach their 20s, the goal of therapy is to maximize tumor control while minimizing treatment-associated toxicities from surgery, chemotherapy, and radiation. As a result, a large number of pLGG patients will undergo multiple lines of systemic therapy over the course of their disease. Surgical Intervention Chemo (90%) Other (<5%) Targeted Tx (5-10%) Suspected pLGG GTR No Recurrence Eventual Recurrence 80% 20% 35% Presentation 1L 2L 3L Response, no recurrence ~35% Chemo (50%) Other (<5%) Targeted Tx (40-50%) Chemo (35%) Other (<20%) Targeted Tx (40-50%) Response, no recurrence ~50% ~65% ~50% Biopsy Only 40% 20% Molecular Testing Biopsy1 (>95%) No Biopsy (5%) ≤ Partial Resection ~50% Additional lines of therapy Source: Physician Interviews, Bandopadhayay et al. Pediatric Blood Cancer. 2014; Sievert and Fischer. J Child Neurol. 2009; ClearView Analysis. GTR: Gross Total Resection 1Molecular testing of biopsied samples occurs in all patients. Kandels et. al. Retrospective analysis of comprehensive SIOP registry; Hargrave et. al. Phase I/II;Fangusaro et. al. Phase II

Slide 10

PNOC014 Study Results Demonstrated Responses or Stable Disease in Majority of pLGG Patients Treated with Tovorafenib (DAY101) Of the eight patients with RAF fusions (7 BRAF, 1 CRAF), two patients achieved a complete response by Response Assessment for Neuro-Oncology (RANO), three had a partial response, and two achieved prolonged stable disease Median time to achieve a response was 10.5 weeks, with most common side effects being skin rash and hair color changes. Most patients treated up to two years at 420 mg/m2/week US FDA has granted DAY101 Breakthrough Therapy designation for the treatment of pediatric patients with advanced low-grade glioma harboring RAF alteration and Orphan Drug Designation for the treatment of malignant glioma Tovorafenib (DAY101) studied as once-weekly monotherapy in a Phase 1 dose escalation trial in relapsed pediatric glioma patients conducted by the Dana-Farber Cancer Institute and the Pacific Pediatric Neuro-Oncology Consortium (PNOC) Once Weekly Tovorafenib (DAY101) Complete Response Partial Response Prolonged Stable Disease

Slide 11

Results from Independent Radiology Review of PNOC014 RAPNO: Response assessment for pediatric neuro-oncology (exploratory) RANO: Response assessment for neuro-oncology (FDA standard) Volumetric image analysis (exploratory) Best response from baseline Date of data cutoff: 02 JAN 2020 Wright K et. al. Neuro Oncology Abstract CTNI-19. 2020

Slide 12

Multiple Rapid, Deep and Durable Responses Observed following Initiation of Tovorafenib (DAY101) Treatment of pLGG Patients in PNOC014 Date of data cutoff: 02 JAN 2020 Adapted from Wright K et. al. Neuro Oncology Abstract CTNI-19. 2020 Fangusaro J et al. Lancet Oncol 2019

Slide 13

Drug-related Adverse Events Observed for Tovorafenib (DAY101) in PNOC014 Showed Favorable Safety and Tolerability Profile in pLGG Toxicities Grade 1-2 Grade 3 Grade 4 Anemia 6 (67%) Hypophosphatemia 4 (44%) Fatigue 5 (55%) Rash 8 (89%) Achromotrichia 7 (78%) Pruritis 6 (67%) Photosensitivity 1 (11%) Nevus 7 (78%) Alopecia 3 (34%) Epistaxis 2 (22%) Dry skin 3 (34%) Myalgias/arthralgias 3 (34%) Anorexia 2 (22%) Cheilitis 3 (34%) Hypermagnesemia 1 (11%) Bleeding gums 1 (11%) Increased AST 4 (44%) Nausea/vomiting 3 (33%) CPK elevation 1 (11%) Weight loss 2 (22%) DAY101 AE summary Most common toxicity: skin AEs reversible and all manageable Single, reversible Grade 3 event No Grade 4 AEs No dose reductions (vs. 40% of patients on selumetinib montherapy required dose reductions) Drug-related AEs for Tovorafenib (DAY101) Toxicities Grade 1-2 Grade 3 Grade 4 Increased ALT 20 (40%) 1 (2%) CPK elevation 34 (68%) 5 (10%) Diarrhea 27 (54%) 2 (4%) Decreased ejection fraction 19 (38%) 1 (2%) Gastric haemorrhage 1 (2%) Headache 14 (28%) 1 (2%) Decreased lymphocyte count 19 (38%) 1 (2%) Neutropenia 14 (28%) 3 (6%) Paronychia 19 (38%) 3 (6%) Rash (acneiform) 29 (58%) 2 (4%) Rash (maculopapular) 26 (52%) 5 (10%) Skin infection 7 (14%) 1 (2%) Tooth infection 1 (2%) Weight gain 5 (10%) 1 (2%) Vomiting 22 (44%) Nausea 21 (42%) Increased AST 25 (50%) Anemia 28 (56%) Pruritis 10 (20%) Dyspnea 30 (60%) Drug-related AEs for selumetinib Date of DAY101 data cutoff: 02 JAN 2020; Wright K et. al. Neuro Oncology Abstract CTNI-19. 2020; Fangusaro J et al. Lancet Oncol 2019

Slide 14

Pivotal Phase 2 Study of Monotherapy Tovorafenib (DAY101) in pLGG (FIREFLY-1) Abbreviations: LGG, low-grade glioma; ORR, objective response rate; C, cycle; D, day Study Design Screening Day –28 to 0 Enrollment/Baseline (C1D1) MRI: Baseline and every 3rd cycle Study Drug Administration 420mg/m2 QW Eligibility evaluation Treatment period: minimum of 2 years or until progression or toxicity/intolerability C27D1 After Cycle 27: patients may either continue treatment or enter drug holiday period at any time (at discretion of Investigator) End of Study (Patient #60, Cycle 27) Trial Design Single arm, open-label, global registrational phase 2 study n = 60 patients (approximately) Eligibility: Patients aged 6 months – 25 years with LGG harboring a KIAA1549:BRAF wild-type fusion or BRAF V600 mutation Endpoints Primary endpoint: ORR based on RANO criteria, assessed by independent review Secondary endpoints: ORR by RAPNO criteria; EFS; safety

Slide 15

Key Product Attributes for pLGG Prescribers When Choosing a New Therapy Relative Importance of attributes PFS & ORR Safety while on therapy Functional Improvement & Long-Term Safety Dosing and Administration FDA Approval “You want to make sure the treatment is not worse than the disease, and you are not making their QoL worse. These are just children.” “As we are dealing with the brain, we need to make sure these patients can function. We want to make sure they can do their daily activity, and maintain motor functions and vision… this is very important for their QoL.” “Pediatric dosing is very important, but efficacy and safety are a lot more important than the delivery of the drug.” “Efficacy, especially ORR and PFS, are the most important. You want these patients to live without progression of pLGG for as much time as possible, and for the treatment to be effective for the majority of these patients.” MOA “Without an indication, insurance may not pay for it… it would be a higher burden for families… an FDA-approved indication also means the therapy meets general safety and efficacy regulations, so that is always a plus.” “I don’t really care about the mechanism of action, as long as the drug works, and there are no big concerns with toxicity.” Stable Disease “We tell our patients that the goal is to kill the tumor, but the more practical goal is to stop it from growing. Even if we achieve stable tumors, that’s considered a success.”  Sources: pLGG Buying Process; pLGG Demand Study

Slide 16

Incidence and Prevalence of BRAF-altered pLGG in the U.S. 2020 Estimated Incidence Under 25 US Population1 ~105,000,000 Rate of CNS Tumors (0.00521%)2 ~5,500 Gliomas (63%)2 ~3,500 Low Grade (77%)2 ~2,600 Has Received Drug Tx (58%)2 ~1,500 BRAF Mutated (70%)2 ~1,100 2017 Estimated SEER Prevalence Under 25 NA ~130,0003 ~82,000 ~63,000 ~36,000 ~26,000 ~1,100 Estimated Annual Incidence ~26,000 Estimated Prevalence (SEER) 1US Census; 2CBTRUS, Qaddoumi et al 2009, Schreck et al 2019, ClearView Analysis; 3SEER US complete prevalence counts of patients aged under 25 with Brain and Other Nervous Systems tumors as of January 1, 2017. Estimated annual incidence and estimated prevalence (SEER) are Day One calculations based on publicly available data.

Slide 17

Our Pipeline Product Candidate Indication Preclinical Phase 1 Phase 2 Phase 3 Anticipated Milestones Tovorafenib (DAY101) Type II Pan-RAF Inhibitor Relapsed pLGG Frontline pLGG RAF-altered solid tumors2 (monotherapy) Pimasertib MEK 1/2 Inhibitor MAPK-altered solid tumors3 (Combo w/DAY101) FDA Breakthrough Therapy Designation FDA Orphan Drug Designation EC Orphan Designation FDA Rare Pediatric Disease Designation (PRV Eligible) FIREFLY-11 (pivotal) FIREFLY-2 (planned) FIRELIGHT-1* FIRELIGHT-1* 2DAY101 adult monotherapy Phase 1 dose escalation and expansion trial previously completed 3Pimasertib Phase 1 dose escalation and expansion trial previously completed *Includes patients ≥12 years of age pLGG = pediatric low-grade glioma 1Pivotal Phase 2 trial expected to support registration Phase 3 initiation: 2Q 2022 First patient dosed: November 2021 Phase 1b/2 initiated: March 2022 Target enrollment achieved: March 2022 Initial data: June 2022 Topline data: 1Q 2023

Slide 18

Tovorafenib (DAY101) is Active as a Monotherapy in Patients with RAF-altered Adult Solid Tumors and Has Shown Strong Synergy Preclinically in Combination Clinical activity demonstrated in relapsed melanoma patients; preclinical activity demonstrated in RAF fusions, BRAF non-V600 mutations, and BRAF V600 mutations Less frequent and less severe acneiform rash No observed ophthalmologic liabilities (RVO/CSR) No observed CV liabilities (changes in LVEF) No type I BRAF SAEs: SCCs/KAs, pyrexia, arthralgia Same study will include combination cohorts of tovorafenib (DAY101) + pimasertib First patient dosed in Phase 2 monotherapy study in November 2021 >225 adult patient exposures Responses in BRAF V600E mutant tumors similar to type I BRAF inhibitors Responses in relapsed BRAF and NRAS-mutant melanoma, suggesting tovorafenib (DAY101) may be active in tumors currently unaddressed by approved Type I BRAF inhibitors Differentiated safety profile for tovorafenib (DAY101) vs. existing BRAF and MEK inhibitors We initiated an adult solid tumor study to further evaluate monotherapy tovorafenib (DAY101) in patients with RAF altered tumors for which there are no currently approved therapies Source: Olszanski AJ et. al. European Society for Medical Oncology Congress; Poster #410P, 2017 Unpublished clinical study results

Slide 19

Activity of Tovorafenib (DAY101) in SNX8:BRAF Fusion Spindle Cell Sarcoma Baseline After 2 cycles of tovorafenib Diagnosis BRAF fusion (FISH) CR PD CR Subtotal resection Gemcitabine, docetaxel Trametinib Ifosfamide, doxorubicin, dexrazoxane Proton radiotherapy SNX8-BRAF fusion Months -30 -24 -18 -12 -6 0 6 Tovorafenib Tovorafenib After the first dose of tovorafenib (DAY101), the patient experienced grade 2 rash, which resolved in a day following a dose of diphenhydramine Radiotherapy-related adverse events included hyperpigmentation overlying the spine on the upper back with no skin breaks, and mild dysphagia Data cut off: September 30, 2021 A male child with spindle cell sarcoma, 5-years of age at diagnosis

Slide 20

Next-generation RAF Inhibitors are Unique in Their Ability to Address Adult Cancers Associated with RAF Wild-type Fusions Botton T et al, Cell Reports, 2019 LY3009120: Lilly pan-RAFi Lifirafenib: Beigene pan-RAF/EGFRi CCT196969: CRUK RAF ”paradox breaker” Springworks 2020 Corp Presentation BRAFwt fusion mixed Mullerian cancer BRAFwt fusion, melanoma Day One/CrownBio internal data E5251-U2001 (Sep 2020) Only tovorafenib (DAY101) has demonstrated monotherapy clinical activity in KIAA1549:BRAF and SRGAP3:CRAF wild-type fusions in pLGG Gouda M et al, ESMO 2020 CR observed at 1800 mg BID = 3x higher total AUC over 900 mg BID Activity of BRAF dimer-breaker PLX-8394 in BRAF wild-type fusion melanoma

Slide 21

Phase 2 Study of Monotherapy Tovorafenib (DAY101) in Solid Tumors (FIRELIGHT-1) Trial Design1 Single arm, open-label, global phase 1b/2a study n = 40 patients (approximately) Eligibility: Patients aged 12 years and older with non-hematologic tumor with an activating BRAF fusion, CRAF/RAF1 fusion, or CRAF/RAF1 amplification Endpoints Primary endpoint: ORR by RECIST version 1.1 for non-CNS solid tumors and RANO criteria for any CNS tumors Secondary endpoints: safety and additional efficacy parameters DAY101 QW until disease progression2 Safety Follow Up Patients with a known BRAF or CRAF/RAF1 fusion, or CRAF/RAF1 amplification Melanoma cohort “Tissue agnostic” cohort Study Drug Administration ≥ 18 years at 600 mg PO QW 12 to <18 years at 420mg/m2 PO QW Abbreviations: ORR, objective response rate; QW, once weekly ; PO, by mouth; BRAF, B-Raf proto-oncogene. 1Umbrella master study – DAY101-102 (main protocol) DAY101 and MAPK pathway aberration, Sub-study 1 monotherapy (DAY101-102a), Sub-study 2 MEK combo (DAY101-102b). 2DAY101 QW until disease progression, intolerable toxicity, withdrawal of consent, or death

Slide 22

Strong Scientific Rationale for Combining Tovorafenib (DAY101) with Additional MAPK Pathway Inhibitors Potential combinations Type II RAFi + MEKi Rationale BRAF fusion dimers are effectively inhibited by type II, but not type I RAFi MEK ERK RAF/MEK/ ERK PI3K/mTOR RAL Type II RAFi + Targeting multiple nodes of MAPK pathway will drive deeper and more durable response Signaling pathways Proliferation, survival Proliferation, survival RAS/RAF/MEK/ERK PI3K/ mTOR Proliferation, survival Type II RAFi + SHP2i Targeting multiple pathways will drive deeper response Type II RAFi + Non V600 BRAF dimers are effectively inhibited by type II, but not type I, RAFi MEK ERK Proliferation, survival SHP2i MEKi or SHP2i MEKi or KRAS- G12Ci or BRAF non-V600 BRAF or CRAF WT fusion KRAS or NRAS mutant NF1 LOF

Slide 23

Pimasertib MEK1/2 Inhibitor

Slide 24

Pimasertib: Allosteric MEK1/2 Inhibitor with Demonstrated Activity in MAPK-driven Solid Tumors Sources: Pimasertib Investigator Brochure, v12, 2019; de Gooijer et al., Int J Cancer, 2018; Shaw et al., AACR LB-456, 2012; Lebbe et al., Cancers, 2020. Pimasertib is an orally-bioavailable, selective, non-competitive MEK1/2 inhibitor in-licensed from Merck KGaA in February 2021 Extensive non-clinical and clinical development work through Phase 2, including a solid tumor trial in Japan and combinations with other MOAs Main AEs typical for all in-class allosteric MEK inhibitors (GI, CPK elevation, skin rash, visual disturbances) Nearly three-fold higher CNS penetration than other MEKi inhibitors (trametinib or selumetinib) Pimasertib showed monotherapy clinical activity, including an improvement in median PFS versus dacarbazine in NRAS mutant melanoma Combination with tovorafenib (DAY101) and other targeted therapies may unlock the full value of pimasertib in advanced solid tumors Source: Hepner, Salgues, Anjos, et al. 2017. GF RTKS NRAS BRAF MEK ERK Cell growth and survival Nuclear membrane GTP Gene transcription Cellular membrane MEKi BRAFi

Slide 25

Vertical MAPK Pathway Inhibition with Tovorafenib (DAY101) and Pimasertib Unlocks Potential Synergy for Adult Solid Tumors The MAPK pathway normally has multiple feedback loops that negatively regulate upstream (RAS/RAF) activation to ensure optimal signaling Monotherapy MEK inhibition disables these feedback loops and induces RAS signaling as well as RAF dimerization and activation Combination therapy with a MEK inhibitor and type II RAF inhibitor is synergistic in KRASmut and BRAFmut tumor models Mechanistic model for vertical MAPK pathway inhibition (modified from Yen et al. Cancer Cell, 2018) . DAY101 + MEK inhibitor is synergistic in KRAS G12C and Q61 mutant tumor cell models (Day One internal data) Sensitivity of KRAS Q61 mutant cells to pimasertib is enhanced when cells are treated with the type II RAF inhibitor BGB-283 (Yuan et al., Mol Onc 2020) Modified from Yen et al. Cancer Cell, 2018 A B C

Slide 26

Tovorafenib (DAY101) / Pimasertib Combination to be Evaluated in Solid Tumors (FIRELIGHT-1) Abbreviations: BOIN, Bayesian Optimal Interval Design; BRAF, B-Raf proto-oncogene, serine/threonine kinase; MAPK, mitogen-activated protein kinase; NRAS, neuroblastoma rat sarcoma viral oncogene. 1Umbrella master study – DAY101-102 (main protocol) DAY101 and MAPK pathway aberration, Sub-study 1 monotherapy (DAY101-102a), Sub-study 2 MEK combo (DAY101-102b). 2Intend to open U.S. and ex-U.S. clinical sties. 3DAY101 + Pimasertib until disease progression, intolerable toxicity, withdrawal of consent, or death Trial Design1 Combination dose escalation, global phase 1b/2 study2 Phase 1b, BOIN (adaptive), n = 10/cohort (approximately) Phase 2, Simon 2-stage, n = 25/cohort (approximately) Eligibility: Patients aged 12 years and older, dose escalation will be performed in advanced solid tumor patients with any MAPK alteration. Expansion cohorts will focus on indications with a potential path to accelerated approval Endpoints Phase 1b: PK, PD and Safety, MTD/RP2D Phase 2: Efficacy (ORR, DOR) DAY101 + Pimasertib until disease progression3 NRASmut Selected tumors BRAF Class 1 (non-E/K) and Class 2 mutant tumors BRAF wt fusion selected tumors Pre-identified patients with advanced solid tumors and available clinical molecular profiling information. *Additional biomarker-selected cohorts may be pursued based on developing data Safety Follow Up Tumors with MAPK pathway alterations Phase 1b Phase 2*

Slide 27


Slide 28

Financial Summary: DAWN Cash and cash equivalents as of December 31, 2021: $284.3 million (no debt) IPO in May 2021: $184 million in gross proceeds, includes full exercise of underwriters’ option 62.0 million shares of common stock outstanding $ Millions Three Months Ended 12/31/21 Twelve Months Ended 12/30/21 R&D Expense $11.2 $43.6 G&A Expense $10.8 $29.2 Net Loss $21.9 $72.8 All financial and share information is unaudited Projected cash runway into 2024 FIREFLY-1: Pivotal Phase 2 clinical trial of tovorafenib (DAY101) Initial clinical data expected in June 2022 Target enrollment achieved; full topline results expected in 1Q 2023 Anticipated NDA filing in 2023, if data from FIREFLY-1 are supportive FIRELIGHT-1: Tovorafenib (DAY101) and pimasertib combination Trial initiated in March 2022

Slide 29

Momentum for a More Inclusive Era of Drug Development, Starting at Day One Pursuing Fast-to-Market Pediatric and Adult Targeted Therapies Key Highlights Tovorafenib (DAY101)1 FIREFLY-1 (Relapsed pLGG) First patient dosed in Pivotal FIREFLY-1 trial: May 2021 Target enrollment achieved: March 2022 Breakthrough Therapy Designation & Rare Pediatric Disease Designation FIFELIGHT-1 (RAF-altered solid tumors - monotherapy) First patient dosed in phase 2 monotherapy trial: November 2021 Intellectual Property Composition of matter to mid-2030s with PTE, potential exclusivity to late 2030s / early 2040s via broad patent portfolio Pimasertib1 FIFELIGHT-1 (MAPK-altered solid tumors – Combo w/Tovorafenib) Initiated combination dose escalation, global phase 1b/2 trial: March 2022 2022 Outlook Tovorafenib (DAY101) FIREFLY-1 (Relapsed pLGG) Initial data expected: June 2022 Topline data expected: 1Q 2023 FIREFLY-2 (Frontline pLGG) Phase 3 trail initiation: 2Q 2022 1 Worldwide rights for all indications

Slide 30

Thank you