treatment of several disease states and indications, including HLHS and Alzheimer’s Disease, obtaining regulatory approvals, capital expenditures, working capital and other general corporate purposes. Our stockholders may not agree with the manner in which our management chooses to allocate and spend the net proceeds. Moreover, our management may use the net proceeds for corporate purposes that may not increase the market price of our Class A common stock or other securities. See the section of this prospectus titled “Where You Can Find More InformationUse of Proceeds.”

Raising additional capital may cause future dilution to our stockholders, restrict our operations or require us to relinquish rights to our technologies or current product candidates.

Until such time, if ever, as we can generate the cash we need from operations, we expect to finance our cash needs through a combination of private and public equity offerings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. We do not currently have any committed external source of funds and in order to raise additional capital, we may offer and issue additional shares of our common stock or other securities convertible into or exchangeable for our common stock in the future. We are generally not restricted from issuing additional securities, including shares of common stock, securities that are convertible into or exchangeable for, or that represent the right to receive, common stock or substantially similar securities. The issuance of securities in future offerings may cause further dilution to our stockholders, including investors in this offering. We cannot assure you that we will be able to sell 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 other securities in the future could have rights superior to existing stockholders. To the extent that we raise additional capital through the sale of Class A common stock or securities convertible into or exchangeable for Class A common stock, the ownership interest of our shareholders will be diluted, and the terms of these new securities may include liquidation or other preferences that materially adversely affect the rights of our shareholders. Debt financing, if available, would increase our fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends.

DIVIDEND POLICYIf we raise funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third-parties, we may have to relinquish valuable rights to our intellectual property, future revenue streams, research programs or current or future product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds when needed, we may be required to delay, scale back or discontinue the development and commercialization of one or more of our product candidates, delay our pursuit of potential licenses or acquisitions, or grant rights to develop and market current or future therapeutic candidates that we would otherwise prefer to develop and market ourselves.

In addition, we have a significant number of stock options, restricted stock units and warrants outstanding. To the extent that outstanding stock options or warrants have been or may be exercised or other shares issued, you may experience further dilution.

A substantial number of shares of our Class A common stock are being sold in this offering, which could cause the price of our Class A common stock to decline.

In this offering we are selling up to shares of Class A common stock. In addition, we are also selling Class A common warrants to purchase up to     shares of Class A common stock. In the aggregate, the maximum shares that could be issued in this offering represent approximately    % of our outstanding Class A common stock and Class B common stock as of   , 2024, after giving effect to this offering. This sale and any future sales of a substantial number of shares of our Class A common stock in the public market, or the perception that such sales may occur, could adversely affect the price of our Class A common stock on the Nasdaq Capital Market. We cannot predict the effect, if any, that market sales of those shares of Class A common stock or the availability of those shares of Class A common stock for sale will have on the market price of our Class A common stock.

We do not currently intend to pay dividends on our Class A common stock and, consequently, your ability to achieve a return on your investment will depend on appreciation of the value of our Class A common stock.

We have never declared noror paid any cash dividends andon our equity securities. We currently intend toanticipate that we will retain all our cash and anyfuture earnings for use inthe development, operation and expansion of our business and therefore, do not anticipate declaring or paying any cash dividends infor the foreseeable future. Any return to stockholders will therefore be limited to any appreciation in the value of our Class A common stock, which is not certain.

The price of our Class A common stock may be volatile or may decline regardless of our operating performance, and shareholders may not be able to resell their shares at or above the price at which they purchase those shares.

Trading volume in shares of our Class A common stock on the Nasdaq Capital Market has been limited. You may not be able to sell your shares quickly or at the market price if trading in shares of our Class A common stock is not active. An active or liquid market in our Class A common stock may not develop or, if it does develop, it may not sustain. As a result of these and other factors, shareholders may not be able to resell their shares of our Class A common stock at or above the price at which they purchase those shares in this offering.

Further, an inactive market may also impair our ability to raise capital by selling shares of our Class A common stock and may impair our ability to enter into strategic collaborations or acquire companies or products by using our shares of Class A common stock as consideration.

If you purchase our securities in this offering, you may incur immediate and substantial dilution in the book value of your shares of Class A common stock.

You may suffer immediate and substantial dilution in the net tangible book value of the Class A common stock you purchase in this offering. Based on the assumed public offering price of $ per share and accompanying Class A common warrant, the last reported price of our Class A common stock on the Nasdaq Capital Market on     , 2024, we estimate our as adjusted net tangible book value per share after this offering will be $    . As a result, purchasers of securities in this offering will experience an immediate increase of $   per share in net tangible book value of the Class A common stock. See the section of this prospectus titled “Dilution” for a more detailed description of these factors.

There is no public market for any pre-funded warrants or the Class A common warrants sold in this offering.

There is no established public trading market for the pre-funded warrants or Class A common warrants being sold in this offering. We will not list the pre-funded warrants or Class A common warrants on any securities exchange or nationally recognized trading system, including the Nasdaq Capital Market. Therefore, we do not expect a market to ever develop for the pre-funded warrants or Class A common warrants. Without an active market, the liquidity of the pre-funded warrants and Class A common warrants will be limited.

The pre-funded warrants and Class A common warrants are speculative in nature. Holders of the pre-funded warrants and the Class A common warrants offered hereby will have no rights as common stockholders with respect to the shares our Class A common stock underlying such warrants until such holders exercise their warrants and acquire our Class A common stock, except as otherwise provided in the pre-funded warrants and the Class A common warrants.

The pre-funded warrants and Class A common warrants do not confer any rights of Class A common stock ownership on their holders, such as voting rights or the right to receive dividends, but merely represent the right to acquire shares of Class A common stock at a fixed price. Commencing on the date of issuance, holders of pre-funded warrants and Class A common warrants may exercise their right to acquire the underlying Class A common stock and pay the respective stated warrant exercise price per share. Following this offering, the market value of the Class A common warrants is uncertain and there can be no assurance that the market value of the Class A common warrants, if any, will equal or exceed their public offering prices. There can be no assurance that the market price of the shares of Class A common stock will ever equal or exceed the exercise price of the Class A common warrants, and consequently, whether it will ever be profitable for holders of Class A common warrants to exercise the Class A common warrants.

Until holders of pre-funded warrants and Class A common warrants acquire shares of our Class A common stock upon exercise thereof, holders of such pre-funded warrants and Class A common warrants will have no rights with respect to shares of our Class A common stock, except as provided in the pre-funded warrants and Class A common warrants, respectively. Upon exercise of the pre-funded warrants and Class A common warrants, such holders will be entitled to the rights of a Class A common stockholder only as to matters for which the record date occurs after the exercise date.

Resales of our shares of Class A common stock in the public market by our stockholders as a result of this offering may cause the market price of our shares of Class A common stock to fall.

We are registeringshares of Class A common stock, as well as   shares of Class A common stock, in the aggregate, issuable upon the exercise of the pre-funded warrants and the Class A common warrants offered under this prospectus. Sales of substantial amounts of our shares of Class A common stock in the public market, or the perception that such sales might occur, could adversely affect the market price of our shares of Class A common stock. The issuance of new shares of Class A common stock could result in resales of our shares of Class A common stock by our current shareholders concerned about the potential ownership dilution of their holdings. Furthermore, in the future, we may issue additional shares of Class A common stock or other equity or debt securities exercisable or convertible into shares of common stock. Any such issuance could result in substantial dilution to our existing shareholders and could cause our stock price to decline.

Risks Related to Our Class A Common Stock and the Securities Market

The price of our Class A common stock has been, and may continue to be, volatile, which could result in substantial or total losses for investors.

The trading price of our Class A common stock has been, and may continue to be, highly volatile and subject to wide fluctuations in response to various factors, some of which we cannot control. The stock market in general, and pharmaceutical and biotechnology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies.

Broad market and industry factors may negatively affect the market price of our Class A common stock, regardless of our actual operating performance. In addition to the factors discussed in this “Risk Factors” section and elsewhere in this prospectus, these factors include:

•the timing and results, or perception of the results, of preclinical studies and clinical trials of our product candidates or those of our competitors;

•the success of competitive products or announcements by potential competitors of their product development efforts;

•regulatory actions with respect to our or our competitors’ product candidates or approved products;

•actual or anticipated changes in our growth rate relative to our competitors;

•regulatory or legal developments in the U.S. and other countries;

•developments or disputes concerning patent applications, issued patents or other proprietary rights;

•the recruitment or departure of key personnel;

•announcements by us or our competitors of significant acquisitions, strategic collaborations, joint ventures, or capital commitments;

•actual or anticipated changes in estimates as to financial results, development timelines or recommendations by securities analysts;

•fluctuations in the valuation of companies perceived by investors to be comparable to us;

•market conditions in the pharmaceutical and biotechnology sector;

•changes in the structure of healthcare payment systems;

•Class A common stock price and volume fluctuations attributable to inconsistent trading volume levels of our Class A common stock;

•announcement or expectation of additional financing efforts;

•sales of our Class A common stock by us, our insiders or our other stockholders;

•expiration of market stand-off or lock-up agreements; and

•general economic, industry and market conditions.

The realization of any of the above risks or any of a broad range of other risks, including those described in this “Risk Factors” section, could have a dramatic and adverse impact on the market price of our Class A common stock. Additionally, in the past, securities class action litigation has often been instituted against companies following periods of volatility in the market price of a company’s securities. This type of litigation, if instituted, could result in substantial costs and a diversion of management’s attention and resources.

There may not be sufficient liquidity in the market for our securities in order for investors to sell their shares.

We are a small company that is relatively unknown to stock analysts, stockbrokers, institutional investors and others in the investment community that generate or influence sales volume, and even if we came to the attention of such persons, they tend to be risk-averse and may be reluctant to follow an unproven company such as ours or purchase or recommend the purchase of our shares until such time as we became more seasoned and viable. There may be periods of several days or more when trading activity in our shares is minimal as compared to a mature issuer which has a large and steady volume of trading activity that will generally support continuous sales without an adverse effect on share price. It is possible that a broader or more active public trading market for our common stock will not develop or be sustained, or that trading levels will not continue. These factors may materially adversely affect the market price of our Class A common stock, regardless of our performance.

We will need to raise substantial additional funding. If we are unable to raise capital when needed, we could be forced to delay, scale back or discontinue some of our therapeutic candidate development programs or commercialization efforts.

The development of pharmaceutical drugs is capital intensive. We are currently advancing Lomecel-BTM into clinical development. Our current cash resources are insufficient to fund our planned operations or development plans beyond the beginning of the second quarter of 2024. We will require additional funds to advance further. If we are capital constrained, we may not be able to meet our obligations. If we are unable to meet our obligations, or we experience a disruption in our cash flows, it could limit or halt our ability to continue to develop our current product candidate or even to continue operations, either of which occurrence would have a material adverse effect on us.

We expect our expenses to continue to increase in connection with our ongoing activities, particularly as we continue the research and development of, advance the preclinical and clinical activities of, and seek marketing approval for, our current product candidate. In addition, if we obtain marketing approval for any of our current or future product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution. We may also need to raise additional funds sooner if we choose to pursue additional indications and/or geographies for our current product candidate or otherwise expand more rapidly than we presently anticipate. Furthermore, we expect to continue to incur significant costs associated with operating as a public company. If we are unable to raise capital when needed, we could be forced to delay, scale back or discontinue the development and commercialization of one or more of our therapeutic candidates, delay our pursuit of potential licenses or acquisitions, or significantly reduce our operations.

We expect that the net proceeds from recent offerings, together with our existing cash, will be sufficient to fund our operations only for various amounts of time in 2024 depending on the amount of net proceeds we obtain. Our future capital requirements will depend on and could increase significantly as a result of many factors, including:

•the scope, progress, results and costs of drug discovery, preclinical development, laboratory testing and clinical trials for our current or future therapeutic candidates;

•the potential additional expenses attributable to adjusting our development plans (including any supply-related matters) to the COVID-19 pandemic;

•the scope, prioritization and number of our research and development programs;

•the costs, timing and outcome of regulatory review of our current or future therapeutic candidates;

•our ability to establish and maintain collaborations on favorable terms, if at all;

•the achievement of milestones or occurrence of other developments that trigger payments under any additional collaboration agreements we obtain;

•the extent to which we are obligated to reimburse, or are entitled to reimbursement of, clinical trial costs under future collaboration agreements, if any;

•the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims;

•the extent to which we acquire or license other current or future therapeutic candidates and technologies;

•the costs of securing manufacturing arrangements for commercial production; and

•the costs of establishing or contracting for sales and marketing capabilities if we obtain regulatory approvals to market our current or future therapeutic candidates.

Identifying potential current or future product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve drug sales.

In addition, our current or future product candidates, if approved, may not achieve commercial success. Our commercial revenues, if any, will be derived from sales of drugs that we do not expect to be commercially available for many years, if ever. Accordingly, we will need to continue to rely on additional funding to achieve our business objectives.

Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize our current or future therapeutic candidates.

Disruptions in the financial markets in general have made equity and debt financing more difficult to obtain and may have a material adverse effect on our ability to meet our fundraising needs. We cannot guarantee that future financing will be available in sufficient amounts or on terms favorable to us, if at all. Moreover, the terms of any financing may adversely affect the holdings or the rights of our stockholders and the issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our Class A common stock to decline. The sale of additional equity or convertible securities would dilute all of our stockholders. The incurrence of indebtedness could result in fixed payment obligations, and we may be required to agree to certain restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. We could also be required to seek funds through arrangements with collaborators or otherwise at an earlier stage than otherwise would be desirable and we may be required to relinquish rights to some of our technologies or current or future therapeutic candidates or otherwise agree to terms unfavorable to us, any of which may have a material adverse effect on our business, operating results and prospects.

If we are unable to obtain funding on a timely basis, we may be required to significantly delay, scale back or discontinue one or more of our research or development programs or the commercialization of any therapeutic candidates or be unable to expand our operations or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition and results of operations.

We have received notice from Nasdaq that the price of our Class A common stock does not satisfy the price minimum required for the continued listing of our Class A common stock on the Nasdaq Capital Market. While we have an opportunity to cure this non-compliance, the loss of the listing of our Class A common stock on the Nasdaq Capital Market would in all likelihood result in significantly less liquidity for our Class A common stock and adversely affect its value.

On March 4, 2024, we received a notice from Nasdaq that our Class A common stock did not meet the $1.00 minimum bid price required for continued listing on the Nasdaq Capital Market (the “Minimum Bid Price Requirement”). The receipt of this letter does not result in the immediate delisting of the Company’s Class A common stock, and we have an initial period of 180 calendar days (the “Compliance Period”) to regain compliance with the Minimum Bid Price Requirement.

If, at any time during the Compliance Period the bid price closes at $1.00 or more per share for a minimum of 10 consecutive business days (subject to Staff’s discretion to increase the minimum period to up to 20 consecutive business days under certain conditions), the Staff would provide written notification to the Company that it again complies with the Minimum Bid Price Requirement and the Class A common stock will continue to be eligible for listing on the Nasdaq Capital Market unless other eligibility deficiencies exist. However, if our Class A common stock has a closing bid price of $0.10 or less for ten consecutive trading days during the Compliance Period, Nasdaq can issue a Staff Determination Letter, which, unless appealed, would subject our Class A common shares to immediate suspension and delisting. On February 21, 2024, at a special meeting of our stockholders, our stockholders approved a reverse stock split of our common stock at a ratio, ranging from 1:5 to 1:15, with the actual ratio to be determined by our Board of Directors. On March 19, 2024, our Board of Directors approved a final split ratio of 1:10. Following such approval, we filed a certificate of amendment to our Certificate of Incorporation with the Secretary of State of the State of Delaware to effect the 2024 Reverse Split, with an effective time of 11:59, p.m., Eastern Time on March 26, 2024. The liquidity of the shares of our Class A common stock may be affected adversely by the 2024 Reverse Split undertaken to address this Minimum Bid Price Requirement compliance failure, given the reduced number of shares that will be outstanding following the 2024 Reverse Split. In addition, the 2024 Reverse Split may increase the number of stockholders who own odd lots (less than 100shares) of our Class A common stock, creating the potential for such stockholders to experience an increase in the cost of selling shares and greater difficulty effecting such sales.

If the Company were to not regain compliance with the Minimum Bid Price Requirement by the end of the Compliance Period, the Company could be eligible for an additional 180 calendar day compliance period. To qualify, the Company would be required to meet the continued listing requirements for the market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the Minimum Bid Price Requirement, and would need to provide written notice to Nasdaq of its intention to cure the deficiency during the additional compliance period.

If it appears to the Staff that the Company would not be able to cure the deficiency, the Staff will provide written notice to the Company that its Class A common stock will be subject to delisting. At that time, the Company can appeal the Staff’s delisting determination to pay cash dividendsa Nasdaq Hearing Panel (the “Panel”). The Company expects that its Class A common stock would remain listed pending the Panel’s decision. There can be no assurance that, if the Company did appeal the Staff’s delisting determination to the Panel, such appeal would be successful.

In the event of a delisting from the Nasdaq Capital Market, our Class A common stock would likely be traded in the over-the-counter inter-dealer quotation system, more commonly known as the OTC. OTC transactions involve risks in addition to those associated with transactions in securities traded on the securities exchanges, such as the Nasdaq Capital Market, or Exchange-listed stocks. Many OTC stocks trade less frequently and in smaller volumes than Exchange-listed stocks. Accordingly, our Class A common stock would be less liquid than it would be otherwise. Also, the prices of OTC stocks are often more volatile than Exchange-listed stocks. Additionally, many institutional investors are prohibited from investing in OTC stocks, and it might be more challenging to raise capital when needed.

The primary intent for the 2024 Reverse Split is an anticipated increase in the price of our Class A common stock immediately following and resulting from a reverse stock split due to a reduction in the number of issued and outstanding shares of our common stock to help us meet the Minimum Bid Price Requirement. It cannot be assured that the 2024 Reverse Split will result in any sustained proportionate increase in the market price of our Class A common stock, which is dependent upon many factors, including the business and financial performance of the company, general market conditions, and prospects for future success, which are unrelated to the number of shares of our common stock outstanding. It is not uncommon for the market price of a company’s common stock to decline in the period following a reverse stock split.

Our reverse stock split may decrease the liquidity of the shares of our Class A common stock.

On February 21, 2024, at the special meeting, our stockholders approved a reverse stock split of our common stock at a ratio, ranging from 1:5 to 1:15, with the actual ratio to be determined by our Board of Directors. On March 19, 2024, our Board of Directors approved a final split ratio of 1:10 to regain compliance with the Minimum Bid Price Requirement prior to the offering described in this prospectus, with such split being effective on March 26, 2024 at 11:59 Eastern Time. The liquidity of the shares of our Class A common stock may be affected adversely by the 2024 Reverse Split given the reduced number of shares that will be atoutstanding following the discretion2024 Reverse Split. In

addition, the 2024 Reverse Split will increase the number of stockholders who own odd lots (less than 100shares) of our Class A common stock, creating the potential for such stockholders to experience an increase in the cost of selling their shares and greater difficulty effecting such sales.

Following a reverse stock split, the resulting market price of our Class A common stock may not attract new investors, including institutional investors, and may not satisfy the investing requirements of those investors. Consequently, the trading liquidity of our Class A common stock may not improve.

Although we believe that a higher market price of our Class A common stock may help generate greater or broader investor interest, there can be no assurance that a reverse stock split, including the 2024 Reverse Split, will result in a share price that will attract new investors, including institutional investors. In addition, there can be no assurance that the market price of our Class A common stock will satisfy the investing requirements of those investors. As a result, the trading liquidity of our Class A common stock may not necessarily improve.

The dual-class structure of our common stock may adversely affect the trading market for our Class A common stock.

We cannot predict whether our dual class structure will result in a lower or more volatile market price of our Class A common stock or in adverse publicity or other adverse consequences. For example, certain index providers have announced restrictions on including companies with dual class or multi-class share structures in certain of their indexes. Our dual class capital structure could make us ineligible for inclusion in certain indices and mutual funds, exchange-traded funds and other investment vehicles that attempt to passively track these indices will not be investing in our stock. These policies are still fairly new, and it is as of yet unclear what effect, if any, they will have on the valuations of publicly traded companies excluded from the indices, but it is possible that they may depress these valuations compared to those of other similar companies that are included. Furthermore, we cannot assure you that other stock indices will not take a similar approach to S&P, Dow Jones or FTSE Russell in the future. Exclusion from indices could make our Class A common stock less attractive to investors and, as a result, the market price of our Class A common stock could be adversely affected.

Holders of our Class B common stock control the direction of our business and their ownership of our common stock can prevent other stockholders from influencing significant decisions.

As of, 2024, two holders of our Class B common stock, Joshua M. Hare, co-founder, Chief Science Officer and Chairman of the Board of Directors, and Donald M. Soffer, co-founder and former member of our Board of Directors, control voting rights over approximately            % of the combined voting power of our Class A common stock and Class B common stock. For so long as holders of Class B common stock continue to hold their shares, they will be dependent uponable to significantly influence or effectively control the composition of our consolidated financial condition, resultsBoard of operations, capital requirementsDirectors and the approval of actions requiring stockholder approval through their voting power. Accordingly, for such period of time, these holders will have significant influence with respect to our management, business plans and policies. In particular, for so long as the Class B common stock remains outstanding, the holders may be able to cause or prevent a change of control of our Company or a change in the composition of our Board of Directors and could preclude any unsolicited acquisition of our Company. The concentration of ownership could deprive stockholders of an opportunity to receive a premium for shares of Class A common stock as part of a sale of our Company and ultimately might affect the market price of our Class A common stock.

If securities or industry analysts do not publish research or reports, or if they publish negative, adverse, or misleading research or reports, regarding us, our business or our market, our Class A common stock price and trading volume could decline.

The trading market for our Class A common stock is influenced by the research and reports that securities or industry analysts publish about us, our business, or our market. We do not currently have significant research coverage and may never obtain significant research coverage by securities or industry analysts. If no or few securities or industry analysts provide coverage of us, the Class A common stock price could be negatively impacted. In the event we obtain significant, or any securities or industry analyst coverage and such coverage is negative, or adverse or misleading regarding us, our business model, our intellectual property, our stock performance or our market, or if our operating

results fail to meet the expectations of analysts, our Class A common stock price would likely decline. If one or more of these analysts cease coverage of us or fail to publish reports on us regularly, we could lose visibility in the financial markets, which in turn could cause our Class A common stock price or trading volume to decline.

FINRA sales practice requirements may limit a stockholder’s ability to buy and sell our securities.

Effective June 30, 2020, the SEC implemented Regulation Best Interest requiring that “A broker, dealer, or a natural person who is an associated person of a broker or dealer, when making a recommendation of any securities transaction or investment strategy involving securities (including account recommendations) to a retail customer, shall act in the best interest of the retail customer at the time the recommendation is made, without placing the financial or other factors asinterest of the broker, dealer, or natural person who is an associated person of a broker or dealer making the recommendation ahead of the interest of the retail customer.” This is a significantly higher standard for broker-dealers to recommend securities to retail customers than before under prior FINRA suitability rules. FINRA suitability rules do still apply to institutional investors and require that in recommending an investment to a customer, a broker-dealer must have reasonable grounds for believing that the investment is suitable for that customer. Prior to recommending securities to their customers, broker-dealers must make reasonable efforts to obtain information about the customer’s financial status, tax status, investment objectives and other information, and, for retail customers, determine that the investment is in the customer’s “best interest,” and meet other SEC requirements. Both SEC Regulation Best Interest and FINRA’s suitability requirements may make it more difficult for broker-dealers to recommend that their customers buy speculative, low-priced securities. They may affect investing in our Class A common stock, which may have the effect of reducing the level of trading activity in our securities. As a result, fewer broker-dealers may be willing to make a market in our Class A common stock, reducing a stockholder’s ability to resell shares of our Class A common stock.

Provisions in our certificate of incorporation and bylaws and Delaware law might discourage, delay or prevent a change in control of our company or changes in our management and, therefore, depress the market price of our Class A common stock.

Our certificate of incorporation and bylaws contain provisions that could depress the market price of our Class A common stock by acting to discourage, delay or prevent a change in control of our company or changes in our management that the stockholders of our company may deem advantageous. These provisions, among other things:

•establish a classified Board of Directors so that not all members of our Board are elected at one time;

•permit only the Board of Directors deems relevant.to establish the number of directors and fill vacancies on the Board;

•provide that directors may only be removed “for cause” and only with the approval of two-thirds of our stockholders;

•provide for a dual class common stock structure, which provides certain affiliates of ours, including our co-founder and members of our Board, individually or together, with the ability to significantly influence the outcome of matters requiring stockholder approval, even if they own significantly less than a majority of the shares of our outstanding common stock and Class B common stock;

•authorize the issuance of “blank check” preferred stock that our Board could use to implement a stockholder rights plan (also known as a “poison pill”);

•eliminate the ability of our stockholders to call special meetings of stockholders;

•prohibit stockholder action by written consent, which requires all stockholder actions to be taken at a meeting of our stockholders;

•prohibit cumulative voting;

•authorize our Board to amend our bylaws;

•establish advance notice requirements for nominations for election to our Board or for proposing matters that can be acted upon by stockholders at annual stockholder meetings; and

•require a super-majority vote of stockholders to amend some of the provisions described above.

We have a history of losses, may not be able to achieve profitability going forward, and may not be able to raise additional capital necessary to continue as a going concern.

We have experienced significant losses since inception and, at December 31, 2023 and 2022, had an accumulated deficit of approximately $85.0 million and $62.8 million, respectively. We expect to incur additional losses in the future and expect the cumulative losses to increase. We expect our operating expenses to increase and it is not likely that our grant revenues will fully fund our clinical programs.

As of December 31, 2023, we had cash and cash equivalents of $4.9 million and marketable securities of $0.4 million. We have prepared a cash flow forecast which indicates that we will only have sufficient cash to fund our operating expenses and capital expenditure requirements into the second quarter of 2024. As a result, we will need to raise additional capital to continue as a going concern. There are no assurances that we would be able to raise additional capital or on terms favorable to us. Our recurring losses from operations and negative cash flow raise substantial doubt about our ability to continue as a going concern without sufficient capital resources and we have included an explanatory paragraph in the notes to our financial statements for the year ended December 31, 2023, with respect to this uncertainty. Further, the report of our independent registered public accounting firm with respect to our audited financial statements for the year ended December 31, 2023 included an emphasis of matter paragraph stating that our recurring losses from operations and continued cash outflows from operating activities raised substantial doubt about our ability to continue as a going concern. Our consolidated financial statements do not include any adjustments that might result from the outcome of this going concern uncertainty and have been prepared under the assumption that we will continue to operate as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business.

If we are unable to continue as a going concern, we may be forced to liquidate our assets, which would have an adverse impact on our business and developmental activities. In such a scenario, the values we receive for our assets in liquidation or dissolution could be significantly lower than the values reflected in our financial statements. The reaction of investors to the inclusion of a going concern statement by our independent registered public accounting firm and our potential inability to continue as a going concern may materially adversely affect our stock price and our ability to raise new capital. Our ability to continue as a going concern is dependent on our available cash, how well we manage that cash, and our operating requirements. If we are unable to raise additional capital when needed, we would be forced to delay, reduce or eliminate our clinical trial programs, commercialization efforts and other business activities.

USE OF PROCEEDS

We estimate that the net proceeds we will receive from the sale of our securities in this offering, assuming all the securities we are offering are sold, after deducting placement agent fees and other estimated offering expenses payable by us, and assuming no sale of any pre-funded warrants and no exercise of the Class A common warrants being issued in this offering, will be approximately $            , based on an assumed combined public offering price of $            per share and accompanying Class A common warrant, which was the closing price for our Class A common stock on the Nasdaq Capital Market on            , 2024.

However, because this is a best efforts offering and there is no minimum offering amount required as a condition to the closing of this offering, the actual offering amount, the placement agent fees and net proceeds to us are not presently determinable and may be substantially less than the maximum amounts set forth on the cover page of this prospectus, and we may not sell any or all of the securities we are offering. As a result, we may receive significantly less in net proceeds.

The following table presents our estimated net proceeds if 100%, 75%, 50% or 25% of the securities in this offering are sold.

We have based the estimates in the above table on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect. The net proceeds from this offering.offering are not expected to be sufficient to fund advancement of any of our therapeutic candidates through regulatory approval. We will not receive any of the proceeds from the sale or other dispositionneed to raise substantial additional funds to complete development and commercialization of our Common Stock by the Selling Stockholders pursuant to this prospectus. However, wetherapeutic candidates which development or commercialization may receive proceeds in the aggregate of up to approximately $8.3 million if all of the Warrants covered by this prospectus are exercised for cash, based on the per share exercise price of the Warrants. not be successful.

We cannot predict when, or if, the Warrants will be exercised. It is possible that the Warrants may expire and may never be exercised for cash.

Wecurrently intend to use anythe net proceeds from the exercise of the Warrantsthis offering for our ongoing clinical and regulatory development of Lomecel-B™Lomecel-B™ for the treatment of several disease states and indications, including HLHS and Alzheimer’s Disease, and the ongoing and prospective clinical studies of Lomecel-B™ for the treatment of Aging-related Frailty study being conducted in Japan;Disease; obtaining regulatory approvals; capital expenditures, working capital and other general corporate purposes. We are subject to substantial risks that could require us to obtain additional funding in order to achieve these objectives. See “Risk Factors.” We may need substantial additional capital in the future, which could cause dilution to our existing stockholders, restrict our operations or require us to relinquish rights, and if additional capital is not available, we may have to delay, reduce or cease operations.

Our expected use of anynet proceeds from the exercise of the Warrantsthis offering represents our current intentions based upon our present plans and business condition. The amounts and timing of our actual use of anynet proceeds will vary depending on numerous factors, including our ability to obtain additional financing, the relative success and cost of clinical and regulatory development programs and the amount and timing of product revenue, if any. In addition, we might decide to postpone or not pursue certain activities if, among other factors, the net proceeds from the exercise of the Warrantsthis offering and our other sources of cash are less than expected. As a result, management will have broad discretion in the application of the anynet proceeds, from the exercise of the Warrants, and investors will be relying on our judgment regarding the application of suchthe net proceeds. Pending the uses described above, we intend to invest the anynet proceeds in interest-bearing investment-gradeinterest-bearing investment-grade securities or deposits.

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Table of Contents

The Selling Stockholders will pay any underwriting discounts and commissions and expenses incurred bySELECTED FINANCIAL DATA

2024 Reverse Split

On March 19, 2024, our Board approved a 1:10 reverse stock split of our common stock. Following such approval, we filed a certificate of amendment to our Certificate of Incorporation with the Stockholders for brokerage, accounting, tax or legal services or any other expenses incurred by the Selling Stockholders in disposingSecretary of State of the securities covered by this prospectus. WeState of Delaware to effect the 2024 Reverse Split, with an effective time of 11:59, p.m. Eastern Time on March 26, 2024. The 2024 Reverse Split will bearhave the costs, fees and expenses incurred in effectingeffect of reducing the registrationaggregate number of the securities covered by this prospectus, including all registration and filing fees, and fees and expenses of our counsel and our independent registered public accountants.

DETERMINATION OF OFFERING PRICE

We cannot currently determine the price or prices at which theoutstanding shares of our Common StockClass A common stock on a pre-reverse split basis from 10,295,426 to a total of 1,029,543 on a post-reverse split basis, and the aggregate number of outstanding shares of our Class B common stock on a pre-reverse split basis from 14,839,993 to 1,484,000 on a post-reverse split basis, subject to rounding up of fractional shares resulting from the 2024 Reverse Split. The number of authorized shares of the Company’s common stock will remain unchanged at 105,000,000 shares, consisting of 84,295,000 shares of Class A common stock, 15,705,000 shares of Class B common stock and 5,000,000 shares of preferred stock.

The following selected financial data has been derived from our audited financial statements included in our Annual Report on Form 10-K filed with the SEC on February 27, 2024, as amended on Form 10-K/A filed with the SEC on March 11, 2024, as adjusted to reflect the 2024 Reverse Split for all periods presented.

Our historical results are not indicative of the results that may be soldexecuted in the future, and results of interim periods are not indicative of the results for the entire year.

As Reported

As Adjusted For the 2024 Reverse Split

DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock. We intend to retain all available funds and future earnings, if any, for development and expansion of our business. Any future determination regarding the declaration and payment of dividends, if any, will be at the discretion of our Board of Directors and will depend on then-existing conditions, including our financial condition, operating results, contractual restrictions, capital requirements, business prospects and other factors our Board of Directors deems relevant. Investors should not purchase our Class A common stock with the expectation of receiving cash dividends.

DILUTION

If you invest in our securities in this offering, your ownership interest may be diluted immediately depending on the difference between the effective public offering price per share of our Class A common stock (assuming the exercise for cash of all pre-funded warrants issued in this offering) and the as adjusted net tangible book value per share of our Class A common stock immediately after this offering (assuming the exercise for cash of all pre-funded warrants issued in this offering).

At December 31, 2023, we had a net tangible book value of $3.0 million or $0.1211 per share. Net tangible book value per share represents our total tangible assets (total assets less intangible assets) less total liabilities at a particular date, divided by the Selling Stockholders under this prospectus.

THE SELLING STOCKHOLDERS

Thetotal number of our outstanding shares of Common StockClass A common stock as of that date.

After giving effect to the sale and issuance ofshares of Class A common stock and accompanying Class A common warrants in this offering, at an assumed combined public offering price of $    per share and accompanying Class A common warrant, based on the closing price of our Class A common stock on the Nasdaq Capital Market on   , 2024, assuming no sale of any pre-funded warrants in this offering, no exercise of any of the Class A common warrants being offered by the Selling Stockholders are those issuable to the Selling Stockholders uponin this offering, no exercise of the Warrants. For additional information regardingPlacement Agent Warrants to be issued to the Offeringsplacement agent or its designees as compensation in connection with this offering, and after deducting placement agent fees and estimated offering expenses payable by us, our as adjusted net tangible book value as of December 31, 2023, would have been approximately $            , or $            per share of our Class A common stock. This represents an immediate increase in as adjusted net tangible book value of approximately $            per share to our existing stockholders and an immediate decrease in such measure of $            per share to new investors.

The dilution to investors participating in this offering is determined by subtracting the as adjusted net tangible book value per share after this offering from the effective public offering price per share paid by investors participating in this offering. The actual combined public offering price will be determined through negotiation between us, the placement agent and the issuanceinvestors in the offering and may be at a discount to the current market price. Therefore, the assumed public offering price used throughout this prospectus may not be indicative of the Warrants, see “Prospectus Summary – Selling Stockholders Overview – Private Placement of Warrants.” We are registering the Registered Securities in order to permit the Selling Stockholders to offer the Common Stock for resale from time to time. Except for the ownership of the Warrants, the Engagement Letter with Wainwright, and the Purchaser’s purchase of certain warrants and shares of our Common Stockfinal public offering price. The following table illustrates this result on a per share basis:

A $0.10 increase in the Company’s December 2021 PIPEassumed combined public offering price per share and accompanying Class A common warrant would increase the Selling Stockholders have not had any material relationship with us withinas adjusted net tangible book value by $ per share and result in dilution to investors participating in this offering of $     per share, and a $0.10 decrease in the past three years.

The table below listsassumed combined public offering price per share and accompanying Class A common warrant would decrease the Selling Stockholdersas adjusted net tangible book value by $    per share and other information regarding the beneficial ownership of our Common Stockresult in dilution to investors participating in this offering by $   per share, in each of the Selling Stockholders. The second column listscase assuming the number of shares offered by us, as set forth on the cover page of Common Stock beneficially owned by each Selling Stockholder, based on its or his beneficial ownershipthis prospectus, remains the same and assuming no pre-funded warrants are sold in this offering, no exercise of the Warrants and our Common Stock, as of November 13, 2023, assuming exercise of all Warrants held by such Selling Stockholder on that date, without regard to any limitations on exercise. The third column lists the shares of Common StockClass A common warrants being offered underin this prospectusoffering, that no value is attributed to such Class A common warrants and that such Class A common warrants are classified as and accounted for as equity, and after deducting placement agent fees and estimated expenses payable by the Selling Stockholders.us.

This prospectus generally covers the resaleAn increase of            shares in the maximum number of shares offered by us in this offering would increase our as adjusted net tangible book value per share by approximately $            and our as adjusted net tangible book value per share would be $            , representing an increase in as adjusted net tangible book value per share to new investors in this offering of Common Stock$     . A decrease of shares in the number of shares offered by us in this offering would decrease our as adjusted net tangible book value per share by approximately $     resulting in an as adjusted net tangible book value per share of $    and an increase in as adjusted net tangible book value per share to investors participating in this offering of $   per share. The foregoing calculations assume that the combined public offering price remains the same, and are after deducting placement agent fees and estimated expenses payable by us.

The table and discussion above are based on 2,510,730shares of Class A common stock and Class B common stock outstanding at December 31, 2023 (as adjusted for the 2024 Reverse Split and subject to adjustment based on issuances of additional shares as applicable due to the rounding up of fractional shares resulting from the 2024 Reverse Split), and exclude, as of that date, the following:

•5,534shares of Class A common stock issuable upon exercise of the Warrants, determined as if the outstanding Warrants were exercised in full aswarrants at an exercise price of the trading day immediately preceding the date the registration statement$120.00 per share;

•116,929shares of which this prospectus forms a part was initially filed with the SEC, without regard to any limitations onClass A common stock issuable upon the exercise of the Warrants. The fourth column assumes the saleoutstanding warrants at an exercise price of all of the $52.50 per share;

•4,678shares of Common Stock offered byClass A common stock issuable upon the Selling Stockholders pursuant to this prospectus. The percentageexercise of beneficial ownership in the fourth column represents the percentageoutstanding warrants at an exercise price of the outstanding $175.00 per share;

•484,850shares of both the Common Stock and the Company’s Class B Common Stock.

Under the terms of the Warrants, a Selling Stockholder may not exercise any portion of the Warrants to the extent such exercise would cause the Selling Stockholder to own more than 4.99% of the Company’s outstanding Common Stock immediately after giving effect to the issuance of shares of Common StockA common stock issuable upon exercise of such Warrant. A Selling Stockholder may decrease or, uponoutstanding October private placement warrants at least 61 days’ prior notice to us, increase such limitation. In no event shall such beneficial ownership limitation exceed 9.99%. The Private Placement Warrants are not exercisable until our stockholders approve the issuancean exercise price of the Private Placement Warrants and the $16.50 per share;

•16,970shares of Common StockClass A common stock issuable upon exercise of outstanding October placement agent warrants at an exercise price of $20.625 per share;

•135,531shares of Class A common stock issuable upon the exercise thereof. The number of outstanding December private placement warrants at an exercise price of $16.00 per share;

•9,488shares of Common Stock in the columns below does not reflect these limitations. The Selling Stockholders may sell all, some or none of their shares of Common Stock in this offering. See “Plan of Distribution.”

PLAN OF DISTRIBUTION

We are registering the Registered Securities on behalf of the Selling Stockholders. Each of the Selling Stockholders and any of their pledgees, assignees, distributees and successors-in-interest of the Registered Securities received after the date of this prospectus from a Selling Stockholder as a gift, pledge, or other transfer, may, from time to time, sell, transfer, or otherwise dispose of any or all of the shares of Common Stock covered hereby on The Nasdaq Capital Market or any other stock exchange, market or trading facility on which the securities are traded or in private transactions. These dispositions may be at fixed prices, at prevailing market prices at the time of the sale, at varying prices determined at the time of sale, or at negotiated prices. A Selling Stockholder may use any one or more of the following methods when selling securities:

The Selling Stockholders may also sell securities under Rule 144 or any other exemption from registration under the Securities Act of 1933, as amended (the “Securities Act”), if available, rather than under this prospectus.

Broker-dealers engaged by the Selling Stockholders may arrange for other brokers-dealers to participate in sales. Broker-dealers may receive commissions or discounts from the Selling Stockholders (or, if any broker-dealer acts as agent for the purchaser of securities, from the purchaser) in amounts to be negotiated, but, except as set forth in a supplement to this prospectus, in the case of an agency transaction not in excess of a customary brokerage commission in compliance with FINRA Rule 2121; and in the case of a principal transaction a markup or markdown in compliance with FINRA Rule 2121.

In connection with the sale of the Registered Securities or interests therein, the Selling Stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the Registered Securities in the course of hedging the positions they assume. To the extent permitted by applicable securities laws, the Selling Stockholders may also sell the Registered Securities short and deliver these securities to close out their short positions, or loan or pledge the Registered Securities to broker-dealers that in turn may sell these securities. The Selling Stockholders may also enter into option or other transactions with broker-dealers or other financial institutions or the creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of the Registered Securities offered by this prospectus, which Registered Securities such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The Selling Stockholders and any underwriters, broker-dealers or agents that participate in the sale of the Registered Securities or interests therein may be “underwriters” within the meaning of the Securities Act. In such event, any discounts, commissions, concessions or profit they earn on any resale of the Registered Securities purchased by them and covered by this prospectus may be deemed to be underwriting discounts and commissions under the Securities Act. Selling Stockholders who are “underwriters” within the meaning of the Securities Act will be subject to the prospectus delivery requirements of the Securities Act. Each Selling Stockholder has informed the Company that it does not have any written or oral agreement or understanding, directly or indirectly, with any person to distribute the Registered Securities.

The Company has agreed to indemnify the Selling Stockholders against certain losses, claims, damages, and liabilities, including liabilities under the Securities Act.

We have agreed to keep the registration statement of which this prospectus is a part effective until the Purchaser no longer owns any Private Placement Warrants or shares of Common Stock issuable upon the exercise thereof. The Registered Securities willof outstanding December placement agent warrants at an exercise price of $21.813 per share;

•203,614shares of Class A common stock reserved for future issuance under our 2021 Equity Incentive Plan (the “2021 Plan”);

•8,059shares issuable upon the vesting of RSUs under the Company’s 2021 Plan;

•12,500shares issuable upon the vesting of PSUs under the Company’s 2021 Plan; and

•42,191 stock options outstanding with an average exercise price of $48.60 issuable under the Company’s 2021 Plan.

Except as otherwise indicated herein, all information in this prospectus assumes the following:

•no exercise of outstanding options or warrants;

•no exercise of the placement agent’s warrants to purchase            shares to be sold only through registeredissued upon consummation of this offering at an exercise price of $            per share, equal to 125% of the combined public offering price of the Class A common stock and the accompanying Class A common warrants; and

•the exercise for cash of all pre-funded warrants issued in this offering.

To the extent that outstanding options or licensed brokerswarrants are exercised, or dealers if requiredshares are issued under applicable state securities laws.our equity incentive plans, you may experience dilution. In addition, in certain states,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 Registered Securities covered hereby may not be sold unless they have been registered or qualified for saleextent that, in the applicable statefuture, additional capital is raised through the sale of equity, convertible debt securities, or an exemption from the registration or qualification requirement is available and is complied with.

Under applicable rules and regulations under the Exchange Act, any person engagedsecurities with equity components, those issuances may result in the distribution of the Registered Securities may not simultaneously engage in market making activities with respectdilution to our Common Stock for the applicable restricted period, as defined in Regulation M, prior to the commencementstockholders.

Cashless Exercise

If at the time a holder exercises its 2021 Warrant, aof exercise there is no effective registration statement registering, or the issuance of the shares of Common Stock underlying the 2021 Warrants under the Securities Act of 1933, as amended (the “Securities Act”) is not then effective or available and an exemption from registration under the Securities Actprospectus contained therein is not available for the issuance of suchthe underlying shares thento the holder, in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of Common StockClass A common stock determined according to a formula set forth in the 2021 Warrant.Class A common warrants.

Fundamental Transactions

Limitations on Exercise. With respectIn the event of a fundamental transaction, as described in the Class A common warrants and generally including any reorganization, recapitalization or reclassification of our Class A common stock, the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person, the acquisition of more than 50% of our outstanding Class A common stock, or any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding Class A common stock, the holders of the Class A common warrants will be entitled to receive upon exercise of the PIPE Warrants,Class A common warrants the kind and amount of securities, cash or other property that the holders would have received had they exercised the Class A common warrants immediately prior to such fundamental transaction. In addition, in certain circumstances, upon a fundamental transaction, the holder (together withof a Class A common warrant will have the right to require us to repurchase its affiliates) mayClass A common warrants at the Black-Scholes value; provided, however, that, if the fundamental transaction is not exercise anywithin our control, including not approved by our Board, then the holder will only be entitled to receive the same type or form of consideration (and in the same proportion), at the Black-Scholes value of the unexercised portion of the PIPE WarrantClass A common warrant that is being offered and paid to the extent that the holder would own more than 4.99% (or 9.99%, at the election of the warrant holder) of the outstanding Common Stock after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s warrants up to 9.99% of the number of sharesholders of our Common Stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the PIPE Warrants.

No Fractional Shares. No fractional shares of Common Stock will be issuedClass A common stock in connection with the exercise of a 2021 Warrant. In lieu of fractional shares, we will (i) round up or down to the next whole share, in the case of the IPO Underwriter Warrants, or (ii) either pay a cash adjustment in respect of such fractional amount or round up to the next whole share, in the case of the PIPE Warrants.fundamental transaction.

Transferability

Rights as a Stockholder. Except as otherwise provided in the 2021 Warrants or by virtue of such holder’s ownership of shares of our Common Stock, the holders of the 2021 Warrants do not have the rights or privileges of holders of our Common Stock, including any voting rights, unless and until they exercise their 2021 Warrants.

Waivers and Amendments. Subject to certain exceptions, any term of the 2021 Warrants may be amended, modified, or waived with our written consent and the written consent of the holder of such 2021 Warrant.

Failure to Timely Deliver Securities. With respect to the PIPE Warrants, upon exercise of the PIPE Warrant by the holder, if the Company or its transfer agent, Colonial Stock Transfer Company, Inc., fails to deliver the securities to holder by the required share delivery date set forth in the PIPE Warrant, or if the Company did not provide the required notice to holder thatapplicable laws, a registration statement covering the issuance of theClass A common warrant shares subject to the exercise notice is not available and the Company is unable to deliver the securities without any restrictive legend, then generally, the holder may rescind the exercise in whole or in part or may require the Company to pay to the holder an amount in cash to make the investor whole in connection with the Company’s failure to timely deliver securities.

The Private Placement Warrants

In the Private Placement concurrent with our October 2023 Registered Direct Offering, we issued Private Placement Warrants to an institutional accredited investor to purchase up to 4,848,486 shares of our Common Stock at an exercise price of $1.65 per share, consisting of (i) Series A Warrants to purchase up to 2,424,243 shares of our Common Stock and Series B Warrants to purchase 2,424,243 shares of our Common Stock. The terms of the Series A Warrants and Series B Warrants are identical, except as to duration. The following summary of certain terms and provisions of the Private Placement Warrants is not complete, is subject to, and qualified in its entirety by, the provisions of the Private Placement Warrants, the forms of which are filed as exhibits to the registration statement of which this prospectus forms a part.

Exercise Price and Duration. Each Private Placement Warrant is exercisable for one share of Common Stock. The Private Placement Warrants have an exercise price of $1.65 per share and are exercisable upon the Stockholder Approval Date. The Series A Warrants will expire five and one-half years from the date of issuance on April 13, 2029. The Series B Warrants will expire eighteen months from the date of issuance on April 14, 2025.

Exercisability. The Private Placement Warrants are not exercisable until our stockholders approve the issuance of the Private Placement Warrants and the shares Common Stock issuable upon the exercise thereof (the “Stockholder Approval”). Once exercisable, the Private Placement Warrants may be exercised, at the option of each holder, in whole or in part by delivering to us a duly executed exercise notice and, at any time a registration statement registering the issuance of the shares of Common Stock underlying the Private Placement Warrants under the Securities Act is effective and available for the issuance of such shares, by payment in full in immediately available funds for the number of shares of Common Stock purchased upon such exercise.

Cashless Exercise. If, at the time a holder exercises its Private Placement Warrants, a registration statement registering the issuance of the shares of Common Stock underlying the Private Placement Warrants is not then effective or the prospectus contained therein is not available for the resale of such shares by the holder, then the Private Placement Warrants may be exercised in whole or in part, by means of a cashless exercise, in which case the holder would receive upon such exercise the net number of shares of Common Stock determined according to the formula set forth in the Private Placement Warrants.

Exercise Limitation. A holder of Private Placement Warrants will not have the right to exercise any portion thereof if the holder, together with its affiliates, would beneficially own in excess of 4.99% of the number of shares of our Common Stock outstanding immediately after giving effect to such exercise; provided, however, that the holder may elect to decrease, or upon at least 61 days’ prior notice to the Company, increase such beneficial ownership limitation. In no event shall such beneficial ownership limitation exceed 9.99%.

Transferability. Subject to compliance with any applicable securities laws, the Private Placement Warrants may be transferred at the option of the holder upon surrender of the warrant(s)Class A common warrants to us together with the appropriate instruments of transfer.

Fractional Shares.

No fractional shares of Common StockClass A common stock will be issued upon the exercise of the Private Placement Warrants. AsClass A common warrants. Rather, the number of shares of Class A common stock to any fraction of a share which the holder would otherwise be entitled to purchase upon such exercise, we shall,issued will, at our election, either be rounded up to the nearest whole number or we will pay a cash adjustment in respect of such final fraction in an amount equal to such fraction multiplied by the exercise price or round up to the next whole share.price.

Trading Market.

There is no established public trading market for the Private Placement Warrants,Class A common warrants, and we do not expect a market to develop. The Private Placement Warrants areWe do not listedintend to apply for a listing of the Class A common warrants on any securities exchange or other nationally recognized trading system. Without an active trading market, the liquidity of the Private Placement Warrants isClass A common warrants will be limited.

Fundamental Transactions. If a Fundamental Transaction (as defined in the Private Placement Warrants, but generally including the sale, transfer or other disposition of all or substantially all of our assets, our consolidation or merger with or into another person or reorganization, recapitalization or reclassification or the acquisition of our outstanding Common Stock which results in any person or group acquiring 50% or more of the voting power of our The Class A common equity) occurs, then the successor entity will succeed to, and be substituted for us, and may exercise every right and power that we may exercise and will assume all of our obligations under the Private Placement Warrants with the same effect as if such successor entity had been named in the Private Placement Warrants themselves. If holders of shares of our Common Stock are given a choice as to the securities, cash, or property to be received in such a Fundamental Transaction, then the holder shall be given the same choice as to the consideration it would receivestock issuable upon any exercise of the Private Placement Warrants following such a Fundamental Transaction. Additionally, as more fully described in the Private Placement Warrants, in the event of certain Fundamental Transactions, the holders of Private Placement Warrants will be entitled to receive consideration in an amount equal to the Black Scholes value of the Private Placement WarrantsClass A common warrants is currently listed on the date of consummation of such Fundamental Transaction.Nasdaq.

Rights as a Stockholder.

Except as otherwise provided in the Private Placement WarrantsClass A common warrants or by virtue of such holder’sthe holders’ ownership of our shares of Common Stock,Class A Class A common stock, the holderholders of a Private Placement Warrant doesthe Class A common warrants do not have the rights or privileges of a holderholders of our Common Stock,shares of Class A common stock, including any voting rights, until such Common Warrant holders exercise their Class A common warrants.

Waivers and Amendments

No term of the holder exercises the Private Placement Warrant.

Amendment and Waiver. Private Placement WarrantsClass A common warrants may be modified or amended or the provisions thereof waived withwithout the written consent of the Company andmajority of the respective holder.holders of the Class A common warrants purchased in this offering.

PLAN OF DISTRIBUTION

Pursuant to an engagement agreement dated, 2024 (the “Engagement Agreement”), we have engaged   to act as our exclusive placement agent to solicit offers to purchase the shares of our Class A common stock, Class A common warrants and pre-funded warrants offered by this prospectus. The placement agent is not purchasing or selling any such securities, nor is it required to arrange for the purchase and sale of any specific number or dollar amount of such securities, other than to use its “reasonable best efforts” to arrange for the sale of such securities by us. Therefore, we may not sell all of the shares of Class A common stock, Class A common warrants and pre-funded being offered. The terms of this offering were subject to market conditions and negotiations between us, the placement agent and prospective investors. The placement agent will have no authority to bind us by virtue of the Engagement Agreement. This is a best efforts offering and there is no minimum offering amount required as a condition to the closing of this offering. The placement agent may retain sub-agents and selected dealers in connection with this offering.

Investors purchasing securities offered hereby will have the option to execute a securities purchase agreement with us. In addition to rights and remedies available to all purchasers in this offering under federal securities and state law, the purchasers which enter into a securities purchase agreement will also be able to bring claims of breach of contract against us. The ability to pursue a claim for breach of contract is material to larger purchasers in this offering as a means to enforce the following covenants uniquely available to them under the securities purchase agreement: (i) a covenant to not enter into variable rate financings for a period offollowing the closing of the offering, subject to an exception; and (ii) a covenant to not enter into any equity financings for   from closing of the offering, subject to certain exceptions.

The nature of the representations, warranties and covenants in the securities purchase agreements shall include:

•standard issuer representations and warranties on matters such as organization, qualification, authorization, no conflict, no governmental filings required, current in SEC filings, no litigation, labor or other compliance issues, environmental, intellectual property and title matters and compliance with various laws such as the Foreign Corrupt Practices Act; and

•covenants regarding matters such as registration of warrant shares, no integration with other offerings, filing of an 8-K to disclose entering into these securities purchase agreements, no shareholder rights plans, no material nonpublic information, use of proceeds, indemnification of purchasers, reservation and listing of Class A common stock, and no subsequent equity sales for            .

Delivery of the shares of Class A common stock, Class A common warrants and pre-funded warrants offered hereby is expected to occur on or about            , 2024, subject to satisfaction of certain customary closing conditions.

We have agreed to pay the placement agent a total cash fee equal to% of the gross proceeds received in the offering and a management fee equal to   % of the gross proceeds raised in the offering. We will also pay the placement agent for non-accountable fees and expenses of up to $            , and its legal fees and expenses and other corporate purposes, couldout-of-pocket expenses in an amount up to $

In addition, we have agreed to issue to the effectplacement agent and its designees the Placement Agent Warrants to purchase that number of making it more difficultshares of our Class A common stock equal to % of the aggregate number of shares of Class A common stock (or Class A common stock equivalents) issued in this offering at an exercise price of $     (equal to    % of the assumed combined public offering price per share of Class A common stock and Class A common warrant) and will terminate on the   anniversary of commencement of sales in this offering. The Placement Agent Warrants are registered by the registration statement of which this prospectus is a part. The form of the Placement Agent Warrants is included as an exhibit to this registration statement of which this prospectus forms a part.

The Placement Agent Warrants provide for customary anti-dilution provisions (for share dividends, splits and recapitalizations and the like) consistent with FINRA Rule 5110. Pursuant to FINRA Rule 5110(e), the Placement Agent Warrants and any shares issuable thereunder shall not be sold, transferred, assigned, pledged, or hypothecated, or be the subject of any hedging, short sale, derivative, put or call transaction that would result in the effective economic disposition of the securities by any person for a third-partyperiod of 180 days immediately following the date of commencement of sales of this offering, except the transfer of any security: (i) by operation of law or by reason of reorganization of the issuer; (ii) to acquire,any FINRA member firm participating in the offering and the officers, partners, registered persons or could discourage a third-party from seekingaffiliates thereof, if all securities so transferred remain subject to acquire, a majoritythe lock-up restriction set forth above for the remainder of the time period; (iii) if the aggregate amount of our outstanding voting stock. There aresecurities held by the placement agent or related

persons does not exceed 1% of the securities being offered; (iv) that is beneficially owned on a pro-rata basis by all equity owners of an investment fund, provided that no participating member manages or otherwise directs investments by the fund and the participating members in the aggregate do not own more than 10% of the equity in the fund; (v) the exercise or conversion of any security, if all securities remain subject to the lock-up restriction set forth above for the remainder of the time period; (vi) if we meet the registration requirements of Forms S-3, F-3 or F-10; or (vii) back to us in a transaction exempt from registration under the Securities Act.

We estimate the total expenses of this offering paid or payable by us, exclusive of the placement agent’s cash fee of     % of the gross proceeds and expenses, will be approximately $ million. After deducting the fees due to the placement agent and our estimated expenses in connection with this offering, we expect the net proceeds from this offering will be approximately $     million (based on an assumed combined public offering price per share and accompanying Class A common warrant of $    which was the last reported sales price of our Class A common stock on the Nasdaq Capital Market on   , 2024.

The following table shows the per share and total cash fees we will pay to the placement agent in connection with the sale of the Class A common stock, Class A common warrants and pre-funded warrants pursuant to this prospectus.

Indemnification

We have agreed to indemnify the placement agent against certain liabilities, including liabilities under the Securities Act and liabilities arising from breaches of representations and warranties contained in our engagement letter with the placement agent. We have also agreed to contribute to payments the placement agent may be required to make in respect of such liabilities.

Lock-up Agreements

We and each of our officers and directors have agreed with the placement agent to be subject to a lock-up period of            days following the date of closing of the offering pursuant to this prospectus. This means that, during the applicable lock-up period, we and such persons may not offer for sale, contract to sell, sell, distribute, grant any option, right or warrant to purchase, pledge, hypothecate or otherwise dispose of, directly or indirectly, any of our shares of preferredClass A common stock currently outstanding,or any securities convertible into, or exercisable or exchangeable for, shares of Class A common stock, subject to customary exceptions. The placement agent may waive the terms of these lock-up agreements in its sole discretion and without notice. In addition, we have agreed to not issue any securities that are subject to a price reset based on the trading prices of our Class A common stock or upon a specified or contingent event in the future or enter into any agreement to issue securities at a future determined price for a period of            following the closing date of this offering, subject to an exception. The placement agent may waive this prohibition in its sole discretion and without notice.

Right of First Refusal

We have granted the placement agent a right of first refusal, subject to an exception, for a period of twelve months following the closing of this offering, to act as exclusive financial advisor, sole book-running manager, sole underwriter, sole placement agent or sole agent for each and every future debt financing or refinancing and public or private equity offering or acquisition or disposition by us or any of our successors or subsidiaries when we seek a financial advisor, book-running manager, underwriter or placement agent. Notwithstanding anything to the contrary contained in this paragraph, in accordance with FINRA Rule 5110(g)(6)(A)(i), any such right of first refusal described in this paragraph shall not have a duration of more than three years from the commencement of sales of the first Offering or the termination date of the term of the Engagement Agreement.

Tail

We have also agreed to pay the placement agent a tail fee equal to the cash and warrant compensation in this offering, if any investor, subject to certain exceptions, who with our written approval was contacted or introduced to us by the placement agent during the term of its engagement, provides us with capital in any public or private offering or other financing or capital raising transaction during the 12-month period following expiration or termination of the Engagement Agreement, subject to certain exceptions.

Other Relationships

From time to time, the placement agent may provide in the future various advisory, investment and commercial banking and other services to us in the ordinary course of business, for which they have received and may continue to receive customary fees and commissions. However, except as disclosed in this prospectus, we have no present plansarrangements with the placement agent for any further services.

In addition, in the ordinary course of their business activities, the placement agent and its affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) 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 placement agent and its 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 issueclients that they acquire, long and/or short positions in such securities and instruments.

The placement agent acted as the placement agent in connection with several registered offerings in the past three years and it received compensation for each such offering. However, except as disclosed in this prospectus, we have no present arrangements with the placement agent for any shares of preferred stock.further services.

Anti-Takeover Provisions

Some provisions of Delaware law and our Certificate of Incorporation and Bylaws could make the following transactions more difficult: an acquisition of us by means of a tender offer; an acquisition of us by means of a proxy contest or otherwise; or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholdersThe placement agent may otherwise considerbe deemed to be in their best interests or in our best interests, including transactions that provide for paymentan underwriter within the meaning of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our Board of Directors. We believe that the benefitsSection 2(a)(11) of the increased protection of our potential ability to negotiate withSecurities Act, and any commissions received by it and any profit realized on the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

Undesignated Preferred Stock. The ability of our Board of Directors, without action by our stockholders, to issue up to 5,000,000 shares of undesignated preferred stock with voting or other rights or preferences as designated by our Board of Directors could impede the success of any attempt to effect a change in control of our company. These and other provisions may have the effect of deterring hostile takeovers or delaying changes in control or management of our company.

Dual Class Stock. As described above in “— Common Stock — Voting,” our Certificate of Incorporation provides for a dual class common stock structure, consisting of Common Stock and Class B Common Stock (collectively, our “common stock”), which provides holders of our Class B Common Stock with significant influence over matters requiring stockholder approval, including the election of directors and significant corporate transactions, such as a merger or other sale of our company or its assets.

Stockholder Meetings. Our Bylaws provide that a special meeting of stockholders maysecurities offered hereby by it while acting as principal might be called only by the chair of our Board of Directors, our chief executive officer or president (in the absence of a chief executive officer), or by a resolution adopted by a majority of our Board of Directors.

Requirements for Advance Notification of Stockholder Nominations and Proposals. Our Bylaws include advance notice procedures with respect to stockholder proposalsdeemed to be brought before a stockholder meeting and the nomination of candidates for election as directors, other than nominations made byunderwriting discounts or at the direction of our Board of Directors or a committee of our Board of Directors.

Elimination of Stockholder Action by Written Consent. Any action to be taken by our stockholders must be effected at duly called annual or special meetings of stockholders and may not be taken by written consent.

Staggered Board. Our Board of Directors is divided into three classes. The directors in each class serve a three-year term, with one class being elected each year by our stockholders. This system of electing and removing directors may tend to discourage a third party from making a tender offer or otherwise attempting to obtain control of us, because it generally makes it more difficult for stockholders to replace a majority of the directors.

Removal of Directors. Our Certificate of Incorporation provides that no member of our Board of Directors may be removed from office by our stockholders except for cause and, in addition to any other vote required by law, upon the approval of the holders of at least two-thirds in voting power of the outstanding shares of stock entitled to vote in the election of directors.

Stockholders Not Entitled to Cumulative Voting. Our Certificate of Incorporation does not permit stockholders to cumulate their votes in the election of directors. Accordingly, the holders of a majority of the outstanding shares of our common stock entitled to vote in any election of directors are able to elect all of the directors standing for election, if they choose. Further, as discussed above, holders of our Class B Common Stock are entitled to five votes for each share of Class B Common Stock held by them, including with respect to election of directors.

Choice of Forum. Our Certificate of Incorporation provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for (1) any derivative action or proceeding brought on our behalf, (2) any action asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders, (3) any action asserting a claim against us arising pursuant to any provision of the DGCL or as to which the DGCL confers jurisdiction on the Court of Chancery of the State of Delaware, (4) any action to interpret, apply, enforce or determine the validity of our Certificate of Incorporation or Bylaws, or (5) any action asserting a claim governed by the internal affairs doctrine. Under our Certificate of Incorporation, this exclusive forum provision will not apply to claims which are vested in the exclusive jurisdiction of a court or forum other than the Court of Chancery of the State of Delaware, or for which the Court of Chancery of the State of Delaware does not have subject matter jurisdiction. For instance, the provision would not apply to actions arising under federal securities laws, including suits brought to enforce any liability or duty created by the Securities Act, the Exchange Act, or the rules and regulations thereunder.

Our Certificate of Incorporation further provides that the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arisingcommissions under the Securities Act. Our CertificateThe placement agent will be required to comply with the requirements of Incorporation also provides thatthe Securities Act and the Exchange Act, including, without limitation, Rule 10b-5 and Regulation M under the Exchange Act. These rules and regulations may limit the timing of purchases and sales of our securities by the placement agent. Under these rules and regulations, the placement agent may not (i) engage in any stabilization activity in connection with our securities; and (ii) bid for or purchase any of our securities or attempt to induce any person or entity holding, purchasing, or otherwise acquiringto purchase any interest in shares of our capitalsecurities, other than as permitted under the Exchange Act, until they have completed their participation in the distribution.

Listing and Transfer Agent

Our Class A common stock is listed on the Nasdaq Capital Market and trades under the symbol “LGVN.” The transfer agent of our Class A common stock is Colonial Stock Transfer Company, Inc. There is no established public trading market for the Class A common warrants or pre-funded warrants, and we do not plan on making an application to list the Class A common warrants or pre-funded warrants on the Nasdaq Capital Market, any national securities exchange or other nationally recognized trading system. We will act as the registrar and transfer agent for the Class A common warrants.

Electronic Distribution

This prospectus in electronic format may be deemed to have notice ofmade available on websites or through other online services maintained by the placement agent, or by its affiliates. Other than this prospectus in electronic format, the information on the placement agent’s website and to have consented to these choice of forum provisions. It is possible that a court of law could rule that the choice of forum provisionany information contained in our Certificateany other website maintained by the placement agent is not part of Incorporation are inapplicable or unenforceable if they are challenged in a proceeding or otherwise.

Amendment of Charter Provisions. The amendment of any of the above provisions, except for the provision making it possible for our Board of Directors to issue preferred stock and the provision prohibiting cumulative voting, would require approval by holders of at least two-thirds in voting power of the outstanding shares of stock entitled to vote thereon.

The provisions of Delaware law, and our Certificate of Incorporation and Bylaws, could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our Common Stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in the composition of our board and management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

Section 203 of the Delaware General Corporation Law. We are subject to Section 203 of the DGCL, which prohibits persons deemed to be “interested stockholders” from engaging in a “business combination” with a publicly held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is,this prospectus or the transactionregistration statement of which this prospectus forms a part, has not been approved and/or endorsed by us or the placement agent in which the person becameits capacity as an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliatesunderwriter, and associates, owns, or within three years prior to the determinationshould not be relied upon by investors.

or suit by or in the right of us to procure a judgment in our favor by reason of the fact that the Indemnitee is or was, or has agreed to become, a director or officer, or is or was serving, or has agreed to serve, at our request as a director, officer, partner, employee or trustee of, or in a similar capacity with, another corporation, partnership, joint venture, trust or other enterprise, or by reason of any action alleged to have been taken or omitted in such capacity, against all expenses (including attorneys’ fees) and, to the extent permitted by law, amounts paid in settlement actually and reasonably incurred in connection with such action, suit or proceeding, and any appeal therefrom, if the Indemnitee acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, our best interests, except that no indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to us, unless a court determines that, despite such adjudication but in view of all of the circumstances, he or she is entitled to indemnification of such expenses. Notwithstanding the foregoing, to the extent that any Indemnitee has been successful, on the merits or otherwise, he or she will be indemnified by us against all expenses (including attorneys’ fees) actually and reasonably incurred in connection therewith. Expenses must be advanced to an Indemnitee under certain circumstances.

We have entered into indemnification agreements with each of our directors and officers. These indemnification agreements may require us, among other things, to indemnify our directors and officers for some expenses, including attorneys’ fees, judgments, fines and settlement amounts incurred by a director or officer in any action or proceeding arising out of his or her service as one of our directors or officers, or any other company or enterprise to which the person provides services at our request.

We maintain a general liability insurance policy that covers certain liabilities of directors and officers of our corporation arising out of claims based on acts or omissions in their capacities as directors or officers.

In any underwriting agreement we enter into in connection with the sale of Class A common stock being registered hereby, the underwriters will agree to indemnify, under certain conditions, us, our directors, our officers and persons who control us within the meaning of the Securities Act, against certain liabilities.

Item 15.Recent Sales of Unregistered Securities.

Set forth below is information regarding unregistered securities issued by us within the past three years.years (as adjusted for the 2024 Reverse Split and subject to adjustment based on issuances of additional shares as applicable due to the rounding up of fractional shares resulting from the 2024 Reverse Split). Also included is the consideration received by us for such unregistered securities and information relating to the section of the Securities Act, or rule of the SEC,Securities and Exchange Commission, under which exemption from registration was claimed.

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expire on April13, 2029. The unregistered Series B Warrants have an exercise price of $16.50 per share, became exercisable commencing on the effective date of stockholder approval of the issuance of the Series B Warrants and the shares issuable thereunder, and expire on April14, 2025.

•Pursuant to the Engagement Letter between the Company and H.C. Wainwright & Co., LLC (“Wainwright”), on October13, 2023, we issued to Wainwright, or its designees, warrants to purchase 16,970shares of Common, which have substantially the same terms as the October private placement warrants, except that the exercise price is equal to $20.625 and expire on October11, 2028.

•On December22, 2023, in a private placement concurrent with the December registered direct offering, we sold to an institutional accredited investor warrants to purchase up to an aggregate of 135,531shares of our Class A common stock, which have an exercise price of $16.20 per share, became immediately exercisable upon the issuance thereof, and expire on June22, 2029.

•Pursuant to the Engagement Letter between the Company and Wainwright described herein, on December22, 2023, we issued to Wainwright, or its designees, warrants to purchase 9,488shares of Common, which have substantially the same terms as the December 2023 private placement warrants, except that they have an exercise price equal to $21.813 and expire on December20, 2028.

The offer and sale of all securities listed in this item 15 was made to a limited number of accredited investors and qualified institutional buyers in reliance upon exemptions from the registration requirements pursuant to Section 4(a)(2) under the Securities Act and Regulation D promulgated under the Securities Act. Individuals who purchased securities as described above represented their intention to acquire the securities for investment only and not with a view to or for sale in connection with any distribution thereof, and appropriate legends were affixed to the share certificates issued in such transactions.

Item 16.Exhibits and Financial Statement SchedulesSchedules.

(a)Exhibits.