UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________ Commission File Number: 001-38582 Allakos Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 45-4798831 (State or ot ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________ Commission File Number: 001-38582 Allakos Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 45-4798831 (State or other j ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________ Commission File Number: 001-38582 Allakos Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 45-4798831 (State or other ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38582 Allakos Inc. (Exact name of Registrant as specified in its Charter) Delaware 45-4798831 (State or other jurisdiction of incorpo ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________ Commission File Number: 001-38582 Allakos Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 45-4798831 (State or ot ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to _________ Commission File Number: 001-38582 | --- | --- | --- | |------------------------------------------------------------------------------------ ...

Clinical Development - AK002 has shown activity in clinical trials, depleting blood eosinophils and improving symptoms in patients with chronic urticaria, indolent systemic mastocytosis, and severe allergic conjunctivitis[77]. - The successful development of product candidates remains highly uncertain, with numerous risks and uncertainties impacting the timeline and costs associated with commercialization[88]. - The company has entered into exclusive and nonexclusive license agreements with third parties, with potential milestone payments of up to $4.0 million related to the development of AK002[98][99]. Financial Performance - The company reported a net loss of $20.0 million for the three months ended March 31, 2019, compared to a net loss of $8.5 million for the same period in 2018, with an accumulated deficit of $124.1 million as of March 31, 2019[80]. - Net loss for the three months ended March 31, 2019, was $19.9 million, compared to a net loss of $8.5 million for the same period in 2018, reflecting a 134% increase in losses[107]. - For the three months ended March 31, 2019, the total research and development expenses were $15.1 million, a significant increase from $6.4 million for the same period in 2018[91]. Cash and Funding - As of March 31, 2019, the company had cash, cash equivalents, and marketable securities totaling $167.2 million, expected to fund operations for at least the next 12 months[81]. - Cash, cash equivalents, and marketable securities totaled $167.2 million as of March 31, 2019, sufficient to fund operations for at least the next 12 months[113]. - The company anticipates requiring additional capital to develop product candidates and fund operations in the foreseeable future[121]. Research and Development Expenses - Research and development expenses include costs for consultants, personnel, and third-party service agreements, with external costs from CROs and CDMOs comprising a significant portion[86][89]. - Research and development expenses increased to $15.1 million for the three months ended March 31, 2019, up from $6.4 million in the same period of 2018, representing a 136% increase[108]. General and Administrative Expenses - General and administrative expenses rose to $5.8 million for the three months ended March 31, 2019, compared to $2.3 million in the same period of 2018, an increase of 139%[109]. - The company anticipates an increase in general and administrative expenses to support ongoing research and development activities and compliance with public company regulations[93]. Cash Flow - Net cash used in operating activities was $13.3 million for the three months ended March 31, 2019, compared to $9.3 million for the same period in 2018, indicating a 43% increase in cash outflow[115]. - Net cash provided by investing activities was $10.1 million for the three months ended March 31, 2019, primarily from $81.0 million in proceeds from maturities of marketable securities[117]. IPO and Capital Raising - The company completed an IPO on July 23, 2018, raising net proceeds of $137.3 million from the sale of 8,203,332 shares at $18.00 per share[82]. - The company completed its IPO on July 23, 2018, raising $137.3 million in net proceeds from the sale of 8,203,332 shares at $18.00 per share[112]. Licensing Agreements - The company has made milestone payments of $0.4 million and may be required to make additional payments of up to $41.0 million under a licensing agreement[100]. - The company is subject to minimum annual commercial license fees of $40,000 per year until royalty payments are received[100].

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38582 | --- | --- | |---------------------------------------------------------------------------------------|------------------------ ...