Chinook Therapeutics (KDNY) 424B5 Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-255099

The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission and is effective. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and they are not soliciting an offer to buy these securities in any state or other jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED NOVEMBER 8, 2021

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus dated April 14, 2021)

6,000,000 Shares

CHINOOK THERAPEUTICS, INC.

Common Stock

We are offering 6,000,000 shares of our common stock, $0.0001 par value per share, in this offering.

Our common stock is quoted on the Nasdaq Global Market under the symbol “KDNY.” On November 5, 2021, the last reported sales price of our common stock on the Nasdaq Global Market was $15.96 per share. The final public offering price will be determined through negotiation between us and the underwriters in the offering and the recent market price used throughout this prospectus may not be indicative of the final offering price.

We are a “smaller reporting company” as defined under the federal securities laws and are subject to reduced public company reporting requirements.

Investing in our common stock involves a high degree of risk. See “Risk Factors” on page S-5 of this prospectus supplement, page 5 of the prospectus and the documents incorporated by reference herein and therein.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

	PER SHARE	TOTAL
Public offering price	$	$
Underwriting discount and commissions (1)	$	$
Proceeds to Chinook Therapeutics, Inc. (before expenses)	$	$

(1) See “Underwriting” for a description of the compensation payable to the underwriters.

We have granted the underwriters an option for a period of 30 days from the date of this prospectus supplement to purchase up to an additional 900,000 shares of our common stock. If the underwriters exercise their option in full, the total underwriting discounts and commissions payable by us will be $        and the total proceeds to us, before expenses, will be $        .

Delivery of the shares of common stock is expected to be made on or about                , 2021.

Joint Book-Running Managers

SVB Leerink Evercore ISI

Lead Managers

Oppenheimer & Co. Wedbush PacGrow H.C. Wainwright & Co.

Prospectus Supplement dated November    , 2021

TABLE OF CONTENTS

Prospectus Supplement

	PAGE
ABOUT THIS PROSPECTUS SUPPLEMENT		S-ii
PROSPECTUS SUPPLEMENT SUMMARY		S-1
THE OFFERING		S-3
RISK FACTORS		S-5
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		S-7
USE OF PROCEEDS		S-9
DILUTION		S-10
UNDERWRITING		S-12
LEGAL MATTERS		S-17
EXPERTS		S-17
WHERE YOU CAN FIND MORE INFORMATION		S-18
INCORPORATION OF DOCUMENTS BY REFERENCE		S-19

Prospectus

	PAGE
ABOUT THIS PROSPECTUS		1
PROSPECTUS SUMMARY		2
RISK FACTORS		5
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		6
WHERE YOU CAN FIND MORE INFORMATION		7
INCORPORATION OF INFORMATION BY REFERENCE		8
PLAN OF DISTRIBUTION		9
DESCRIPTION OF CAPITAL STOCK		11
DESCRIPTION OF DEBT SECURITIES		14
DESCRIPTION OF WARRANTS		21
DESCRIPTION OF SUBSCRIPTION RIGHTS		23
DESCRIPTION OF UNITS		24
LEGAL MATTERS		25
EXPERTS		26

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ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying prospectus dated April 14, 2021, are part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”), utilizing a “shelf” registration process. This prospectus supplement and the accompanying prospectus relate to the offer by us of shares of our common stock to certain investors. We provide information to you about this offering of shares of our common stock in two separate documents that are bound together: (1) this prospectus supplement, including the documents incorporated by reference herein, which describes the specific details regarding this offering; and (2) the accompanying prospectus, including the documents incorporated by reference therein, which provides general information, some of which may not apply to this offering. Generally, when we refer to this “prospectus,” we are referring to both documents combined. Under this shelf registration process, we may from time to time sell shares of our common stock having an aggregate offering price of up to $275,000,000 under the accompanying prospectus at prices and on terms to be determined by market conditions at the time of the offering.

Before buying any of the common stock that we are offering, we urge you to carefully read this prospectus supplement, the accompanying prospectus and any free writing prospectus and all of the information incorporated by reference herein and therein, as well as the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Documents by Reference.” These documents contain important information that you should consider when making your investment decision.

To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or any document incorporated by reference herein filed prior to the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date (for example, a document incorporated by reference in this prospectus supplement), the statement in the document having the later date modifies or supersedes the earlier statement.

Neither we nor the underwriters have authorized anyone to provide you with any information or to make any representation, other than those contained or incorporated by reference in this prospectus supplement and the accompanying prospectus or in any free writing prospectus prepared by us or on our behalf or to which we have referred you. Neither we nor the underwriters take any responsibility for, and provide no assurance as to the reliability of, any other information that others may give you. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus, the documents incorporated by reference in this prospectus supplement and the accompanying prospectus, and any free writing prospectus is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates.

We are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the offering of the common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the common stock and the distribution of this prospectus supplement outside the United States. This prospectus supplement does not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

Unless the context indicates otherwise, as used in this prospectus supplement, the terms “Chinook,” “Chinook Therapeutics,” the “Company,” “we,” “us,” and “our” refer to Chinook Therapeutics, Inc., a Delaware corporation, and its subsidiaries, taken as a whole, unless otherwise noted. The mark “Chinook Therapeutics, Inc.”, the Chinook Therapeutics logo and all product candidate names are our common law trademarks. Solely

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for convenience, the trademarks and tradenames referred to in this prospectus supplement appear without the ^® and ^™ symbols, but those references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights, or the right of the applicable licensor to these trademarks and tradenames. We do not intend our use or display of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, these other companies.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights information contained in other parts of in this prospectus supplement and the accompanying prospectus, or incorporated by reference in this prospectus supplement from the filings with the SEC listed below under the heading “Incorporation of Information by Reference.” It does not contain all of the information you should consider before making an investment decision. Before you decide to invest in our common stock, you should carefully read the entire prospectus supplement and the accompanying prospectus, including the risk factors and the financial statements and related notes included or incorporated by reference herein and therein. See “Cautionary Note Regarding Forward-Looking Statements.”

Our Company

We are a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing precision medicines for kidney diseases. Our pipeline is focused on rare, severe chronic kidney diseases with well-defined clinical pathways.

Our lead clinical program is atrasentan, an endothelin A receptor antagonist that we in-licensed from AbbVie in late 2019. In March 2021 we initiated the phase 3 ALIGN trial of atrasentan for IgAN, and in April 2021 we initiated the phase 2 AFFINITY basket trial for proteinuric glomerular diseases. We anticipate reporting data from the IgAN cohort of our AFFINITY trial in the first half of 2022 and data from additional cohorts from other glomerular diseases in the second half of 2022. We anticipate reporting data for the primary proteinuria endpoint in the ALIGN trial in 2023.

Our second product candidate, BION-1301, is an anti-APRIL monoclonal antibody also in development for patients with IgAN and we presented results from the ongoing phase 1/2 trial at the American Society of Nephrology (ASN) Kidney Week 2021 in November. The data presented at the conference demonstrate that BION-1301 was generally well-tolerated to date in patients with IgAN, with no serious adverse events or treatment discontinuations due to adverse events. The pharmacokinetics of BION-1301 observed in patients with IgAN are consistent with those previously reported in healthy volunteers and are sufficient to drive rapid and sustained reductions in free APRIL levels. BION-1301 has durably reduced Gd-IgA1, IgA, IgM, and to a lesser extent, IgG levels in patients with IgAN. BION-1301 demonstrated a greater than fifty percent (50%) mean reduction in 24-hour proteinuria (UPCR) in patients with IgAN after three (n=6) to six months (n=4) of treatment, a clinically meaningful mean reduction in UPCR.

We are also advancing our third program, CHK-336, which is currently in IND-enabling studies, towards an expected start of a phase 1 clinical trial in healthy volunteers in the first half of 2022. We are developing CHK-336 for the treatment of primary hyperoxaluria, or PH, as well as secondary hyperoxaluria and idiopathic kidney stone formation. In addition, we are conducting research programs in several other rare, severe chronic kidney diseases.

We seek to build our pipeline by leveraging insights from kidney single cell RNA sequencing, human-derived organoids and new translational models, to discover and develop therapeutic candidates with mechanisms of action targeted against key kidney disease pathways. To support these efforts, we have entered into a strategic collaboration with Evotec SE, or Evotec, to jointly identify, characterize and validate novel mechanisms and discover precision medicines for lupus nephritis, IgAN, polycystic kidney disease, or PKD, and other primary glomerular diseases. The collaboration will also involve further characterization of pathways and patient stratification strategies for programs currently in Chinook’s clinical and preclinical pipeline. In addition, although we plan to maintain commercial rights for atrasentan and BION-1301 in North America and possibly Europe, we are evaluating Asian partnering opportunities, with discussions ongoing to establish a joint venture structure in China and related territories. With a higher incidence and prevalence of IgAN in the Asian population, there is a large unmet medical need and we believe it is important to have a strong presence locally

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that may allow us to accelerate our clinical development programs and maximize the commercial potential of atrasentan and BION-1301 in that region.

Our approach to precision medicines leverages recent advances in identifying targeted kidney therapies linked to mechanistic biomarkers by the application of systems biology approaches in nephrology. The application of systems biology to nephrology has advanced over the past decade through the study of multiple patient groups across a wide variety of kidney diseases and their associated multilevel data sets, including genome, transcriptome, proteome, metabolome, pathology and prospective long-term clinical characteristics and outcomes. A key objective of these investigations is to define kidney diseases in molecular terms to drive the development of targeted treatments. We believe we are well-positioned to exploit the insights provided into the key molecular drivers and classifiers of kidney diseases by the application of these systems biology tools to nephrology. Our strategy is to use these mechanistic insights to select compelling drug targets and deliver novel and differentiated product candidates for rare and severe kidney diseases with high unmet medical need.

Corporate Information

We were incorporated in California as Oncologic, Inc. in 2000. In 2008, we merged with Triton BioSystems, Inc. and subsequently changed our name to Aduro Biotech, Inc., or Aduro, in 2009. In June 2011, we reincorporated as a Delaware corporation. On October 5, 2020 Aduro completed its acquisition of Chinook Therapeutics U.S., Inc., or Private Chinook, pursuant to the terms of a merger agreement dated as of June 1, 2020, as amended on August 17, 2020, by which a wholly owned subsidiary of Aduro merged with and into Private Chinook, with Private Chinook continuing as a wholly owned subsidiary of Aduro, or the Merger. Immediately following the Merger, Aduro changed its name to “Chinook Therapeutics, Inc.” and the business conducted by Private Chinook became the primary business conducted by the Company.

We are incorporated in the State of Delaware. Our principal executive offices are located at 400 Fairview Ave North, 9^th Floor, Seattle, WA, and our telephone number is (206) 485-7051. Our website address is www.chinooktx.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus supplement. We have included our website address in this prospectus supplement solely as an inactive textual reference.

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THE OFFERING

Common stock offered by us	6,000,000 shares
Option to purchase additional shares	We have granted to the underwriters an option for a period of 30 days to purchase up to additional 900,000 shares of our common stock.
Common stock to be outstanding immediately following this offering	50,830,005 shares (or 51,730,005 shares if the underwriters exercise their option to purchase additional shares of our common stock)
Use of proceeds	We currently intend to use the net proceeds of this offering primarily to advance the Phase 3 ALIGN trial of atrasentan in patients with IgA nephropathy (IgAN) and the Phase 2 AFFINITY basket trial of atrasentan in patients with proteinuric glomerular diseases, initiate later-stage clinical development of BION-1301 for IgAN, move forward the development of CHK-336 for hyperoxalurias and continue progress on research and discovery programs. The remainder of the net proceeds, if any, will be used for general corporate purposes. See “Use of Proceeds” on page S-9 of this prospectus supplement.
Risk factors	Investing in our common stock involves significant risks. You should read the “Risk Factors” beginning on page S-5 of this prospectus supplement and page 5 of the accompanying prospectus and in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus for a discussion of factors to consider carefully before deciding to invest in shares of our common stock.
Nasdaq Global Market listing	KDNY

The number of shares of our common stock to be outstanding after this offering is based on 44,830,005 shares of our common stock outstanding as of September 30, 2021, and excludes:

• 6,208,863 shares of common stock issuable upon the exercise of options outstanding as of September 30, 2021 at a weighted-average exercise price of $16.20 per share;

• 70,700 shares of common stock issuable upon the exercise of options that were granted after September 30, 2021 under our 2019 Equity Incentive Plan at a weighted average exercise price of $10.74 per share;

• 18,760 shares of common stock issuable upon the exercise of options that were granted after September 30, 2021 under our 2015 Equity Incentive Plan at a weighted average exercise price of $10.74 per share;

• 901,939 shares of common stock issuable upon the vesting of and settlement of restricted stock units, or RSUs outstanding as of September 30, 2021;

• 45,255 shares of common stock issuable upon the vesting of and settlement of RSUs, that were granted after September 30, 2021;

• 165 shares of common stock issuable upon the exercise of warrants outstanding as of September 30, 2021, with a weighted-average exercise price of $0.07 per share; and

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• 1,355,025 additional shares of common stock reserved for future issuance as of September 30, 2021 under our equity incentive plans, consisting of (1) 1,387 shares of common stock reserved for issuance under our 2019 Equity Incentive Plan, (2) 1,353,638 shares of common stock reserved for issuance under our 2015 Equity Incentive Plan and (3) 704,037 shares of common stock reserved for issuance under our 2015 Employee Stock Purchase Plan.

Shares outstanding as of September 30, 2021 include 123,898 shares subject to forfeiture or repurchase.

Except as otherwise indicated, we have presented the information in this prospectus supplement assuming no exercise of outstanding options and no settlement of restricted stock units after September 30, 2021 and no exercise of the underwriters’ option to purchase additional shares of common stock.

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RISK FACTORS

An investment in our common stock involves a high degree of risk. Before deciding whether to invest in our common stock, you should consider carefully the risks described below and the risks, uncertainties and assumptions discussed in our Quarterly Report on Form 10-Q for the period ended September 30, 2021, which is incorporated by reference in this prospectus supplement and the accompanying prospectus in its entirety, as well as any amendment or update to our risk factors reflected in subsequent filings with the SEC, together with other information in this prospectus supplement, the accompanying prospectus, and the information and documents incorporated by reference that we have authorized for use in connection with this offering. The risks and uncertainties described below and incorporated by reference herein are not the only ones we face. Additionally, to the extent the ongoing COVID-19 pandemic adversely affects our business and financial results, it may also have the effect of heightening many of the other risks incorporated by reference or set forth below. Additional risks and uncertainties that we are unaware of or that we deem immaterial may also become important factors that adversely affect our business. If any of these risks actually occur, our business, financial condition, results of operations or cash flows could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment.

Risks Related to This Offering

We have broad discretion in the use of the net proceeds from this offering and may not use them effectively.

Our management has broad discretion in the application of the net proceeds from this offering, and you will not have the opportunity as part of your investment decision to assess whether the net proceeds are being used appropriately. Our management could spend the net proceeds from this offering in ways that do not improve our results of operations or enhance the value of our common stock. The failure by our management to apply these funds effectively could result in financial losses that could have a material adverse effect on our business, cause the price of our common stock to decline and delay the development of our product candidates. Pending their use, we may invest the net proceeds from this offering in a manner that does not produce income or that loses value. For more information, see “Use of Proceeds” for the intended uses of proceeds from this offering.

If you purchase shares of common stock sold in this offering, you will incur immediate and substantial dilution.

If you purchase shares of our common stock in this offering, you will experience substantial and immediate dilution in the as adjusted net tangible book value per share as of September 30, 2021, based on the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021, because the price that you pay will be substantially greater than the as adjusted net tangible book value per share of the common stock that you acquire. This dilution is due in large part to the fact that certain of our earlier investors paid substantially less than the offering price when they purchased shares of our capital stock. You will experience additional dilution upon exercise of the outstanding stock options and other equity awards that may be granted under our equity incentive plans, and when we otherwise issue additional shares of our common stock. For more information, see “Dilution.”

A sale of a substantial number of shares of our common stock may cause the price of our common stock to decline.

Sales of a substantial number of shares of our common stock in the public market, or the perception that these sales might occur, could depress the market price of our common stock and could impair our ability to raise capital through the sale of additional equity securities. Further, we have a number of stock options and restricted stock units outstanding. If a substantial number of shares of common stock underlying these stock options, or any vested restricted stock units, are sold, or if it is perceived that these will be sold in the public market, it could have an adverse impact on the market price of our common stock. We are unable to predict the effect that sales may have on the prevailing market price of our common stock.

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We may raise money through additional public or private offerings of our equity securities or equity-linked securities. For example, in April 2021, we entered into an “at-the-market” program and sales agreement with Leerink SVB and Cantor Fitzgerald & Co., under which we may, from time to time, offer and sell common stock having an aggregate offering value of up to $75.0 million, subject to certain conditions. Any sales of our equity or equity-linked securities could have a material adverse effect on the market price of our common stock.

In connection with this offering, we, and our directors and executive officers have entered into lock-up agreements with the underwriters, for a period of 90 days after the date of this prospectus supplement. The lock-up agreements are subject to various exceptions, and we and our directors and executive officers may be released from the lock-up agreements prior to the expiration of the lock-up period at the sole discretion of the representatives. See “Underwriting.” Upon expiration or earlier release of the lock-up agreements, we and our directors and executive officers may sell shares into the market, which could adversely affect the market price of shares of our common stock.

We also expect that significant additional capital may be needed in the future to continue our planned operations. To raise capital, we may sell common stock, convertible securities or other equity securities in one or more transactions at prices and in a manner we determine from time to time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock.

In addition, we have a significant number of stock options outstanding, and may also choose to issue additional common stock, or securities convertible into or exchangeable for common stock, in the future in connection with a financing, an acquisition, a litigation settlement, employee arrangements or otherwise. In the event that the outstanding options are exercised, or that we make additional issuances of common stock or other convertible or exchangeable securities, you could experience additional dilution. Furthermore, we cannot assure you that we will be able to issue shares or other securities in any other offering at a price per share that is equal to or greater than the price per share paid by investors in this offering, and investors purchasing our securities in the future may have rights superior to investors purchasing shares in this offering.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus, and documents incorporated by reference herein and therein contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements involve a number of risks and uncertainties. We caution readers that any forward-looking statement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statement. These statements are based on current expectations of future events. Such statements include, but are not limited to, statements concerning the following:

• our ability to develop and commercialize our product candidates;

• our ability to use and expand our technologies to build a pipeline of product candidates;

• our ability to obtain and maintain regulatory approval of our product candidates;

• the strength and breadth of our patent portfolio;

• our ability to execute on our corporate strategy;

• the potential for receipt of additional milestone payments;

• our ability to fund our working capital needs;

• our ability to obtain and adequately protect intellectual property rights for our product candidates;

• our continued reliance on third parties for manufacturing our product candidates, conducting our clinical trials and certain research activities;

• our ability to in-license, acquire or invest in complementary businesses, technologies, products or assets to further expand or complement our portfolio of product candidates;

• expected timing of data readouts from and initiation and completion of our clinical trials;

• the timing and availability of results of our clinical trials and those of our collaborators;

• our ability to extend our operating capital;

• the anticipated use of the net proceeds from this offering;

• our anticipated cash runway; and

• other statements that are not historical facts.

You can find many of these statements by looking for words like as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “plan,” “expect” or the negative or plural of these words or similar expressions in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein and any free writing prospectus. We intend that such forward-looking statements be subject to the safe harbors created thereby.

These forward-looking statements are based on the current beliefs and expectations of our management and are subject to significant risks and uncertainties. If underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results may differ materially from current expectations and projections. Factors that might cause such a difference include those discussed in our most recent Annual Report on Form 10-K and subsequent Quarterly Report filings with the SEC, as well as those discussed in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein and any free writing prospectus. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date made.

All subsequent written or oral forward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. We do not undertake any obligation to release publicly any revisions to these forward-looking statements to reflect

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events or circumstances after the date of this prospectus supplement or to reflect the occurrence of unanticipated events, except as may be required under applicable U.S. securities laws. If we do update one or more forward-looking statements, no inference should be drawn that we will make additional updates with respect to those or other forward-looking statement

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USE OF PROCEEDS

We estimate that the net proceeds of this offering, after deducting estimated underwriting discounts and commissions and estimated offering expenses, will be approximately $89.6 million, or $103.1 million if the underwriters’ option to purchase additional shares is exercised in full based on the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021.

Each $1.00 increase or decrease in the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021, would increase or decrease the net proceeds to us from this offering by approximately $5.6 million, assuming the number of shares offered by us, as set forth on the cover page of this prospectus supplement, remains the same, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Similarly, each increase or decrease of 1.0 million shares in the number of shares offered by us would increase or decrease the net proceeds to us from this offering by approximately $15.0 million, assuming that the assumed public offering price remains the same, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. We do not expect that a change in the public offering price or the number of shares by these amounts would have a material effect on our uses of the proceeds from this offering, although it may accelerate the time at which we will need to seek additional capital.

We currently intend to use the net proceeds from this offering, together with our existing cash, cash equivalents and marketable securities to advance the phase 3 ALIGN trial of atrasentan in patients with IgA nephropathy (IgAN) and the phase 2 AFFINITY basket trial of atrasentan in patients with proteinuric glomerular diseases, initiate later-stage clinical development of BION-1301 for IgAN, move forward the development of CHK-336 for hyperoxalurias and continue progress on research and discovery programs. The remainder of the net proceeds, if any, will be used for general corporate purposes. We expect the net proceeds from this offering, together with our existing cash, cash equivalents and marketable securities, and other available sources of cash to be sufficient to fund our operations and clinical development activities into 2024.

The amounts and timing of our actual expenditures will depend on numerous factors, including the progress of our clinical trials and other development efforts and other factors described under “Risk Factors” in this prospectus supplement and the documents incorporated by reference herein, as well as the amount of cash used in our operations. As a result, our management will have broad discretion over the uses of the net proceeds from this offering and investors will be relying on the judgment of our management regarding the application of the proceeds. Pending these uses, we intend to invest the net proceeds in short-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or guaranteed obligations of the U.S. government.

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DILUTION

If you invest in our common stock, your interest will be diluted to the extent of the difference between the price per share you pay in this offering and the net tangible book value per share of our common stock immediately after this offering. Our net tangible book value of our common stock as of September 30, 2021 was approximately $188.3 million, or approximately $4.20 per share of common stock based upon 44,830,005 shares outstanding. Net tangible book value per share is equal to our total tangible assets, less our total liabilities, divided by the total number of shares outstanding as of September 30, 2021.

After giving effect to the sale of shares of our common stock in this offering at the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of September 30, 2021 would have been approximately $277.9 million, or $5.47 per share. This represents an immediate increase in net tangible book value of $1.27 per share to existing stockholders and immediate dilution of $10.49 per share to investors purchasing our common stock in this offering at the public offering price. The following table illustrates this dilution on a per share basis:

Assumed public offering price per share			$	15.96
Net tangible book value per share as of September 30, 2021, before giving effect to this offering	$	4.20
Increase in as adjusted net tangible book value per share attributable to investors in to this offering		1.27
As adjusted net tangible book value per share, after this offering				5.47
Dilution per share to investors purchasing shares in this offering			$	10.49

Each $1.00 increase or decrease in the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021, would increase or decrease, as applicable, the as adjusted net tangible book value per share after this offering by $0.11 per share and the dilution to investors purchasing common stock in this offering by $0.89 per share, assuming the number of shares offered by us, as set forth on the cover page of this prospectus supplement, remains the same, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. An increase of 1.0 million shares in the number of shares offered by us would increase the as adjusted net tangible book value per share after this offering by $0.18 and decrease the dilution per share to new investors participating in this offering by $0.18. A decrease of 1.0 million shares in the number of shares offered by us would decrease the as adjusted net tangible book value per share after this offering by $0.19 and increase the dilution per share to new investors participating in this offering by $0.19, assuming the assumed public offering price of $15.96 per share, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021, remains the same, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

If the underwriters exercise their option to purchase shares of common stock in full, the as adjusted net tangible book value after this offering would be approximately $5.63 per share, representing an increase in net tangible book value of approximately $1.43 per share to existing stockholders and immediate dilution in net tangible book value of approximately $10.33 per share to investors purchasing our common stock in this offering at the assumed public offering price, the last reported sales price of our common stock on the Nasdaq Global Market on November 5, 2021.

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The foregoing tables and calculations are based on 44,830,005 shares of our common stock outstanding as of September 30, 2021, and excludes:

• 6,208,863 shares of common stock issuable upon the exercise of options outstanding as of September 30, 2021 at a weighted-average exercise price of $16.20 per share;

• 70,700 shares of common stock issuable upon the exercise of options that were granted after September 30, 2021 under our 2019 Equity Incentive Plan at a weighted average exercise price of $10.74 per share;

• 18,760 shares of common stock issuable upon the exercise of options that were granted after September 30, 2021 under our 2015 Equity Incentive Plan at a weighted average exercise price of $10.74 per share;

• 901,939 shares of common stock issuable upon the vesting of and settlement of restricted stock units, or RSUs, outstanding as of September 30, 2021;

• 45,255 shares of common stock issuable upon the vesting of and settlement of restricted stock units, or RSUs, that were granted after September 30, 2021;

• 165 shares of common stock issuable upon the exercise of warrants outstanding as of September 30, 2021, with a weighted-average exercise price of $0.07 per share; and

• 1,355,025 additional shares of common stock reserved for future issuance as of September 30, 2021 under our equity incentive plans, consisting of (1) 1,387shares of common stock reserved for issuance under our 2019 Equity Incentive Plan, (2) 1,353,638 shares of common stock reserved for issuance under our 2015 Equity Incentive Plan and (3) 704,037 shares of common stock reserved for issuance under our 2015 Employee Stock Purchase Plan.

Shares outstanding as of September 30, 2021 include 123,898 shares subject to forfeiture or repurchase.

Except as otherwise indicated, we have presented the information in this prospectus supplement assuming no exercise of outstanding options and no settlement of restricted stock units after September 30, 2021 and no exercise of the underwriters’ option to purchase additional shares of common stock.

To the extent that outstanding options are exercised or other shares issued, investors purchasing our common stock in this offering will experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

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UNDERWRITING

SVB Leerink LLC and Evercore Group L.L.C. are acting as representatives of each of the underwriters named below and as joint book-running managers for this offering. Subject to the terms and conditions set forth in the underwriting agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, the number of shares of common stock set forth opposite its name below.

Underwriter	Number of Shares
SVB Leerink LLC
Evercore Group L.L.C
Oppenheimer & Co. Inc.
Wedbush Securities Inc.
H.C. Wainwright & Co., LLC
Total		6,000,000

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the shares sold under the underwriting agreement if any of the shares are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the shares, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the shares, and subject to other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officers’ certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Discounts and Commissions

The representatives have advised us that the underwriters propose initially to offer the shares to the public at the public offering price set forth on the cover page of this prospectus supplement and to dealers at that price less a concession not in excess of $        per share. After the initial offering of the shares, the public offering price, concession or any other term of this offering may be changed by the representatives.

The following table shows the public offering price, underwriting discounts and commissions and proceeds, before expenses, to us. The information assumes either no exercise or full exercise by the underwriters of their option to purchase additional shares of our common stock.

		Total
	Per Share	Without Option	With Option
Public offering price	$	$	$
Underwriting discounts and commissions	$	$	$
Proceeds, before expenses, to us	$	$	$

We estimate expenses payable by us in connection with this offering, other than the underwriting discounts and commissions referred to above, will be approximately $400,000. We also have agreed to reimburse the underwriters for up to $25,000 for their FINRA counsel fee. In accordance with FINRA Rule 5110, this reimbursed fee is deemed underwriting compensation for this offering.

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Option to Purchase Additional Shares

We have granted an option to the underwriters, exercisable for 30 days after the date of this prospectus supplement, to purchase up to 900,000 additional shares at the public offering price, less underwriting discounts and commissions. If the underwriters exercise this option, each underwriter will be obligated, subject to the conditions contained in the underwriting agreement, to purchase a number of additional shares proportionate to that underwriter’s initial amount reflected in the above table.

No Sales of Similar Securities

We, our executive officers and directors have agreed not to sell or transfer any common stock or securities convertible into or exchangeable or exercisable for common stock, for 90 days after the date of this prospectus supplement without first obtaining the written consent of the representatives on behalf of the underwriters, in the case of our directors and officers, and SVB Leerink on behalf of the underwriters in the case of the company. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly:

• offer, pledge, sell or contract to sell any common stock;

• sell any option or contract to purchase any common stock;

• purchase any option or contract to sell any common stock;

• grant any option, right or warrant for the sale of any common stock;

• otherwise dispose of or transfer any common stock;

• request or demand that we file a registration statement related to the common stock; or

• enter into any swap or other agreement or any transaction that transfers, in whole or in part, the economic consequence of ownership of any common stock, whether any such swap, agreement or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.

The lock-up provisions apply to common stock and to securities convertible into or exchangeable or exercisable for common stock. They also apply to common stock owned now or acquired later by the person executing the lock-up agreement or for which the person executing the lock-up agreement later acquires the power of disposition.

Nasdaq Global Market Listing

Our common stock is listed on the Nasdaq Global Market under the symbol “KDNY.”

Price Stabilization, Short Positions and Penalty Bids

Until the distribution of the shares is completed, SEC rules may limit underwriters and selling group members from bidding for and purchasing our common stock. However, the representatives may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price.

In connection with this offering, the underwriters may purchase and sell our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in this offering. “Covered” short sales are sales made in an amount not greater than the underwriters’ option to purchase additional shares described above. The underwriters may close out any covered short position by either exercising their option to purchase additional shares or purchasing shares in the open market. In determining the source of shares to close out the covered short position, the underwriters

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will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which they may purchase shares through the option to purchase additional shares granted to them under the underwriting agreement described above. “Naked” short sales are sales in excess of such option. The underwriters must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of our common stock in the open market after pricing that could adversely affect investors who purchase in this offering. Stabilizing transactions consist of various bids for or purchases of shares of common stock made by the underwriters in the open market prior to the closing of this offering.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Global Market, in the over-the-counter market or otherwise.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our common stock. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Electronic Distribution

In connection with this offering, certain of the underwriters or securities dealers may distribute prospectuses by electronic means, such as e-mail.

Other Relationships

The underwriters and certain of their affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Some of the underwriters and certain of their affiliates may in the future engage in investment banking and other commercial dealings in the ordinary course of business with us and our affiliates, for which they may in the future receive customary fees, commissions and expenses.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Selling Restrictions

Notice to Prospective Investors in the European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant State”), no shares have been offered or will be offered pursuant to the offering to the public in that Relevant State prior to the publication

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of a prospectus in relation to the shares which has been approved by the competent authority in that Relevant State or, where appropriate, approved in another Relevant State and notified to the competent authority in that Relevant State, all in accordance with the Prospectus Regulation, except that shares may be offered to the public in that Relevant State at any time:

A. to any legal entity which is a qualified investor as defined under Article 2 of the Prospectus Regulation;

B. to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation), subject to obtaining the prior consent of the representatives for any such offer; or

C. in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of shares shall require us or any of the representatives to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation.

For the purposes of this provision, the expression an “offer to the public” in relation to any shares in any Relevant State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129, as amended.

Notice to Prospective Investors in the United Kingdom

No shares have been offered or will be offered pursuant to the offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the Shares which has been approved by the Financial Conduct Authority, except that the shares may be offered to the public in the United Kingdom at any time:

A. to any legal entity which is a qualified investor as defined under Article 2 of the UK Prospectus Regulation;

B. to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the representatives for any such offer; or

C. in any other circumstances falling within Section 86 of the Financial Services and Markets Act 2000 (the “FMSA”),

provided that no such offer of the shares shall require us or any representative to publish a prospectus pursuant to Section 85 of the FSMA or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to the shares in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

Notice to Prospective Investors in Canada

The shares may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the shares must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

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Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

S-16

LEGAL MATTERS

The validity of the common stock offered hereby and certain other legal matters in connection with this offering will be passed upon by Fenwick & West LLP, San Francisco, California. Certain legal matters relating to this offering will be passed upon for the underwriters by Latham & Watkins LLP, Menlo Park, California.

EXPERTS

The financial statements incorporated in this prospectus supplement by reference to the Annual Report on Form 10-K for the year ended December 31, 2020 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

S-17

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the shares of common stock offered hereby. This prospectus supplement, which constitutes a part of the registration statement, does not contain all of the information set forth in the registration statement or the exhibits filed therewith. For further information about us and the common stock offered hereby, reference is made to the accompanying prospectus and registration statement of which it is a part and the exhibits filed therewith. Statements contained in this prospectus supplement regarding the contents of any contract or any other document that is filed as an exhibit to the accompanying prospectus and the registration statement of which it is a part are not necessarily complete, and in each instance we refer you to the copy of such contract or other document filed as an exhibit to the registration statement or the exhibits to the reports or other documents incorporated by reference in this prospectus supplement for a copy of such contract or other document.

We are subject to the informational requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act and are required to file annual, quarterly and other reports, proxy statements and other information with the SEC. The SEC maintains a website (http://www.sec.gov) that contains reports, proxy and information statements, and various other information about us. You may also inspect the documents described herein at our principal executive offices, 400 Fairview Ave North, 9th Floor, Seattle, WA, during normal business hours.

Information about us is also available at our website at http://www.chinooktx.com. However, the information on our website is not a part of this prospectus supplement and is not incorporated by reference into this prospectus supplement.

S-18

INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with the SEC, which means that we can disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus supplement and the accompanying prospectus, and information we file later with the SEC will automatically update and supersede this information. A Current Report (or portion thereof) furnished, but not filed, on Form 8-K shall not be incorporated by reference into this prospectus supplement and the accompanying prospectus. We incorporate by reference the documents listed below and any future filings we make with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Exchange Act prior to the termination of any offering of securities made by this prospectus supplement and accompanying prospectus:

(1) Our Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on April 7, 2021;

(2) Our Quarterly Report on Form 10-Q for the quarters ended March 31, 2021, June 30, 2021, and September 30, 2021 filed with the SEC on May  12, 2021, August 12, 2021 and November 8, 2021, respectively;

(3) Our Current Reports on Form 8-K filed on June  9, 2021, and June 21, 2021 (in each case to the extent filed and not furnished);

(4) Our Definitive Proxy Statement on Schedule 14A , filed with the SEC on April 23, 2021 (but only with respect to information required by Part III of our Annual Report on Form 10-K for the year ended December 31, 2020, which information shall update and supersede information included in Part III of our Annual Report on Form 10-K for the year ended December 31, 2020); and

(5) The description of our common stock in our Registration Statement on Form 8-A (No. 001-37245) filed with the SEC on April 10, 2015 under Section 12(b) of the Exchange Act, and including any other amendments or reports filed for the purpose of updating such description.

We will furnish without charge to you, on written or oral request, a copy of any or all of such documents that has been incorporated herein by reference (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into the documents that this prospectus supplement incorporates). Written or oral requests for copies should be directed to Chinook Therapeutics, Inc., Attn: Investor Relations, 400 Fairview Ave North, 9^th Floor, Seattle, WA, telephone number (206) 485-7051. See the section of this prospectus supplement entitled “Where You Can Find More Information” for information concerning how to read and obtain copies of materials that we file with the SEC.

Any statement contained in this prospectus supplement, or in a document all or a portion of which is incorporated by reference, shall be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any document incorporated by reference modifies or supersedes such statement. Any such statement so modified or superseded shall not, except as so modified or superseded, constitute a part of this prospectus supplement.

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PROSPECTUS

$275,000,000

Common Stock, Preferred Stock,

Debt Securities, Warrants, Subscription Rights and Units

From time to time, we may offer up to $275,000,000 aggregate dollar amount of shares of our common stock or preferred stock, debt securities, warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debt securities and/or units consisting of some or all of these securities, in any combination, together or separately, in one or more offerings, in amounts, at prices and on the terms that we will determine at the time of the offering and which will be set forth in a prospectus supplement and any related free writing prospectus. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. The total amount of these securities will have an initial aggregate offering price of up to $275,000,000. You should read this prospectus, the information incorporated, or deemed to be incorporated, by reference in this prospectus, and any applicable prospectus supplement and related free writing prospectus carefully before you invest.

Our common stock is traded on The Nasdaq Global Select Market under the symbol “KDNY.” On April 6, 2021 the last reported sales price for our common stock was $14.83 per share. None of the other securities we may offer are currently traded on any securities exchange. The applicable prospectus supplement and any related free writing prospectus will contain information, where applicable, as to any other listing on The Nasdaq Global Select Market or any securities market or exchange of the securities covered by the prospectus supplement and any related free writing prospectus.

An investment in our securities involves a high degree of risk. You should carefully consider the information under the heading “Risk Factors” beginning on page 5 of this prospectus before investing in our securities.

Common stock, preferred stock, debt securities, warrants, subscription rights and/or units may be sold by us to or through underwriters or dealers, directly to purchasers or through agents designated from time to time. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus. If any underwriters, dealers or agents are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such underwriters or agents and any applicable fees, discounts or commissions, details regarding over-allotment options, if any, and the net proceeds to us will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is April 14, 2021

TABLE OF CONTENTS

	PAGE
ABOUT THIS PROSPECTUS		1
PROSPECTUS SUMMARY		2
RISK FACTORS		5
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		6
WHERE YOU CAN FIND MORE INFORMATION		7
INCORPORATION OF INFORMATION BY REFERENCE		8
PLAN OF DISTRIBUTION		9
DESCRIPTION OF CAPITAL STOCK		11
DESCRIPTION OF DEBT SECURITIES		14
DESCRIPTION OF WARRANTS		21
DESCRIPTION OF SUBSCRIPTION RIGHTS		23
DESCRIPTION OF UNITS		24
LEGAL MATTERS		25
EXPERTS		26

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the United States Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, from time to time, we may sell any combination of the securities described in this prospectus in one or more offerings, up to a total of $275.0 million.

We have provided to you in this prospectus a general description of the securities we may offer. Each time we sell securities under this shelf registration process, we will provide a prospectus supplement that will contain specific information about the terms of the offering. We may also add, update or change in the prospectus supplement any of the information contained in this prospectus. To the extent there is a conflict between the information contained in this prospectus and the prospectus supplement, you should rely on the information in the prospectus supplement; provided that, if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in this prospectus or any prospectus supplement—the statement in the document having the later date modifies or supersedes the earlier statement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

Neither we, nor any agent, underwriter or dealer have authorized anyone to give you any information or to make any representation other than the information and representations contained in or incorporated by reference into this prospectus or any applicable prospectus supplement. We and any agent, underwriter or dealer take no responsibility for, and can provide no assurance as to the reliability of, any other information others may give you. You may not imply from the delivery of this prospectus and any applicable prospectus supplement, nor from a sale made under this prospectus and any applicable prospectus supplement, that our affairs are unchanged since the date of this prospectus and any applicable prospectus supplement or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus and any applicable prospectus supplement or any sale of a security. This prospectus and any applicable prospectus supplement may only be used where it is legal to sell the securities.

THIS PROSPECTUS MAY NOT BE USED TO OFFER AND SELL SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

In this prospectus, unless the context otherwise requires, the terms “Chinook,” “Chinook Therapeutics,” the “Company,” “we,” “us,” and “our” refer to Chinook Therapeutics, Inc., a Delaware corporation.

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PROSPECTUS SUMMARY

This summary highlights information contained in other parts of this prospectus or incorporated by reference in this prospectus from our Annual Report on Form 10-K for the year ended December 31, 2020, and our other filings with the SEC listed below under the heading “Incorporation of Information by Reference.” This summary may not contain all the information that you should consider before investing in securities. You should read the entire prospectus and the information incorporated by reference in this prospectus carefully, including “Risk Factors” and the financial data and related notes and other information incorporated by reference, before making an investment decision. See “Cautionary Note Regarding Forward-Looking Statements.”

Our Company

We are a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing precision medicines for kidney diseases. Our pipeline is focused on rare, severe chronic kidney diseases with well-defined clinical pathways. Our lead clinical program is atrasentan, an endothelin A receptor antagonist that we in-licensed from AbbVie in late 2019. In March 2021 we initiated the phase 3 ALIGN trial of atrasentan for IgAN, and in April 2021 we initiated the phase 2 AFFINITY basket trial for primary glomerular diseases. Our second product candidate, BION-1301, is an anti-APRIL monoclonal antibody also in development for patients with IgAN, and we anticipate presenting interim results from the ongoing phase 1b trial at multiple nephrology conferences in 2021. We are also advancing our third program, CHK-336, which is currently in IND enabling studies, towards an IND submission expected in late 2021 or early 2022 for the treatment of PH. In addition, we are conducting research programs in several other rare, severe chronic kidney diseases. We seek to build our pipeline by leveraging insights in kidney single cell RNA sequencing, human-derived organoids and new translational models, to discover and develop therapeutic candidates with mechanisms of action targeted against key kidney disease pathways. To support these efforts, we have entered into a strategic collaboration with Evotec. Based on Evotec’s proprietary comprehensive molecular datasets from thousands of patients across chronic kidney diseases of multiple underlying etiologies, we and Evotec will jointly identify, characterize and validate novel mechanisms and discover precision medicines for PKD, lupus nephritis, IgA nephropathy and other primary glomerular diseases. The collaboration will also involve further characterization of pathways and patient stratification strategies for programs currently in Chinook’s clinical and preclinical pipeline.

Our approach to precision medicines leverages recent advances in identifying targeted kidney therapies linked to mechanistic biomarkers by the application of systems biology approaches in nephrology.

The application of systems biology to nephrology has advanced over the past decade through the study of multiple patient groups across a wide variety of kidney diseases and their associated multilevel data sets, including genome, transcriptome, proteome, metabolome, pathology and prospective long-term clinical characteristics and outcomes. A key objective of these investigations is to define kidney diseases in molecular terms to drive the development of targeted treatments. We believe we are well-positioned to exploit the insights provided into the key molecular drivers and classifiers of kidney diseases by the application of these systems biology tools to nephrology. Our strategy is to use these mechanistic insights to select compelling drug targets and deliver novel and differentiated product candidates for rare and severe kidney diseases with high unmet medical need.

The Securities We May Offer

With this prospectus, we may offer common stock, preferred stock, debt securities, warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debt securities, and/or units consisting of some or all of these securities in any combination. The aggregate offering price of securities that we offer with this prospectus will not exceed $275.0 million. Each time

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we offer securities with this prospectus, we will provide offerees with a prospectus supplement that will contain the specific terms of the securities being offered. The following is a summary of the securities we may offer with this prospectus.

Common Stock

We may offer shares of our common stock, par value $0.0001 per share.

Preferred Stock

We may offer shares of our preferred stock, par value $0.0001 per share, in one or more series. Our board of directors or a committee designated by the board will determine the dividend, voting, conversion and other rights of the series of shares of preferred stock being offered. Each series of preferred stock will be more fully described in the particular prospectus supplement that will accompany this prospectus, including redemption provisions, rights in the event of our liquidation, dissolution or the winding up, voting rights and rights to convert into common stock.

Debt Securities

We may offer general obligations, which may be secured or unsecured, senior or subordinated and convertible into shares of our common stock or preferred stock. In this prospectus, we refer to the senior debt securities and the subordinated debt securities together as the “debt securities.” Our board of directors will determine the terms of each series of debt securities being offered.

We will issue the debt securities under an indenture between us and a trustee. In this document, we have summarized general features of the debt securities from the indenture. We encourage you to read the indenture, which is an exhibit to the registration statement of which this prospectus is a part.

Warrants

We may offer warrants for the purchase of debt securities, shares of preferred stock or shares of common stock. We may issue warrants independently or together with other securities. Our board of directors will determine the terms of the warrants.

Subscription Rights

We may offer subscription rights for the purchase of common stock, preferred stock or debt securities. We may issue subscription rights independently or together with other securities. Our board of directors will determine the terms of the subscription rights.

Units

We may offer units consisting of some or all of the securities described above, in any combination, including common stock, preferred stock, warrants and/or debt securities. The terms of these units will be set forth in a prospectus supplement. The description of the terms of these units in the related prospectus supplement will not be complete. You should refer to the applicable form of unit and unit agreement for complete information with respect to these units.

* * *

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Company Information

We were incorporated in California as Oncologic, Inc. in 2000. In 2008, we merged with Triton BioSystems, Inc. and subsequently changed our name to Aduro Biotech, Inc., or Aduro, in 2009. In June 2011, we reincorporated as a Delaware corporation. On October 5, 2020 Aduro completed its acquisition of Chinook Therapeutics U.S., Inc., or Private Chinook, pursuant to the terms of a merger agreement dated as of June 1, 2020, as amended on August 17, 2020, by which a wholly owned subsidiary of Aduro merged with and into Private Chinook, with Private Chinook continuing as a wholly owned subsidiary of Aduro, or the Merger. Immediately following the Merger, Aduro changed its name to “Chinook Therapeutics, Inc.” and the business conducted by Private Chinook became the primary business conducted by the Company.

4

RISK FACTORS

An investment in our securities involves a high degree of risk. The prospectus supplement applicable to each offering of securities will contain a discussion of the risks applicable to an investment in our securities. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under Part II, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K for the year ended December 31, 2020, which is incorporated herein by reference, and may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations.

5

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and documents incorporated herein by reference contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements involve a number of risks and uncertainties. We caution readers that any forward-looking statement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statement. These statements are based on current expectations of future events.

Such statements include, but are not limited to, statements concerning the following:

• the potential of our technologies and our ability to execute on our corporate strategy;

• our ability to fund our working capital needs;

• our ability to develop and commercialize our product candidates;

• our ability to use and expand our technologies to build a pipeline of product candidates;

• our ability to obtain and maintain regulatory approval of our product candidates;

• the strength and breadth of our patent portfolio;

• the potential for receipt of additional milestone payments;

• our ability to obtain and adequately protect intellectual property rights for our product candidates;

• our continued reliance on third parties for manufacturing our product candidates, conducting our clinical trials and certain research activities;

• our ability to in-license, acquire or invest in complementary businesses, technologies, products or assets to further expand or complement our portfolio of product candidates;

• expected timing of our clinical trials;

• the timing and availability of results of our clinical trials and those of our collaborators;

• our ability to extend our operating capital; and

• other statements that are not historical facts.

In some cases you can identify these statements by forward-looking words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “plan,” “expect” or the negative or plural of these words or similar expressions, in documents incorporated by reference into this prospectus or any free writing prospectus. We intend that such forward-looking statements be subject to the safe harbors created thereby.

These forward-looking statements are based on the current beliefs and expectations of our management and are subject to significant risks and uncertainties. If underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results may differ materially from current expectations and projections. Factors that might cause such a difference include those discussed in Part II, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as well as those discussed in this prospectus, the documents incorporated by reference into this prospectus and any free writing prospectus. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this prospectus or, in the case of documents referred to or incorporated by reference, the date of those documents.

All subsequent written or oral forward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. We do not undertake any obligation to release publicly any revisions to these forward-looking statements to reflect events or circumstances after the date of this prospectus or to reflect the occurrence of unanticipated events, except as may be required under applicable U.S. securities law. If we do update one or more forward-looking statements, no inference should be drawn that we will make additional updates with respect to those or other forward-looking statements.

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the securities offered hereby. This prospectus, which constitutes a part of the registration statement, does not contain all of the information set forth in the registration statement, the exhibits filed therewith or the documents incorporated by reference therein. For further information about us and the securities offered hereby, reference is made to the registration statement, the exhibits filed therewith and the documents incorporated by reference therein. Statements contained in this prospectus regarding the contents of any contract or any other document that is filed as an exhibit to the registration statement are not necessarily complete, and in each instance, we refer you to the copy of such contract or other document filed as an exhibit to the registration statement.

We are subject to the informational requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act and are required to file annual, quarterly and other reports, proxy statements and other information with the SEC. The SEC maintains an Internet site (http://www.sec.gov) that contains reports, proxy and information statements, and various other information about us. You may also inspect the documents described herein at our principal executive offices, 1600 Fairview Avenue East, Suite 100 Seattle, WA 98102, during normal business hours.

Information about us is also available at our website at www.chinooktx.com. However, the information on our website is not a part of this prospectus and is not incorporated by reference into this prospectus.

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INCORPORATION OF INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with the SEC, which means that we can disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information we file later with the SEC will automatically update and supersede this information. A Current Report (or portion thereof) furnished, but not filed, on Form 8-K shall not be incorporated by reference into this prospectus. We incorporate by reference the documents listed below and any future filings we make with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Exchange Act prior to the termination of any offering of securities made by this prospectus:

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, filed with the SEC on April 7, 2021; and

• the description of our common stock contained in our registration statement on Form 8-A filed with the SEC on April 10, 2015 under Section 12 of the Exchange Act, including any amendment or report filed for the purpose of updating such description.

All reports; and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, including all such documents we may file with the SEC after the date of the initial registration statement and prior to the effectiveness of the registration statement, but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference in this prospectus and deemed to be part of this prospectus from the date of the filing of such reports and documents.

We will furnish without charge to you, on written or oral request, a copy of any or all of such documents that has been incorporated herein by reference (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into the documents that this prospectus incorporates). Written or oral requests for copies should be directed to Chinook Therapeutics, Inc., Attn: Investor Relations, 1600 Fairview Avenue East, Suite 100 Seattle, WA 98102, and our telephone number is (206) 485-7051. See the section of this prospectus entitled “Where You Can Find More Information” for information concerning how to obtain copies of materials that we file with the SEC.

Any statement contained in this prospectus, or in a document, all or a portion of which is incorporated by reference, shall be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, any prospectus supplement or any document incorporated by reference modifies or supersedes such statement. Any such statement so modified or superseded shall not, except as so modified or superseded, constitute a part of this prospectus.

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PLAN OF DISTRIBUTION

We may sell the securities covered by this prospectus to one or more underwriters for public offering and sale by them, and may also sell the securities to investors directly or through agents. We will name any underwriter or agent involved in the offer and sale of securities in the applicable prospectus supplement. We have reserved the right to sell or exchange securities directly to investors on our own behalf in jurisdictions where we are authorized to do so. We may distribute the securities from time to time in one or more transactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time. We will name in a prospectus supplement any agent involved in the offer or sale of our securities. Unless otherwise indicated in a prospectus supplement, an agent will be acting on a best efforts basis, and a dealer will purchase securities as a principal for resale at varying prices to be determined by the dealer.

If we utilize an underwriter in the sale of the securities being offered by this prospectus, we will execute an underwriting agreement with the underwriter at the time of sale and we will provide the name of any underwriter in the prospectus supplement that the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agent.

We will provide in the applicable prospectus supplement any compensation we pay to underwriters, dealers, or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act of 1933, as amended, or the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. In compliance with the guidelines of the Financial Industry Regulatory Authority, Inc. (“FINRA”), the aggregate maximum discount, commission or agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer shall be fair and reasonable. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, and to reimburse them for certain expenses. We may grant underwriters who participate in the distribution of our securities under this prospectus an option to purchase additional securities in connection with the distribution.

The securities we offer under this prospectus may or may not be listed through The Nasdaq Global Select Market or any other securities exchange. To facilitate the offering of securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such short positions by making purchases in the open market or by exercising their option to purchase additional securities. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a

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level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and they may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in these sale transactions will be an underwriter and will be identified in the applicable prospectus supplement. In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus. The financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

We will file a prospectus supplement to describe the terms of any offering of our securities covered by this prospectus. The prospectus supplement will disclose:

• the terms of the offer;

• the names of any underwriters, including any managing underwriters, as well as any dealers or agents;

• the purchase price of the securities from us;

• the net proceeds to us from the sale of the securities;

• any delayed delivery arrangements;

• any options under which underwriters, if any, may purchase additional securities from us;

• any underwriting discounts, commissions or other items constituting underwriters’ compensation, and any commissions paid to agents;

• in a subscription rights offering, whether we have engaged dealer-managers to facilitate the offering or subscription, including their name or names and compensation;

• any public offering price; and

• other facts material to the transaction.

We will bear all or substantially all of the costs, expenses and fees in connection with the registration of our securities under this prospectus. The underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise or the securities are sold by us to an underwriter in a firm commitment underwritten offering. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the second business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than two scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

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DESCRIPTION OF CAPITAL STOCK

General

The following is a summary description of the material terms of our capital stock. The description of capital stock is intended as a summary and is qualified in its entirety by reference to our restated certificate of incorporation, as amended (“certificate of incorporation”), and our amended and restated bylaws, as amended (“bylaws”), copies of which are filed as exhibits to our most recent Annual Report on Form 10-K and are incorporated by reference herein. We encourage you to read our certificate of incorporation, our bylaws and the applicable provisions of the Delaware General Corporation Law, or DGCL, for additional information.

Our certificate of incorporation authorizes us to issue up to 300,000,000 shares of common stock, $0.0001 par value per share, and 10,000,000 shares of preferred stock, $0.0001 par value per share.

As of December 31, 2020, there were 42,282,381 shares of our common stock outstanding, and no shares of preferred stock outstanding.

Common Stock

Voting Rights

Each holder of our common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Under our certificate of incorporation and bylaws, our stockholders do not have cumulative voting rights. Because of this, the holders of a majority of the shares of common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they should so choose.

Dividends

Subject to preferences that may be applicable to any then-outstanding preferred stock, holders of common stock are entitled to receive ratably those dividends, if any, as may be declared from time to time by the board of directors out of legally available funds.

Liquidation

In the event of our liquidation, dissolution or winding up, holders of common stock will be entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then-outstanding shares of preferred stock.

Rights and Preferences

Holders of common stock have no preemptive, conversion or subscription rights and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Anti-Takeover Provisions

Certificate of Incorporation and Bylaws

Our certificate of incorporation and bylaws provide that all stockholder actions must be effected at a duly called meeting of stockholders and not by written consent. A special meeting of stockholders may be called by the chairman of our board of directors, the majority of our whole board of directors, or our chief executive officer.

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Our certificate of incorporation provides for our board of directors to be divided into three classes, with staggered three-year terms. As a result, only one class of directors is elected at each annual meeting of stockholders, with the other classes continuing for the remainder of their respective three-year terms. Stockholders have no cumulative voting rights, and the stockholders representing a majority of the shares of common stock entitled to vote in any election of directors may elect all of the directors standing for election. In addition, our certificate of incorporation provides that stockholders may remove directors only for cause and only by the affirmative vote of the holders of at least sixty-six and two-thirds percent (66-2/3%) in voting power of our stock entitled to vote thereon.

Our certificate of incorporation further provides that the affirmative vote of holders of at least sixty-six and two-thirds percent (66-2/3%) of the voting power of all of the then outstanding shares of voting stock, voting as a single class, will be required to amend certain provisions of our certificate of incorporation, including provisions relating to the size of the board, removal of directors, special meetings, actions by written consent and cumulative voting. The affirmative vote of holders of at least sixty-six and two-thirds percent (66-2/3%) of the voting power of all of the then outstanding shares of voting stock, voting as a single class, is required to amend or repeal our bylaws, although our bylaws may be amended by a simple majority vote of our board of directors.

The foregoing provisions make it more difficult for our existing stockholders to replace our board of directors as well as for another party to obtain control of us by replacing our board of directors. Since our board of directors has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management. In addition, the authorization of undesignated preferred stock makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to cause a change in control of us.

These provisions are intended to enhance the likelihood of continued stability in the composition of our board of directors and its policies and to discourage certain types of transactions that may involve an actual or threatened acquisition of us. These provisions are also designed to reduce our vulnerability to an unsolicited acquisition proposal and to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging a change of control of our company or changes in our board of directors that our stockholders might consider favorable. As a consequence, these provisions also may inhibit fluctuations in the market price of our stock that could result from actual or rumored takeover attempts.

Section 203 of the Delaware General Corporation Law

We are subject to Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in a business combination with any interested stockholder for a period of three years following the date the person became an interested stockholder, with the following exceptions:

• before such date, the board of directors of the corporation approved either the business combination or the transaction that resulted in the stockholder becoming an interested holder;

• upon completion of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction began, excluding for purposes of determining the voting stock outstanding (but not the outstanding voting stock owned by the interested stockholder) those shares owned (a) by persons who are directors and also officers and (b) pursuant to employee stock plans in which employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; and

• on or after such date, the business combination is approved by the board of directors and authorized at an annual or special meeting of the stockholders, and not by written consent, by the affirmative vote of at least 66 2/3% of the outstanding voting stock that is not owned by the interested stockholder.

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In general, Section 203 of the DGCL defines business combination to include the following:

• any merger or consolidation involving the corporation and the interested stockholder;

• any sale, transfer, pledge or other disposition of 10% or more of the assets of the corporation involving the interested stockholder;

• subject to certain exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder;

• subject to certain exceptions, any transaction involving the corporation that has the effect of increasing the proportionate share of the stock or any class or series of the corporation beneficially owned by the interested stockholder; and

• the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits by or through the corporation.

Section 203 of the DGCL defines an “interested stockholder” as an entity or person who, together with the entity’s or person’s affiliates and associates, beneficially owns, or is an affiliate of the corporation and within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation. A Delaware corporation may “opt out” of these provisions with an express provision in its certificate of incorporation. We have not opted out of these provisions, which may as a result, discourage or prevent mergers or other takeover or change of control attempts of us.

Choice of Forum

Our certificate of incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for any derivative action or proceeding brought on our behalf; any action asserting a breach of fiduciary duty; any action asserting a claim against us arising pursuant to the DGCL, our certificate of incorporation or our bylaws; or any action asserting a claim against us that is governed by the internal affairs doctrine. The enforceability of similar choice of forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings and it is possible that a court could find these types of provisions to be inapplicable or unenforceable. Similarly, our bylaws provide that (a) the Court of Chancery of the State of Delaware will be the sole and exclusive forum for any derivative action or proceeding brought on our behalf; any action asserting a breach of fiduciary duty; any action asserting a claim against us arising pursuant to the DGCL; or any action asserting a claim against us that is governed by the internal affairs doctrine, and (b) the federal district courts of the United Stated of America are the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act of 1933, as amended. Although our bylaws contain the choice of forum provision described above, it is possible that a court could find that such provisions are inapplicable for a particular claim or action or that such provisions are unenforceable.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent and registrar’s address is 250 Royall Street, Canton, Massachusetts 02021.

Exchange Listing

Our common stock is listed on the Nasdaq Global Select Market under the symbol “KDNY.”

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DESCRIPTION OF DEBT SECURITIES

General

We will issue the debt securities offered by this prospectus and any accompanying prospectus supplement under an indenture to be entered into between us and the trustee identified in the applicable prospectus supplement. The terms of the debt securities will include those stated in the indenture and those made part of the indenture by reference to the Trust Indenture Act of 1939, as in effect on the date of the indenture. We have filed a copy of the form of indenture as an exhibit to the registration statement in which this prospectus is included. The indenture will be subject to and governed by the terms of the Trust Indenture Act of 1939. Unless otherwise specified in the applicable prospectus supplement, the debt securities will represent our direct, unsecured obligations and will rank equally with all of our other unsecured indebtedness.

We may offer under this prospectus up to an aggregate principal amount of $275,000,000 in debt securities, or if debt securities are issued at a discount, or in a foreign currency, foreign currency units or composite currency, the principal amount as may be sold for an aggregate public offering price of up to $275,000,000. We may issue the debt securities in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will describe the particular terms of each series of debt securities in a prospectus supplement relating to that series, which we will file with the SEC. The prospectus supplement relating to the particular series of debt securities being offered will specify the particular amounts, prices and terms of those debt securities. These terms may include:

• the title of the series;

• the aggregate principal amount, and, if a series, the total amount authorized and the total amount outstanding;

• the issue price or prices, expressed as a percentage of the aggregate principal amount of the debt securities;

• any limit on the aggregate principal amount;

• the date or dates on which principal is payable;

• the interest rate or rates (which may be fixed or variable) or, if applicable, the method used to determine such rate or rates;

• the date or dates from which interest, if any, will be payable and any regular record date for the interest payable;

• the place or places where principal and, if applicable, premium and interest, is payable;

• the terms and conditions upon which we may, or the holders may require us to, redeem or repurchase the debt securities;

• the denominations in which such debt securities may be issuable, if other than denominations of $1,000 or any integral multiple of that number;

• whether the debt securities are to be issuable in the form of certificated securities (as described below) or global securities (as described below);

• the portion of principal amount that will be payable upon declaration of acceleration of the maturity date if other than the principal amount of the debt securities;

• the currency of denomination;

• the designation of the currency, currencies or currency units in which payment of principal and, if applicable, premium and interest, will be made;

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• if payments of principal and, if applicable, premium or interest, on the debt securities are to be made in one or more currencies or currency units other than the currency of denomination, the manner in which the exchange rate with respect to such payments will be determined;

• if amounts of principal and, if applicable, premium and interest may be determined by reference to an index based on a currency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index, then the manner in which such amounts will be determined;

• the provisions, if any, relating to any collateral provided for such debt securities;

• any addition to or change in the covenants and/or the acceleration provisions described in this prospectus or in the indenture;

• any events of default, if not otherwise described below under “Events of Default”;

• the terms and conditions, if any, for conversion into or exchange for shares of our common stock or preferred stock;

• any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents; and

• the terms and conditions, if any, upon which the debt securities shall be subordinated in right of payment to our other indebtedness.

We may issue discount debt securities that provide for an amount less than the stated principal amount to be due and payable upon acceleration of the maturity of such debt securities in accordance with the terms of the indenture. We may also issue debt securities in bearer form, with or without coupons. If we issue discount debt securities or debt securities in bearer form, we will describe material U.S. federal income tax considerations and other material special considerations which apply to these debt securities in the applicable prospectus supplement.

We may issue debt securities denominated in or payable in a foreign currency or currencies or a foreign currency unit or units. If we do, we will describe the restrictions, elections, and general tax considerations relating to the debt securities and the foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Debt securities offered under this prospectus and any prospectus supplement will be subordinated in right of payment to certain of our outstanding senior indebtedness. In addition, we will seek the consent of the holders of any such senior indebtedness prior to issuing any debt securities under this prospectus to the extent required by the agreements evidencing such senior indebtedness.

Registrar and Paying Agent

The debt securities may be presented for registration of transfer or for exchange at the corporate trust office of the security registrar or at any other office or agency that we maintain for those purposes. In addition, the debt securities may be presented for payment of principal, interest and any premium at the office of the paying agent or at any office or agency that we maintain for those purposes.

Conversion or Exchange Rights

Debt securities may be convertible into or exchangeable for shares of our common stock. The terms and conditions of conversion or exchange will be stated in the applicable prospectus supplement. The terms will include, among others, the following:

• the conversion or exchange price;

• the conversion or exchange period;

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• provisions regarding the convertibility or exchangeability of the debt securities, including who may convert or exchange;

• events requiring adjustment to the conversion or exchange price;

• provisions affecting conversion or exchange in the event of our redemption of the debt securities; and

• any anti-dilution provisions, if applicable.

Registered Global Securities

If we decide to issue debt securities in the form of one or more global securities, then we will register the global securities in the name of the depositary for the global securities or the nominee of the depositary, and the global securities will be delivered by the trustee to the depositary for credit to the accounts of the holders of beneficial interests in the debt securities.

The prospectus supplement will describe the specific terms of the depositary arrangement for debt securities of a series that are issued in global form. None of us, the trustee, any payment agent or the security registrar will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to these beneficial ownership interests.

No Protection in the Event of Change of Control

The indenture does not have any covenants or other provisions providing for a put or increased interest or otherwise that would afford holders of our debt securities additional protection in the event of a recapitalization transaction, a change of control or a highly leveraged transaction. If we offer any covenants or provisions of this type with respect to any debt securities covered by this prospectus, we will describe them in the applicable prospectus supplement.

Covenants

Unless otherwise indicated in this prospectus or the applicable prospectus supplement, our debt securities will not have the benefit of any covenants that limit or restrict our business or operations, the pledging of our assets or the incurrence by us of indebtedness. We will describe in the applicable prospectus supplement any material covenants in respect of a series of debt securities.

Merger, Consolidation or Sale of Assets

The form of indenture provides that we will not consolidate with or merge into any other person or convey, transfer, sell or lease our properties and assets substantially as an entirety to any person, unless:

• we are the surviving person of such merger or consolidation, or if we are not the surviving person, the person formed by the consolidation or into or with which we are merged or the person to which our properties and assets are conveyed, transferred, sold or leased, is a corporation organized and existing under the laws of the U.S., any state or the District of Columbia or a corporation or comparable legal entity organized under the laws of a foreign jurisdiction and has expressly assumed all of our obligations, including the payment of the principal of and, premium, if any, and interest on the debt securities and the performance of the other covenants under the indenture; and

• immediately before and immediately after giving effect to the transaction on a pro forma basis, no event of default, and no event which, after notice or lapse of time or both, would become an event of default, has occurred and is continuing under the indenture.

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Events of Default

Unless otherwise specified in the applicable prospectus supplement, the following events will be events of default under the indenture with respect to debt securities of any series:

• we fail to pay any principal or premium, if any, when it becomes due;

• we fail to pay any interest within 30 days after it becomes due;

• we fail to observe or perform any other covenant in the debt securities or the indenture for 90 days after written notice specifying the failure from the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series; and

• certain events involving bankruptcy, insolvency or reorganization of us or any of our significant subsidiaries.

The trustee may withhold notice to the holders of the debt securities of any series of any default, except in payment of principal of or premium, if any, or interest on the debt securities of a series, if the trustee considers it to be in the best interest of the holders of the debt securities of that series to do so.

If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization) occurs, and is continuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of any series may accelerate the maturity of the debt securities. If this happens, the entire principal amount, plus the premium, if any, of all the outstanding debt securities of the affected series plus accrued interest to the date of acceleration will be immediately due and payable. At any time after the acceleration, but before a judgment or decree based on such acceleration is obtained by the trustee, the holders of a majority in aggregate principal amount of outstanding debt securities of such series may rescind and annul such acceleration if:

• all events of default (other than nonpayment of accelerated principal, premium or interest) have been cured or waived;

• all lawful interest on overdue interest and overdue principal has been paid; and

• the rescission would not conflict with any judgment or decree.

In addition, if the acceleration occurs at any time when we have outstanding indebtedness that is senior to the debt securities, the payment of the principal amount of outstanding debt securities may be subordinated in right of payment to the prior payment of any amounts due under the senior indebtedness, in which case the holders of debt securities will be entitled to payment under the terms prescribed in the instruments evidencing the senior indebtedness and the indenture.

If an event of default resulting from certain events of bankruptcy, insolvency or reorganization occurs, the principal, premium and interest amount with respect to all of the debt securities of any series will be due and payable immediately without any declaration or other act on the part of the trustee or the holders of the debt securities of that series.

The holders of a majority in principal amount of the outstanding debt securities of a series will have the right to waive any existing default or compliance with any provision of the indenture or the debt securities of that series and to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, subject to certain limitations specified in the indenture.

No holder of any debt security of a series will have any right to institute any proceeding with respect to the indenture or for any remedy under the indenture, unless:

• the holder gives to the trustee written notice of a continuing event of default;

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• the holders of at least 25% in aggregate principal amount of the outstanding debt securities of the affected series make a written request and offer reasonable indemnity to the trustee to institute a proceeding as trustee;

• the trustee fails to institute a proceeding within 60 days after such request; and

• the holders of a majority in aggregate principal amount of the outstanding debt securities of the affected series do not give the trustee a direction inconsistent with such request during such 60-day period.

These limitations do not, however, apply to a suit instituted for payment on debt securities of any series on or after the due dates expressed in the debt securities.

We will periodically deliver certificates to the trustee regarding our compliance with our obligations under the indenture.

Modification and Waiver

From time to time, we and the trustee may, without the consent of holders of the debt securities of one or more series, amend the indenture or the debt securities of one or more series, or supplement the indenture, for certain specified purposes, including:

• to provide that the surviving entity following a change of control permitted under the indenture will assume all of our obligations under the indenture and debt securities;

• to provide for certificated debt securities in addition to uncertificated debt securities;

• to comply with any requirements of the SEC under the Trust Indenture Act of 1939;

• to provide for the issuance of and establish the form and terms and conditions of debt securities of any series as permitted by the indenture;

• to cure any ambiguity, defect or inconsistency, or make any other change that does not materially and adversely affect the rights of any holder; and

• to appoint a successor trustee under the indenture with respect to one or more series.

From time to time we and the trustee may, with the consent of holders of at least a majority in principal amount of an outstanding series of debt securities, amend or supplement the indenture or the debt securities series, or waive compliance in a particular instance by us with any provision of the indenture or the debt securities. We may not, however, without the consent of each holder affected by such action, modify or supplement the indenture or the debt securities or waive compliance with any provision of the indenture or the debt securities in order to:

• reduce the amount of debt securities whose holders must consent to an amendment, supplement, or waiver to the indenture or such debt security;

• reduce the rate of or change the time for payment of interest or reduce the amount of or postpone the date for payment of sinking fund or analogous obligations;

• reduce the principal of or change the stated maturity of the debt securities;

• make any debt security payable in money other than that stated in the debt security;

• change the amount or time of any payment required or reduce the premium payable upon any redemption, or change the time before which no such redemption may be made;

• waive a default in the payment of the principal of, premium, if any, or interest on the debt securities or a redemption payment;

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• waive a redemption payment with respect to any debt securities or change any provision with respect to redemption of debt securities; or

• take any other action otherwise prohibited by the indenture to be taken without the consent of each holder affected by the action.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

The indenture permits us, at any time, to elect to discharge our obligations with respect to one or more series of debt securities by following certain procedures described in the indenture. These procedures will allow us either:

• to defease and be discharged from any and all of our obligations with respect to any debt securities except for the following obligations (which discharge is referred to as “legal defeasance”):

1. to register the transfer or exchange of such debt securities;

2. to replace temporary or mutilated, destroyed, lost or stolen debt securities;

3. to compensate and indemnify the trustee; or

4. to maintain an office or agency in respect of the debt securities and to hold monies for payment in trust; or

• to be released from our obligations with respect to the debt securities under certain covenants contained in the indenture, as well as any additional covenants which may be contained in the applicable supplemental indenture (which release is referred to as “covenant defeasance”).

In order to exercise either defeasance option, we must irrevocably deposit with the trustee or other qualifying trustee, in trust for that purpose:

• money;

• U.S. Government Obligations (as described below) or Foreign Government Obligations (as described below) that through the scheduled payment of principal and interest in accordance with their terms will provide money; or

• a combination of money and/or U.S. Government Obligations and/or Foreign Government Obligations sufficient in the written opinion of a nationally-recognized firm of independent accountants to provide money;

that, in each case specified above, provides a sufficient amount to pay the principal of, premium, if any, and interest, if any, on the debt securities of the series, on the scheduled due dates or on a selected date of redemption in accordance with the terms of the indenture.

In addition, defeasance may be effected only if, among other things:

• in the case of either legal or covenant defeasance, we deliver to the trustee an opinion of counsel, as specified in the indenture, stating that as a result of the defeasance neither the trust nor the trustee will be required to register as an investment company under the Investment Company Act of 1940;

• in the case of legal defeasance, we deliver to the trustee an opinion of counsel stating that we have received from, or there has been published by, the Internal Revenue Service a ruling to the effect that, or there has been a change in any applicable federal income tax law with the effect that (and the opinion shall confirm that), the holders of outstanding debt securities will not recognize income, gain or loss for U.S. federal income tax purposes solely as a result of such legal defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner, including as a result of prepayment, and at the same times as would have been the case if legal defeasance had not occurred;

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• in the case of covenant defeasance, we deliver to the trustee an opinion of counsel to the effect that the holders of the outstanding debt securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of covenant defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if covenant defeasance had not occurred; and

• certain other conditions described in the indenture are satisfied.

If we fail to comply with our remaining obligations under the indenture and applicable supplemental indenture after a covenant defeasance of the indenture and applicable supplemental indenture, and the debt securities are declared due and payable because of the occurrence of any undefeased event of default, the amount of money and/or U.S. Government Obligations and/or Foreign Government Obligations on deposit with the trustee could be insufficient to pay amounts due under the debt securities of the affected series at the time of acceleration. We will, however, remain liable in respect of these payments.

The term “U.S. Government Obligations” as used in the above discussion means securities that are direct obligations of or non-callable obligations guaranteed by the United States of America for the payment of which obligation or guarantee the full faith and credit of the United States of America is pledged.

The term “Foreign Government Obligations” as used in the above discussion means, with respect to debt securities of any series that are denominated in a currency other than U.S. dollars, (1) direct obligations of the government that issued or caused to be issued such currency for the payment of which obligations its full faith and credit is pledged or (2) obligations of a person controlled or supervised by or acting as an agent or instrumentality of such government the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by that government, which in either case under clauses (1) or (2), are not callable or redeemable at the option of the issuer.

Regarding the Trustee

We will identify the trustee with respect to any series of debt securities in the prospectus supplement relating to the applicable debt securities. You should note that if the trustee becomes a creditor of ours, the indenture and the Trust Indenture Act of 1939 limit the rights of the trustee to obtain payment of claims in certain cases, or to realize on certain property received in respect of any such claim, as security or otherwise. The trustee and its affiliates may engage in, and will be permitted to continue to engage in, other transactions with us and our affiliates. If, however, the trustee acquires any “conflicting interest” within the meaning of the Trust Indenture Act of 1939, it must eliminate such conflict or resign.

The holders of a majority in principal amount of the then outstanding debt securities of any series may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee. If an event of default occurs and is continuing, the trustee, in the exercise of its rights and powers, must use the degree of care and skill of a prudent person in the conduct of his or her own affairs. Subject to that provision, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any of the holders of the debt securities, unless they have offered to the trustee reasonable indemnity or security.

No Individual Liability of Incorporators, Stockholders, Officers or Directors

Each indenture provides that no incorporator and no past, present or future stockholder, officer or director of our company or any successor corporation in those capacities will have any individual liability for any of our obligations, covenants or agreements under the debt securities or such indenture.

Governing Law

The indentures and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York.

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DESCRIPTION OF WARRANTS

General

We may issue warrants for the purchase of our debt securities, preferred stock, common stock, or any combination thereof. Warrants may be issued independently or together with our debt securities, preferred stock or common stock and may be attached to or separate from any offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent. The warrant agent will act solely as our agent in connection with the warrants. The warrant agent will not have any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. This summary of certain provisions of the warrants is not complete. For the terms of a particular series of warrants, you should refer to the prospectus supplement for that series of warrants and the warrant agreement for that particular series.

Debt Warrants

The prospectus supplement relating to a particular issue of warrants to purchase debt securities will describe the terms of the debt warrants, including the following:

• the title of the debt warrants;

• the offering price for the debt warrants, if any;

• the aggregate number of the debt warrants;

• the designation and terms of the debt securities, including any conversion rights, purchasable upon exercise of the debt warrants;

• if applicable, the date from and after which the debt warrants and any debt securities issued with them will be separately transferable;

• the principal amount of debt securities that may be purchased upon exercise of a debt warrant and the exercise price for the warrants, which may be payable in cash, securities or other property;

• the dates on which the right to exercise the debt warrants will commence and expire;

• if applicable, the minimum or maximum amount of the debt warrants that may be exercised at any one time;

• whether the debt warrants represented by the debt warrant certificates or debt securities that may be issued upon exercise of the debt warrants will be issued in registered or bearer form;

• information with respect to book-entry procedures, if any;

• the currency or currency units in which the offering price, if any, and the exercise price are payable;

• if applicable, a discussion of material U.S. federal income tax considerations;

• the antidilution provisions of the debt warrants, if any;

• the redemption or call provisions, if any, applicable to the debt warrants;

• any provisions with respect to the holder’s right to require us to repurchase the debt warrants upon a change in control or similar event; and

• any additional terms of the debt warrants, including procedures and limitations relating to the exchange, exercise, and settlement of the debt warrants.

Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations. Debt warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in

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the prospectus supplement. Prior to the exercise of their debt warrants, holders of debt warrants will not have any of the rights of holders of the debt securities purchasable upon exercise and will not be entitled to payment of principal or any premium, if any, or interest on the debt securities purchasable upon exercise.

Equity Warrants

The prospectus supplement relating to a particular series of warrants to purchase our common stock or preferred stock will describe the terms of the warrants, including the following:

• the title of the warrants;

• the offering price for the warrants, if any;

• the aggregate number of warrants;

• the designation and terms of the common stock or preferred stock that may be purchased upon exercise of the warrants;

• if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each security;

• if applicable, the date from and after which the warrants and any securities issued with the warrants will be separately transferable;

• the number of shares of common stock or preferred stock that may be purchased upon exercise of a warrant and the exercise price for the warrants;

• the dates on which the right to exercise the warrants shall commence and expire;

• if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;

• the currency or currency units in which the offering price, if any, and the exercise price are payable;

• if applicable, a discussion of material U.S. federal income tax considerations;

• the antidilution provisions of the warrants, if any;

• the redemption or call provisions, if any, applicable to the warrants;

• any provisions with respect to a holder’s right to require us to repurchase the warrants upon a change in control or similar event; and

• any additional terms of the warrants, including procedures and limitations relating to the exchange, exercise and settlement of the warrants.

Holders of equity warrants will not be entitled:

• to vote, consent, or receive dividends;

• receive notice as stockholders with respect to any meeting of stockholders for the election of our directors or any other matter; or

• exercise any rights as stockholders.

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DESCRIPTION OF SUBSCRIPTION RIGHTS

We may issue subscription rights to purchase our common stock, preferred stock or debt securities. These subscription rights may be offered independently or together with any other security offered hereby and may or may not be transferable by the stockholder receiving the subscription rights in such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

The prospectus supplement relating to any subscription rights we offer, if any, will, to the extent applicable, include specific terms relating to the offering, including some or all of the following:

• the price, if any, for the subscription rights;

• the exercise price payable for our common stock, preferred stock or debt securities upon the exercise of the subscription rights;

• the number of subscription rights to be issued to each stockholder;

• the number and terms of our common stock, preferred stock or debt securities which may be purchased per each subscription right;

• the extent to which the subscription rights are transferable;

• any other terms of the subscription rights, including the terms, procedures and limitations relating to the exchange and exercise of the subscription rights;

• the date on which the right to exercise the subscription rights shall commence, and the date on which the subscription rights shall expire;

• the extent to which the subscription rights may include an over-subscription privilege with respect to unsubscribed securities or an over-allotment privilege to the extent the securities are fully subscribed; and

• if applicable, the material terms of any standby underwriting or purchase arrangement which may be entered into by us in connection with the offering of subscription rights.

The description in the applicable prospectus supplement of any subscription rights we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable subscription rights certificate, which will be filed with the SEC if we offer subscription rights. We urge you to read the applicable subscription rights certificate and any applicable prospectus supplement in their entirety.

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DESCRIPTION OF UNITS

We may issue units consisting of some or all of the securities described above, in any combination, including common stock, preferred stock, warrants and/or debt securities. The terms of these units will be set forth in a prospectus supplement. The description of the terms of these units in the related prospectus supplement will not be complete. You should refer to the applicable form of unit and unit agreement for complete information with respect to these units.

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LEGAL MATTERS

Fenwick & West LLP, Seattle, Washington, will issue an opinion about certain legal matters with respect to the securities. Any underwriters or agents will be advised about legal matters relating to any offering by their own counsel.

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EXPERTS

The financial statements incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2020 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

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6,000,000 Shares

CHINOOK THERAPEUTICS, INC.

PROSPECTUS SUPPLEMENT

JOINT BOOK-RUNNING MANAGERS

SVB Leerink

Evercore ISI

LEAD MANAGERS

Oppenheimer & Co. Wedbush PacGrow H.C. Wainwright & Co.

November    , 2021