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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 10-K
(Mark One)
☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31, 2021
OR
☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from _______to _______
Commission file number: 001-39592
Kronos Bio, Inc.
(Exact name of registrant as specified in its charter)
| | | | | |
| Delaware | 82-1895605 |
(State or other jurisdiction of incorporation or organization) | (I.R.S. Employer Identification Number) |
1300 So. El Camino Real, Suite 400
San Mateo, California 94402
(650) 781-5200
(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)
Securities registered pursuant to Section 12(b) of the Act:
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| Title of each class | Trading Symbol(s) | Name of each exchange on which registered |
| Common stock, $0.001 par value per share | KRON | The Nasdaq Stock Market LLC |
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒.
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒.
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. ☒ Yes or ☐ No.
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Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
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| Large accelerated filer | ☒ | Smaller reporting company | ☐ |
| Non-accelerated filer | ☐ | Accelerated filer | ☐ |
| | 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. ☐
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Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). ☐ Yes or ☒ No
The aggregate market value of the voting and non-voting common equity held by non-affiliates of the registrant as of June 30, 2021 (the last business day of the registrant’s most recently completed second fiscal quarter) was approximately $1.3 billion based on the closing price of the registrant’s common stock on June 30, 2021 of $23.95 per share, as reported by The Nasdaq Global Select Market.
As of February 18, 2022, the registrant had 56,601,965 shares of common stock, $0.001 par value per share, outstanding.
DOCUMENTS INCORPORATED BY REFERENCE
Portions of the registrant’s definitive proxy statement to be filed with the Securities and Exchange Commission (SEC) subsequent to the date hereof pursuant to Regulation 14A in connection with the registrant's 2022 Annual Meeting of Stockholders, are incorporated by reference into Part III of this Annual Report on Form 10-K. Such proxy statement will be filed with the SEC not later than May 2, 2022.
TABLE OF CONTENTS
FORWARD-LOOKING STATEMENTS
This Annual Report on Form 10-K contains forward-looking statements about us and our industry that involve substantial risks and uncertainties. All statements other than statements of historical fact contained in this report, including statements regarding our strategy, future financial condition, future operations, research and development, planned clinical trials and preclinical studies, expected progress and milestones related to our clinical and preclinical programs, the timing and likelihood of regulatory filings and approvals for our product candidates, our ability to commercialize our product candidates, the potential benefits of collaborations, projected costs, prospects, plans, objectives of management and expected market growth, are forward-looking statements. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “positioned,” “potential,” “predict,” “seek,” “should,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms or other comparable terminology.
We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our financial condition, results of operations, business strategy and financial needs. These forward-looking statements are subject to a number of known and unknown risks, uncertainties and assumptions described in the sections of this report titled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this report. Other sections of this report may include additional factors that could harm our business and financial performance. 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 report, and while 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 an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and you are cautioned not to unduly rely upon these statements.
Moreover, we operate in a very competitive and rapidly changing environment. New risk factors emerge from time to time, and it is not possible for our management to predict all risk factors 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, or implied by, any forward-looking statements.
In light of the significant uncertainties in these forward-looking statements, you should not rely upon forward-looking statements as predictions of future events. Although we believe that we have a reasonable basis for each forward-looking statement contained in this report, we cannot guarantee that the future results, levels of activity, performance or events and circumstances reflected in the forward-looking statements will be achieved or occur at all. You should refer to the section of this report titled “Risk Factors” for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. Except as required by law, we undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.
You should read this report and the documents that we reference in this report and have filed as exhibits to this report completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in this report by these cautionary statements.
RISK FACTOR SUMMARY
Below is a summary of material factors that make an investment in our common stock speculative or risky. This summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary, and other risks that we face, can be found below under the heading “Risk Factors” in Item 1A of Part I of this Annual Report on Form 10-K, and should be carefully considered, together with other information in this Annual Report on Form 10-K and our other filings with the SEC before making investment decisions regarding our common stock.
•We have incurred significant net losses since inception and we expect to incur significant losses over the next several years and may not be able to achieve or sustain revenues or profitability in the future.
•We will need substantial additional funding. If we are unable to raise capital when needed, we may be compelled to delay, reduce, or eliminate our product development programs or commercialization efforts.
•We have a limited operating history and face significant challenges and will incur substantial expenses as we build our capabilities.
•Our discovery and development activities are primarily focused on novel cancer therapeutics for patients with genetically-defined cancers and it is difficult to predict the time and cost of developing our product candidates and obtaining regulatory approval.
•We have encountered and may continue to encounter delays and difficulties initiating clinical trial sites and enrolling patients in our clinical trials, and, as a result, our clinical development activities could be delayed or otherwise adversely affected.
•Our approach to the discovery and development of product candidates is unproven, and we may not be successful in our efforts to use and further develop our product engine to expand our pipeline of product candidates with commercial value.
•We plan to attempt to secure approval for entospletinib and possibly other of our product candidates from the U.S. Food and Drug Administration (FDA) or comparable regulatory authorities through the use of accelerated approval pathways, which is uncertain.
•The COVID-19 pandemic could continue to adversely impact our business, including our ongoing and planned clinical trials.
•If the market opportunities for our product candidates are smaller than we estimate or if any regulatory approval that we obtain is based on a narrower definition of the patient population, it will adversely affect our revenue potential and ability to achieve profitability.
•Our success depends in part on our ability to protect our intellectual property and our proprietary products and technologies and obtain, maintain and enforce our intellectual property, as well as our ability to operate without infringing the patents and other proprietary rights of third parties.
•We rely, and expect to rely in the future, on third parties, including independent clinical investigators, developers of companion diagnostics, and contract research organizations to conduct certain aspects of our preclinical studies and ongoing and planned clinical trials. We also rely, and expect to rely in the future, on contract manufacturing organizations for the manufacture of our product candidates for preclinical and clinical testing, as well as manufacture of any products that we may commercialize.
•Our success is highly dependent on our ability to attract and retain highly-skilled executive officers and employees.
TRADEMARKS AND SERVICE MARKS
“Kronos Bio,” “Kronos,” the Kronos logo and other trademarks, trade names or service marks of Kronos Bio, Inc. appearing in this report are the property of Kronos Bio, Inc. All other trademarks, trade names and service marks appearing in this report are the property of their respective owners. Solely for convenience, the trademarks and trade names in this report may be referred to without the ® and ™ symbols, but such references should not be construed as any indicator that their respective owners will not assert their rights thereto.
PART I.
ITEM 1. BUSINESS
Overview
We are an integrated discovery through late-stage clinical development biopharmaceutical company, with a focus on developing therapeutics that target the dysregulated transcription that causes cancer and other serious diseases. We have two investigational compounds in clinical trials, including one in a pivotal Phase 3 trial, and a third compound that we anticipate will enter the clinic in the first quarter of 2022. Our product engine, which includes our proprietary small molecule microarray screening platform, provides us with the capability to map and target transcription regulatory networks (TRNs) in a differentiated manner to enable discovery of novel compounds and improve our translational capabilities.
Our lead product candidate, entospletinib, is an orally administered, selective spleen tyrosine kinase (SYK) inhibitor that has been previously tested in more than 1,300 people, including more than 200 patients with acute myeloid leukemia (AML). Based on clinical results in a biomarker-defined subset of patients and following discussions as part of an End-of-Phase 2 meeting with the FDA, we have initiated our randomized, double-blinded, placebo-controlled registrational Phase 3 clinical trial of entospletinib in combination with intensive chemotherapy in approximately 180 patients with newly diagnosed NPM1-mutated AML. We are also developing lanraplenib, our next-generation orally-administered SYK inhibitor, and plan to initiate a Phase 1b/2 clinical trial in the first quarter of 2022. This clinical trial will evaluate lanraplenib in combination with gilteritinib in patients with relapsed or refractory FLT3-mutated AML. In addition, we are developing KB-0742, our internally discovered, oral cyclin dependent kinase 9 (CDK9) inhibitor, for the treatment of MYC-amplified and other transcriptionally addicted solid tumors. The first patient in our Phase 1/2 clinical trial was dosed in February 2021, and we reported initial data in the fourth quarter of 2021.
In our research efforts, we are leveraging our product engine to drive multiple oncology discovery programs targeting dysregulated transcription factors and their associated TRNs. Some of the most powerful oncogenes in all of human cancer encode transcription factors: proteins that bind to specific DNA sequences on the genome and control how sets of genes are turned on and off. Transcription factors historically have been difficult to target in drug development because they are typically intrinsically disordered, adopting a functional structure only when assembled with a complex of cofactors in the nucleus on the genome. Transcription factors with aberrant expression or activity result in dysregulated TRNs, which are frequently responsible for reprogramming healthy cells into cancerous tumor cells. Therapeutically modulating dysregulated transcription factors requires a sophisticated and holistic approach due to their complexity and their regulation of complex TRNs in a context-dependent manner. Based on this work, in November 2021, we announced the advancement of two programs, one focused on the MYC TRN and one focused on the androgen receptor (AR) TRN.
We take a systems biology approach to unlocking therapeutic mechanisms within dysregulated TRNs using our differentiated product engine. Our product engine includes three interconnected components, each of which is informed by our translational expertise, and which we believe enables efficient discovery and development of new product candidates:
•Map TRNs – Leverage our computational biology expertise, engineered cell systems and high throughput transcriptomic profiling to map the structure of TRNs defined by specific dysregulated transcription factors and identify the gene expression signature of selective TRN modulation that can be carried forward into discovery and clinical translation.
•Define Dependencies – Apply causal and mechanistic insights to analyze TRNs and to identify critical nodes that may represent tractable targets for drug discovery. We do this by identifying which genetic sequences transcription factors bind to, which proteins they interact with, and which genes they regulate in specific cellular contexts.
•Identify Modulators – Conduct high throughput screens using our proprietary small molecule microarray (SMM) screening platform against dysregulated transcription factors in tumor cell lysates to identify selective TRN modulators and determine mechanism of action. Such modulators are then further optimized to refine their pharmacological properties.
Entospletinib and Lanraplenib
Our lead product candidate, entospletinib, is a selective inhibitor of SYK, a critical node in a dysregulated TRN within AML defined by persistent high expression of the transcription factors HOXA9 and MEIS1 (HOX/MEIS). Through analysis of AML patient sample datasets compiled by various academic collaborator groups, we selected NPM1 mutation as a robust genomic biomarker of HOX/MEIS elevation in AML. NPM1 mutation is reported to be present in approximately one-third of adult AML patients. We believe that utilizing an NPM1 mutation test, both for patient selection and assessment of measurable residual disease (MRD) negative complete response (CR) as a registrational endpoint enables a highly efficient regulatory path for seeking potential accelerated approval. We held an End-of-Phase 2 meeting with the FDA to discuss our proposed design, endpoints and companion diagnostic strategy for our planned entospletinib registrational trial in patients with NPM1-mutated AML. Based upon the discussion and guidance from the meeting with FDA, we initiated our registrational Phase 3 AGILITY clinical trial of entospletinib using MRD-negative CR as the primary endpoint. We announced the dosing of the first patient in that study in December 2021. The trial is designed to evaluate entospletinib in combination with standard of care anthracycline and cytarabine (7+3) chemotherapy in patients newly diagnosed with NPM1-mutated AML who are fit for intensive induction.
We are also developing a next-generation SYK inhibitor, lanraplenib, and anticipate beginning a Phase 1b/2 trial in the first quarter of 2022. Lanraplenib has improved pharmacokinetic (PK) and pharmacologic properties compared with entospletinib. We believe that lanraplenib’s differentiated pharmacologic properties support its evaluation as a component of more extended combination dosing regimens with gilteritinib, which is dosed to progression. This lanraplenib clinical trial will include a dose-escalation and an expansion cohort study design. In this trial, the Phase 1b stage will evaluate initial safety, PK and anti-leukemic activity of escalating once-daily doses of lanraplenib in combination with the standard approved dose of gilteritinib in relapsed or refractory FLT3-mutated AML patients. Once a recommended dose is established and pending the data from the Phase 1 stage, we plan to initiate the Phase 2 stage of the trial, with an expansion cohort of approximately 30 patients to further evaluate the safety of lanraplenib and assess its anti-leukemic activity as measured by composite CR rate and duration of response. Based on the data from the first stage of the study, we anticipate deciding whether to proceed with the second stage by mid-2023. Assuming we are successful with the Phase 1b/2 program, we anticipate deciding whether to proceed to Phase 3 in mid-2024. We anticipate making public announcements related to both decisions.
KB-0742
KB-0742, generated from our product engine’s SMM platform is a highly selective, oral CDK9 inhibitor being developed to treat MYC-amplified solid tumors and other trascriptionally addicted tumors. The FDA cleared our IND submission of KB-0742 in December 2020. In February 2021, we initiated our Phase 1/2 clinical trial of KB-0742 to evaluate its safety, PK and PD. Following the dose escalation stage of the clinical trial, we plan to enroll the expansion cohorts at the recommended Phase 2 clinical trial dose and schedule in patients with MYC-amplified solid tumors and other transcriptionally addicted cancers. We reported initial data from the dose escalation stage of the clinical trial in the fourth quarter of 2021 and expect to report the recommended Phase 2 dose and data from the Phase 1 portion of this trial in the fourth quarter of 2022.
Our Team and History
We are led by an experienced executive leadership team with an established track record and decades of scientific and business experience. Collectively, our management team has a track record of obtaining regulatory approval and has successfully commercialized more than 25 therapeutic products across a broad range of disease areas, including but not limited to hematology, oncology, and virology. Norbert Bischofberger, Ph.D., our President and Chief Executive Officer, was previously Chief Scientific Officer and Executive Vice President of Research & Development at Gilead Sciences where he helped build the company over a 28-year tenure and was responsible for the regulatory approval of more than 20 products in therapeutic areas including infectious disease and oncology. Jorge DiMartino, M.D., Ph.D., our Chief Medical Officer and Executive Vice President, Clinical Development, was previously Vice President, Translational Development Oncology at Celgene Corporation, and Group Medical Director at Genentech, Inc. in the Oncology Exploratory Clinical Development group, where he led the early development to proof-of-concept of multiple agents that subsequently received FDA approval. Christopher Dinsmore, Ph.D., our Chief Scientific Officer, was previously an Entrepreneur-in-Residence at Third Rock Ventures, Vice President and Head of Chemistry at Forma Therapeutics, Inc., and a medicinal chemist at Merck & Co., Inc. for 19 years. Barbara Kosacz, J.D., our Chief Operating Officer and General Counsel, was previously head of the global life sciences practice at the international law firm Cooley LLP. She has more than 25 years of experience providing strategic and legal advice to life sciences companies and has structured and negotiated some of the most transformational life sciences transactions in the industry. Yasir Al-Wakeel, BM BCh, our Chief Financial and Head of Corporate Development was previously Chief Financial Officer at Neon Therapeutics, where he played a key role in public and private financings as well as its eventual sale to BioNTech, and at Merrimack Pharmaceuticals. Prior to his industry roles, he held senior roles in equity research at Credit Suisse after practicing medicine in the United Kingdom.
In addition to our management team, we have built a scientific team with deep expertise in transcriptional regulation, computational and chemical biology, drug discovery platform technologies, and computational and medicinal chemistry.
Our company was initially founded by Arie Belldegrun, M.D., FACS, Joshua Kazam, David Tanen and Christopher Wilfong from Two River, LLC (Two River), a life science investment firm that partners with founders to create, finance and operate development-stage biopharmaceutical companies. Two River previously founded Kite Pharma, acquired by Gilead in 2017, and Allogene Therapeutics, Inc. Dr. Belldegrun serves as founding Chair of our board of directors. Dr. Belldegrun is a clinician scientist and biotechnology entrepreneur who also founded Agensys Corporation, acquired by Astellas Pharma, Inc. in 2007, and Cougar Biotechnology, Inc., acquired by Johnson & Johnson in 2009.
Our Pipeline
We have developed a robust clinical pipeline through a combination of internal discovery efforts and focused asset acquisition. The following chart summarizes the current stages of our development programs, including our lead product candidate, entospletinib, as well as lanraplenib KB-0742, and our next anticipated milestones.
We also are executing on robust discovery programs across multiple TRNs, which focus on four cancer types where dysregulated transcription plays a central role: hematologic malignancies, prostate cancer, MYC-driven cancers, and small cell/neuroendocrine cancers. We anticipate submitting an IND for a drug candidate arising from one of these programs in 2023, although we may not be successful in identifying product candidates that can selectively modulate the specific oncogenic TRNs associated with these malignancies.
Entospletinib and Lanraplenib: our SYK Inhibitor Portfolio
Our lead product candidate, entospletinib, is a selective inhibitor targeting SYK, a critical node in a dysregulated TRN within AML defined by persistent high expression of the transcription factors HOX/MEIS. SYK is a non-receptor tyrosine kinase and is an important mediator of immunoreceptor signaling in hematopoietic cells with a clearly established role in both malignant and non-malignant hematologic disease.
SYK is a critical dependency in biomarker-defined subsets of AML patients characterized by persistent high HOX/MEIS expression. Multiple AML driver mutations, including NPM1, MLL (KMT2A) gene rearrangements (MLL-r) and DNMT3A, have been associated with elevation of HOX/MEIS, which increases quantity and activity of SYK as part of an oncogenic TRN. SYK contributes to the leukemia cell state through multiple mechanisms, including direct modulation of downstream growth-promoting transcriptional programs, phosphorylation of FLT3, a known driver of leukemogenic signaling, and participation in a positive feedback loop to MEIS1 that maintains high MEIS1 expression. We believe these multiple oncogenic functions make SYK a compelling therapeutic target and a critical node in the HOX/MEIS TRN.
Our expertise in TRN biology allowed us to recognize SYK as a critical node in the HOX/MEIS TRN, and in July 2020, we acquired a portfolio of selective, orally bioavailable small molecule SYK inhibitors from Gilead. The acquisition included two clinical-stage product candidates:
•Entospletinib – An orally administered SYK inhibitor with high selectivity, dosed twice-daily (BID). Entospletinib has been evaluated in multiple clinical trials in hematologic malignancies, including a three-arm Phase 1b/2 clinical trial in 148 AML patients, both as a monotherapy and in combination with standard of care. In one arm of this study, 53 newly diagnosed AML patients were treated with entospletinib combined with intensive chemotherapy. The trial endpoints of establishing a safe combination dose of entospletinib with intensive chemotherapy and of estimating the rate of CR to this combination were met for this study arm. In addition, a retrospective analysis revealed higher CR rates in subjects with MLL-r and NPM1 mutations than in subjects with neither mutation. Superior overall survival was also observed in patients with high HOX/MEIS mRNA expression as compared to patients with low expression. The results of this retrospective analysis are consistent with the preclinical hypothesis of SYK dependency in HOX/MEIS-driven AML. In the first quarter of 2021, we had an End-of-Phase 2 meeting with the FDA to discuss our proposed design, endpoints and companion diagnostic strategy for our
planned entospletinib registrational trial in patients with NPM1 mutated AML. Based on the discussion and guidance from the meeting, in December 2021 we initiated our registrational Phase 3 AGILITY clinical trial of entospletinib using MRD-negative CR as the primary endpoint in support of potential accelerated approval. We expect to report MRD-negative CR data from this trial in the second half of 2023. In 2021, we initiated similar discussions regarding use of this surrogate primary endpoint with the European Medicines Agency, and received corresponding scientific advice. Based on the scientific advice, we are continuing to pursue this pathway to potential approval in the EU.
•Lanraplenib – A next generation SYK inhibitor with improved PK and pharmacologic properties compared with entospletinib, including once daily (QD) dosing, no food restrictions and compatibility with proton pump inhibitors. Lanraplenib was previously studied in clinical trials that included more than 250 healthy volunteers and patients with autoimmune diseases, establishing an acceptable safety profile. Our preclinical evaluation of lanraplenib has show equivalent anti-leukemic activity in head-to-head comparisons with entospletinib. In July 2021, the FDA cleared our IND submission to begin investigating lanraplenib as a treatment for leukemia. This trial will be the first to assess the compound in patients with cancer. The Phase 1b/2 trial will evaluate lanraplenib in combination with gilteritinib in patients with FLT-3 mutated AML. We expect to initiate the study in the first quarter of 2022.
KB-0742: our CDK9 Inhibitor
KB-0742 was generated from our product engine’s SMM screening platform. KB-0742 is an oral CDK9 inhibitor with a differentiated biochemical selectivity and clinical PK profile. CDK9 is a serine/threonine kinase that forms the catalytic core of the positive transcription elongation factor b (P-TEFb). CDK9 is a global regulator of transcription, and has been recognized as a high-value oncology drug target due to its essential role in maintaining high levels of transcription for oncogenes and short-lived anti-apoptotic proteins.
In February 2021, the first patient was dosed in the first stage of our Phase 1/2 clinical trial to evaluate KB-0742’s safety, PK and PD properties across multiple dose levels. In November 2021, we reported initial results from the first three dose levels of our ongoing dose escalation stage of our Phase 1/2 trial of KB-0742 in patients with solid tumors. The PK analysis showed oral bioavailability and dose-proportional exposure across the first three dose levels, with low to moderate variability between patients. Among the 12 patients treated in the trial, KB-0742 had a terminal half-life of 24 hours, with approximately 2 to 2.5-fold accumulation between Day 1 and Day 10. This long plasma half-life supports our efforts to define a therapeutic window for CDK9 inhibition. Proprietary target engagement assays developed and prospectively validated by us demonstrated dose-dependent reduction of phosphorylation of Ser2 on RNA Polymerase II (pSer2), a direct substrate target of CDK9, as well as reduced expression of CDK9-dependent genes in peripheral blood mononuclear cells from patients at each of the three dose levels. We believe that consistent with the results we observed in our preclinical modeling of KB-0742, further dose escalation is required to reach desired levels of CDK9 inhibition. The nature and severity of the adverse events observed is consistent with what is typically seen among heavily pretreated patients with advanced cancer in Phase 1 trials. We are continuing to enroll and dose escalate patients in this trial.
Our initial development focus for KB-0742 is for potential use in advanced solid tumors with MYC genomic copy number gain (amplification) transcriptionally addicted cancers. MYC is a well-characterized transcription factor and a long-recognized driver of cancer that is dysregulated in a significant proportion of malignancies, including lung, breast, ovarian, and various gastro-intestinal cancers, often as a result of genomic amplification. CDK9 is a critical node in the MYC TRN, acting both as an upstream driver of MYC expression and a downstream co-factor of MYC itself that is required to drive the MYC-dependent oncogenic gene expression program. Preclinical characterization of KB-0742 has demonstrated that MYC genomic amplification is associated with increased tumor sensitivity across multiple histologies, potentially enabling a tissue of origin-agnostic development strategy.
After identifying the recommended Phase 2 dose and dosing schedule, we intend to enroll expansion cohorts of patients with MYC-amplified solid tumors and other transcriptionally addicted tumor types. The subsequent development path to registration will be based on the frequency, magnitude and durability of responses observed in these expansion cohorts.
Discovery Programs
We continually invest in early discovery efforts utilizing our proprietary product engine, with the goal of expanding our pipeline of future product candidates. Our current efforts are focused on four cancer types where dysregulated transcription plays a central role: hematologic malignancies, prostate cancer, MYC-driven cancers, and small cell/neuroendocrine cancers (SCNC). We are developing a deep understanding of the underlying disease biology within these cancer types, engineering robust systems to characterize transcription factor perturbation signatures, and are evaluating multiple potential opportunities for therapeutic intervention through modulation of key TRN components. We select our discovery targets based on scientific, translational and competitive considerations, prioritizing those where dependency has been demonstrated in a defined patient population with high unmet medical need, and where we believe we can design an efficient early clinical translation strategy based upon our understanding of the disease biology.
Our Strategy
Our goal is to become a leading biopharmaceutical company by discovering transformational small molecule modulators of historically challenging targets in cancer and other serious diseases, and then developing and ultimately commercializing those agents using a precision medicine approach for patient populations with high unmet medical need. We intend to do this by continuing to employ our proprietary product engine to discover and develop product candidates. The key elements of our strategy include:
•Rapidly advance our SYK program into and complete registrational clinical trials. We believe that the early clinical data generated in clinical trials of entospletinib, combined with the viability of NPM1 mutations as a genomic marker both for HOX/MEIS-high patient selection and measurement of MRD-negative CR as a primary endpoint, enables an expeditious path to potential accelerated regulatory approval in newly diagnosed AML patients with NPM1 mutations who are eligible for intensive chemotherapy. Based upon the discussion and guidance from our End-of-Phase 2 meeting with FDA, in December 2021 we initiated our registrational Phase 3 AGILITY clinical trial of entospletinib using MRD-negative CR as the primary endpoint. In 2021, we initiated similar discussions regarding use of this surrogate primary endpoint with the European Medicines Agency, and received corresponding scientific advice. Based on the scientific advice, we are continuing to pursue this pathway to potential approval in the EU.We expect to report MRD-negative CR data from our AGILITY trial in the second half of 2023.
•Establish clinical proof of concept for our CDK9 program. In February 2021, the first patient was dosed in the first stage of our Phase 1/2 clinical trial, designed to initially assess the safety, PK and PD profile of KB-0742 in patients with advanced solid tumors, and define an optimal dose and schedule for subsequent signal-seeking expansion cohorts in cancer patients with MYC-amplified solid tumors and other transcriptionally addicted cancers. We reported initial data from the dose escalation stage of the clinical trial in the fourth quarter of 2021, and expect to report the recommended Phase 2 dose and data from the Phase 1 portion of this trial in the fourth quarter of 2022.
•Continue to grow our pipeline of product candidates. We plan to establish a robust pipeline of additional highly differentiated product candidates targeting dysregulated transcription factors and their associated TRNs, particularly through continued investment in our SMM platform, and in our chemical biology, and computational and experimental biology capabilities.
•Selectively enter into strategic collaborations to maximize the potential of and to expand our pipeline. Our product engine has the potential to identify differentiated product candidates addressing a wide variety of diseases with high unmet medical need. We believe this provides us the opportunity to selectively evaluate and, if appropriate, enter into strategic collaborations that leverage our potential future partners’ complementary capabilities to advance and accelerate our development programs or expand our internal discovery efforts, as well as maximize our commercial reach. We also believe we have built a team well suited for the continued identification, evaluation and acquisition of additional product candidates or technologies that complement our core efforts and capabilities.
•Leverage our experienced management team to build a fully-integrated, science-driven biopharmaceutical company addressing high unmet medical needs. Our management team possesses significant expertise across all stages of discovery, translation, late-stage clinical development and commercialization. Collectively, our management team has a track record of obtaining regulatory approval and has successfully commercialized over 25 therapeutic products, including several that have
fundamentally transformed patient outcomes. We plan to progress our product candidates expeditiously through regulatory approval, with the vision of ultimately building a fully-integrated, science-driven biopharmaceutical company.
SYK Inhibitor Product Candidates
Entospletinib and lanraplenib are selective inhibitors of SYK, an important mediator of immunoreceptor signaling in hematopoietic cells with a clearly established role in both malignant and non-malignant hematologic disease.
Entospletinib
Entospletinib has been investigated in multiple clinical trials in patients with hematologic malignancies and has shown encouraging activity in patients with AML who have high expression of HOX/MEIS. Multiple preclinical studies have established a clear dependency between SYK activity and the HOX/MEIS leukemogenic TRN.
We had an End-of-Phase 2 meeting with the FDA in early 2021 to discuss our proposed design, endpoints and companion diagnostic strategy for our entospletinib registrational trial in patients with NPM1 mutated AML. Based upon the discussion and guidance from the meeting with FDA, we initiated our registrational Phase 3 AGILITY clinical trial of entospletinib using measurable residual disease (MRD) negative complete response (CR) as the primary endpoint to support a potential accelerated approval. We initiated the study in December 2021. We expect to report MRD-negative CR data in the second half of 2023. In 2021, we initiated similar discussions regarding use of this surrogate primary endpoint with the European Medicines Agency, and received corresponding scientific advice. Based on the scientific advice, we are continuing to pursue this pathway to potential approval in the EU.
Prior Development of Entospletinib
Since it entered clinical testing in 2013, more than 1,300 people have received entospletinib, including healthy volunteers, patients with renal impairment and inflammatory conditions, and more than 700 patients with hematologic malignancies.
The first clinical trial in healthy volunteers and patients with rheumatoid arthritis (RA) revealed PK consistent with BID dosing and dose dependent SYK inhibition at doses up to 600 mg. Entospletinib was generally well tolerated in healthy volunteers with the most frequently reported adverse events (AEs) being headache, nausea and constipation without any clear relationship to dose level. Mildly increased liver enzymes were observed in some healthy subjects and patients with RA.
The largest group of patients in which entospletinib has been tested have been patients with hematologic malignancies. More than 700 patients, predominantly with B cell malignancies, such as chronic lymphocytic leukemia (CLL), have been treated with entospletinib. Results in CLL were encouraging and consistent with response rates seen for other small molecule inhibitors of B cell receptor signaling such as PI3K delta or Bruton’s Tyrosine Kinase (BTK) inhibitors. An overall response rate (ORR) of 61% and median Progression Free Survival (mPFS) of 13.8 months was observed in 41 patients with relapsed or refractory CLL previously treated with anti-CD20 antibody and alkylating agents. Among 49 patients with CLL that had progressed after treatment with PI3K delta or BTK inhibitors, the ORR was 33% with a mPFS of 5.6 months. The most frequently reported treatment-related AEs, with an incidence greater than 10% in CLL patients, were fatigue, nausea, diarrhea, headache, decreased appetite and fever. AEs attributed to entospletinib of Grade 3 (severe or medically significant but not life-threatening) or greater in at least 5% of patients included neutropenia (four subjects), elevated liver enzymes, hyperbilirubinemia, anemia and hypophosphatemia (two subjects each). Fourteen subjects reported serious AEs, including pneumonia (three subjects), angina pectoris, febrile neutropenia, hypokalemia and sepsis (two subjects each) and acute myocardial infarction, atrial fibrillation, cardiac congestive failure, cellulitis, chest pain, clavicle fracture, dehydration, dyspnea, encephalopathy, epiglottitis, fall, hepatic function abnormal, hepatotoxicity, hypocalcemia, hyponatremia, ischemic cardiomyopathy, leukocytosis, muscular weakness, musculoskeletal chest pain, non-cardiac chest pain, pericardial effusion, pericarditis, pyrexia and rotavirus infection (one subject each), all of which were listed in the applicable investigator brochure describing safety results, without mention of study drug relatedness. Five subjects reported serious AEs assessed by the investigator as related to entospletinib, which included: dyspnea, epiglottitis, febrile neutropenia, hepatic function abnormal, hepatotoxicity and pneumonia. Overall, entospletinib was well-tolerated by CLL patients in these clinical trials. We believe this observed anti-leukemic activity may warrant further investigation in CLL in combination with other agents.
Entospletinib has also been tested in a Phase 1b/2 clinical trial in 148 patients with AML. Early safety studies were conducted in relapsed patients as monotherapy and in combination with intensive chemotherapy and in newly diagnosed elderly patients in combination with HMAs such as azacytidine or decitabine. Aside from the AEs typical of the disease and intensive chemotherapy, such as cytopenias and fever, the main AEs attributable to entospletinib included diarrhea, nausea, and febrile neutropenia. These clinical trials revealed encouraging activity in a subset of patients with AML who have high HOX/MEIS expression, described in greater detail below.
Therapeutic Rationale and Clinical Data in HOX/MEIS-High AML
AML is one of the most common forms of acute leukemia in adults. Despite multiple recent drug approvals, the disease still bears a poor prognosis with less than 30% of patients surviving five years from diagnosis. Although the median age at diagnosis is 67, only younger, typically less than 65 years old, and fitter patients are eligible for intensive chemotherapy, involving seven days treatment with cytarabine and three days treatment with an anthracycline drug such as daunorubicin or idarubicin. Approximately 60% to 70% of these patients achieve CR, but most will experience disease relapse in less than 18 months. Among patients who achieve CR but remain positive for MRD, remissions are often particularly short-lived. For older and less fit patients, prognosis is even worse. Therapeutic options for these patients have historically been limited to palliative treatment with HMAs with CR rates of approximately 30% followed by relapse within a matter of months in a majority of responding patients. The recent approval of the BCL-2 inhibitor venetoclax in combination with HMAs has improved the response rates in older AML patients but relapse free survival remains unacceptably short. There is a clear need for additional therapies to drive improved outcomes in AML, especially agents that improve the MRD-negative CR rate and durability of response in a frontline setting.
SYK activates several aberrant signaling pathways in AML to promote leukemic cell survival and proliferation. SYK is a particularly critical dependency in HOX/MEIS high AML. HOX/MEIS is overexpressed in a significant subset of AML patients. HOXA9 and MEIS1 are transcription factors that work together to drive a gene expression program in primitive myeloid cells. As these cells normally mature, expression of these transcription factors is down-regulated.
Multiple AML driver mutations including NPM1, MLL-r and DNMT3A mutations have been associated with a failure to down-regulate HOX/MEIS as shown in the figure below. This figure is based on our internal analysis of genomic and transcriptomic data from over 400 AML patient samples obtained through the Leukemia and Lymphoma Society’s “Beat AML” program. The figure below depicts mRNA levels for either the HOXA9 or MEIS1 genes across the common AML driver mutations NPM1 (left), MLL-r (center), and DNMT3A (right). For each AML driver mutation, HOXA9 and MEIS1 mRNA levels are shown for either patients that are wildtype for that mutation (grey boxes) or mutated (blue boxes). For each cohort (wild type or mutant), outliers are defined as those patients with mRNA levels exceeding 1.5x the interquartile range (IQR). In all cases, AML driver mutations are associated with increased mRNA levels of HOXA9 and MEIS1 that are consistent with a failure to down-regulate HOX/MEIS expression and are considered statistically significant by a two-sided Mann-Whitney-Wilcoxon test. Failure to down-regulate HOX/MEIS expression locks in the abnormal undifferentiated transcriptional program that defines AML.
AML Driver Mutations and mRNA Expression Levels of HOXA9/MEIS1
Recent publications show that elevated HOX/MEIS results in increased quantity and activity of SYK as part of an oncogenic TRN. SYK contributes to the leukemia cell state by modulating downstream transcriptional programs including genes that promote cytokine independent growth. In addition, SYK promotes leukemia indirectly through phosphorylation of FLT3, a known driver of leukemogenic signaling. Finally, SYK contributes to the stability of the HOX/MEIS TRN through a positive feedback loop to MEIS1 that maintains MEIS1 elevation.
SYK and HOX/MEIS Oncogenic Feedback Loop
Independent of these publications, the Beat AML program tested genomically characterized bone marrow specimens from 572 AML patients in vitro for sensitivity to 122 small molecule drugs or compounds including entospletinib. Our internal analysis of the raw data from this screening program is shown in the figure below, which plots the average difference in area under curve (AUC) drug response between mutant and wild-type on the x-axis and the false discovery rate (FDR) corrected Q value (determined using a two-sided Student’s t-test from a linear model fit) on the y-axis. Sensitivity to entospletinib correlated, with high statistical significance, with the presence of NPM1 mutations alone (FDR < 0.001) or in combination with FLT3 (FDR < 0.0001) or DNMT3A mutations (FDR < 0.01). We believe these multiple oncogenic functions make SYK a compelling therapeutic target and a critical node in the HOX/MEIS TRN.

From July 2015 to February 2019, Gilead investigated the use of entospletinib in a Phase 1b/2 clinical trial enrolling 148 AML patients in the United States, Canada and Germany. Patients were enrolled into one of three arms:
•Arm A: previously untreated, fit AML patients treated with entospletinib monotherapy followed by combination with intensive chemotherapy;
•Arm B: previously untreated elderly or unfit patients treated with entospletinib monotherapy followed by combination therapy with entospletinib and HMA; and
•Arm C: relapsed or refractory AML patients or patients with MLL-r treated with entospletinib monotherapy only.
Dose limiting toxicity was not encountered during monotherapy or combination dose escalation but a dose of 400 mg BID was selected for further expansion in Phase 2 clinical trials based on data suggesting no significant additional target engagement above this dose. Drug-related AEs were primarily febrile neutropenia, maculopapular rash and gastrointestinal, such as nausea, diarrhea, and constipation.
A total of 53 patients were enrolled in Arm A. Of 10 MLL-r patients enrolled, one achieved a CR during the 14-day entospletinib monotherapy window and nine were in CR at the end of combination induction. Across all 53 patients, the CR rate at the end of combination entospletinib and intensive chemotherapy induction was 70%, which is in line with historical CR rates for intensive chemotherapy. A retrospective biomarker analysis of Arm A explored the hypothesis that patients with high HOX/MEIS mRNA are more likely to benefit from the addition of entospletinib to intensive chemotherapy. This retrospective analysis revealed that CR rates in the genetic subsets associated with high HOX/MEIS expression, NPM1 mutations and MLL-r, were 87% (13 out of 15) and 90% (9 out of 10) respectively, compared to 54% (15 out of 28) in patients with neither mutation. Historical CR rates of 56% to 68% with intensive chemotherapy alone have been reported for MLL-r patients. For patients with NPM1 mutations, historical CR rates with intensive chemotherapy alone have ranged from 66% to 87% depending on age and cytogenetics. Age greater than 60 and adverse cytogenetics are associated with the lower end of this range. The subjects enrolled in this study had a median age of 60, and six of the 15 NPM1 mutated patients had secondary AML associated with adverse cytogenetics. The difference between the combined CR rates for the NPM1 and MLL-r groups and the NPM1/MLL wild type groups is statistically significant with a p value of 0.004 (Z-test). HOX/MEIS gene expression was evaluated for 34 patients in whom baseline samples were available for analysis. This analysis revealed that entospletinib-treated patients with high HOX/MEIS mRNA levels (determined as those above the median level of expression) experienced superior overall survival (OS) with a hazard ratio of 0.32 (95% confidence interval 0.1 – 0.997, P = 0.038, log rank test) when compared to those with low HOX/MEIS mRNA levels (determined as those below the median level of expression).
Entospletinib Phase 2 Clinical Trial Data Showed Activity in Defined AML Subsets
The 51 patients enrolled in Arm B had an overall CR rate of 26% with the combination of entospletinib and HMA, which is in line with the historical CR rate for HMA alone. Only two subjects with MLL-r were enrolled in this Arm and exploratory biomarker analyses were not conducted.
Arm C examined entospletinib monotherapy in 13 subjects with relapsed or refractory (R/R) AML with MLL-r, six subjects with R/R AML with wild type MLL and nine newly diagnosed subjects with AML who refused intensive chemotherapy or HMA. Two out of 13 R/R MLL-r subjects in Arm C achieved CRs with entospletinib monotherapy, consistent with the biological hypothesis.
We believe that the retrospective analyses of these clinical data from subjects in the genetic subsets associated with high HOX/MEIS expression, along with the demonstrated biological rationale and our analysis of the Beat AML entospletinib sensitivity data, strongly support the dependency between SYK and HOX/MEIS and provide encouraging evidence of the potential for SYK inhibition to significantly improve upon standard of care for AML patients with elevated HOX/MEIS.
Entospletinib for Patients with AML with NPM1 Mutations
We are developing our lead SYK inhibitor, entospletinib, in combination with intensive chemotherapy in newly diagnosed patients with AML who have NPM1 mutations. While we do not have randomized data showing that the CR rates for newly-diagnosed AML patients with NPM1 mutations treated with entospletinib and intensive chemotherapy are superior to those that would be seen if treating this population with intensive chemotherapy alone, the results from the Gilead-sponsored Phase 1b/2 study suggest that patients with high HOX/MEIS expression respond better to the combination of entospletinib and chemotherapy than patients without this feature. NPM1 mutation is an attractive biomarker for patient selection due to its predictive value of high HOX/MEIS, utility in patient screening and suitability for assessment of MRD.
Predictive Value. Although MLL-r and DNMT3A mutations have higher than average HOX/MEIS expression, NPM1 mutations are the most consistent genetic driver and predictive marker of high HOX/MEIS, as discussed above. Prior to joining our company, our Senior Vice President of Biology was part of the academic team that revealed the mechanistic basis for this association. Based on these considerations, we believe that focusing initially on a more homogeneous group of AML patients defined by a single mutation, NPM1, provides the highest probability of success.
Screening Efficiency. NPM1 mutations are common in AML, reportedly presenting in approximately one-third of adult AML patients. Further, NPM1 mutation status is already routinely assessed in AML patients as part of standard diagnostic workup in the clinic, which we believe will help facilitate clinical trial enrollment and streamline the process for developing and validating a companion diagnostic.
MRD Assessment. Because NPM1 mutation is a genomic marker that can be detected with very high sensitivity using digital Polymerase Chain Reaction or next generation sequencing approaches, we believe NPM1 mutation is an ideal biomarker for MRD assessment. Regulatory approvals on the basis of MRD status have been granted in acute lymphocytic leukemia and CLL, and a growing body of evidence has demonstrated that MRD status post-treatment is a strong predictor of overall survival in AML. We believe that the early clinical data generated by entospletinib, combined with the viability of NPM1 mutation as a genomic marker both for HOX/MEIS-high patient selection and measurement of MRD-negative CR as a surrogate primary endpoint, may enable accelerated regulatory approval of entospletinib in newly diagnosed AML patients with NPM1 mutations.
We had an End-of-Phase 2 meeting with the FDA in early 2021, and we are engaging in similar discussions with European regulatory authorities, to discuss our proposed design, endpoints and companion diagnostic strategy for our planned entospletinib registrational trial in patients with NPM1 mutated AML. Based on discussions with FDA, we initiated our randomized, double-blinded, placebo-controlled registrational Phase 3 clinical trial of entospletinib in combination with intensive chemotherapy in approximately 180 newly diagnosed NPM1-mutated AML patients in December 2021. NPM1 mutation status for enrollment in the trial will be assessed at a central laboratory using a PCR-based assay. We are working with our third-party diagnostic partner to complete the validation of the assay necessary to meet regulatory requirements for a companion diagnostic in parallel with the conduct of the clinical trial. Patients are randomized to receive standard of care intensive chemotherapy in combination with twice-daily entospletinib or a placebo. MRD is assessed in patients who achieve a CR after two cycles of chemotherapy. These patients then go on to receive consolidation therapy with cytarabine and entospletinib or placebo as per their randomization assignment. MRD-negative CR in the intent-to-treat population is the proposed primary endpoint for accelerated approval. Patients will remain in the clinical trial in order to capture event-free and overall survival clinical data.
Our Next Generation SYK Inhibitor Product Candidate: Lanraplenib
Lanraplenib is a SYK inhibitor previously developed by Gilead for autoimmune indications, and has been evaluated in multiple Phase 2 clinical trials in more than 250 patients including health volunteers and patients with autoimmune disease. Lanraplenib has exhibited improved PK properties compared with entospletinib, including an improved half-life, which is compatible with QD dosing among other benefits.
Preclinical modeling suggests that dose levels selected for Phase 2 clinical trials of lanraplenib in autoimmune disease resulted in lower SYK target engagement compared to the dose of entospletinib used in hematologic malignancies. We believe that a higher dose of lanraplenib resulting in equivalent SYK target engagement achieved with entospletinib may create an opportunity to develop lanraplenib in oncology and other indications. Based on our detailed preclinical evaluation of lanraplenib, which showed equivalent anti-leukemic activity in
head-to-head comparisons with entospletinib in various AML models, we are moving forward with a Phase 1b/2 trial, which we anticipate will begin in the first quarter of 2022. and which will evaluate lanraplenib in combination with gilteritinib in patients with relapsed or refractory FLT3-mutated AML.
KB-0742: Our Investigational CDK9 Inhibitor
KB-0742 is an oral CDK9 inhibitor with a differentiated selectivity profile. CDK9 is a global regulator of transcription and a critical node in the oncogenic TRN resulting from MYC overexpression. While CDK9 is a required component of transcriptional machinery for many genes across the genome, certain tumors are “transcriptionally addicted,” meaning that they require a higher level of transcription than normal cells in order to survive.
KB-0742 was internally optimized from an SMM hit and we believe it possesses differentiated selectivity for CDK9 among other attractive pharmacologic properties. While several other compounds targeting CDK9 are being clinically investigated for the treatment of cancer, their published biochemical selectivity profiles indicate the potential for cross-reactivity to cell cycle CDKs at clinical exposures. We believe this may contribute to the toxicity and limited therapeutic index observed with these agents and explain why in general they have not advanced to later-stage clinical trials.
The FDA cleared our IND submission of KB-0742 in December 2020. In February 2021, we initiated our Phase 1/2 clinical trial of KB-0742 to evaluate its safety, PK and PD. Following the dose escalation stage of the clinical trial, we plan to enroll the expansion cohorts at the recommended Phase 2 clinical trial dose and schedule in patients with MYC-amplified solid tumors and pother transcriptionally addicted cancers. We reported initial data from the dose escalation stage of the clinical trial in the fourth quarter of 2021 and expect to report the recommended Phase 2 dose and data from the Phase 1 portion of this trial in the fourth quarter of 2022.
Therapeutic Rationale in MYC-amplified tumors
MYC family transcription factors (MYC, MYCN and MYCL) are master regulators of cell growth, proliferation, differentiation and metabolism, and are among the most frequently dysregulated targets in malignancies. While MYC can be up-regulated through various mechanisms and participates in many oncogenic TRNs, we believe that MYC amplification is one of the clearest markers of transcriptional addiction. MYC amplification appears frequently in many common tumor types and is associated with aggressive disease.
Percentage of Tumors in the National Cancer Institute’s the Cancer Genome Atlas (TCGA) Dataset With Copy Number Gains of MYC, MYCN or MYCL
We believe that CDK9 is an attractive therapeutic target in transcriptionally addicted cancers, and specifically MYC-amplified solid tumors, due to its essential role in transcriptional elongation. MYC is critically dependent on CDK9 in order to drive transcription of downstream target genes and effect the oncogenic program. Additionally, a high rate of transcription is required to maintain elevated MYC protein levels, which creates an additional upstream dependency on large quantities of CDK9. These upstream and downstream dependencies are particularly acute in tumors with MYC genomic amplification, as these cells are addicted to high levels of MYC.
MYC Upstream and Downstream Regulation