Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

  NAME OF REPORTING PERSONS

  Krishna Vaddi

  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

  (a)  ☐        (b)  ☐

  SEC USE ONLY

  CITIZENSHIP OR PLACE OF ORGANIZATION

  United States

NUMBER OF

SHARES

 BENEFICIALLY 

OWNED BY

EACH

REPORTING

PERSON

WITH

  SOLE VOTING POWER

  3,618,553⁽¹⁾

  SHARED VOTING POWER

  0

  SOLE DISPOSITIVE POWER

  3,618,553⁽¹⁾

  SHARED DISPOSITIVE POWER

  0

  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

  3,618,553⁽¹⁾

  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

  ☐

  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

  9.7%⁽²⁾

  TYPE OF REPORTING PERSON

  IN

Consists of (i) 1,989,871 shares of voting common stock held by the Reporting Person, of which (a) 444,133 shares are unvested as of December 31, 2021, and subject to forfeiture to the Issuer if the Reporting Person ceases to provide service to the Issuer prior to the vesting of the shares and (b) 936,352 shares of voting common stock subject to options that are exercisable within 60 days of December 31, 2021, (ii) 101,477 shares of voting common stock held by Sidus Ventures, LLC, (iii) 423,655 shares of voting common stock held by Dolphin City Trust, (iv) 551,776 shares of voting common stock held by Blue Sky Trust and (v) 551,774 shares of voting common stock held by Brocade Trust. The Reporting Person is the manager of Sidus Ventures, LLC and may be deemed to have beneficial ownership over the securities held by Sidus Ventures, LLC. The Reporting Person is the beneficiary of Dolphin City Trust and may be deemed to have beneficial ownership over the securities held by Dolphin City Trust. The Reporting Person is the investment advisor for each of the Blue Sky Trust and the Brocade Trust, and may be deemed to have beneficial ownership over the securities held by each of the Blue Sky Trust and the Brocade Trust.

The percentage reported in row 11 is calculated in accordance with Rule 13d-3 based on the aggregate number of shares of common stock beneficial owned by the Reporting Person and an aggregate of 36,200,299 shares of common stock entitled to vote outstanding as of December 31, 2021, as reported by the Issuer to the Reporting Person, plus the number of shares of stock options held by the Reporting Person that are exercisable within 60 days of December 31, 2021, which are treated as converted into common stock only for the purpose of computing the percentage ownership of the Reporting Person.

NAME OF ISSUER:

ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES:

NAME OF PERSONS FILING

ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

CITIZENSHIP:

TITLE OF CLASS OF SECURITIES:

CUSIP NUMBER:

IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR 13D-2(B) OR (C), CHECK WHETHER THE PERSON FILING IS A:

☐   Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o);

☐   Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

☐   Insurance company as defined in section 3(a)19) of the Act (15 U.S.C. 78c);

☐   Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

☐   An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

☐   An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

☐   A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);

☐   A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

☐   A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

☐   A non-U.S. institution in accordance with §240.13d–1(b)(1)(ii)(J);

☐   Group, in accordance with §240.13d–1(b)(1)(ii)(K).

OWNERSHIP:

OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS:

OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON:

IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY:

IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:

NOTICE OF DISSOLUTION OF GROUP:

CERTIFICATION: