Prime Medicine, Inc.
For the period ended Sep 30, 2025. Filed Nov 7, 2025.
View on SEC.govAbout this filing
A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.
Sep 30, 2025 · Filed Nov 7, 2025
PRME$4.65+4.5%Stored close · as of Nov 6, 2026
What changed in Management’s Discussion and Analysis?
Read the current filingPrevious report: 10-Q
Period ended 2025-06-30; filed 2025-08-07.
0001628280-25-038619
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsCurrent report: 10-Q
Period ended 2025-09-30; filed 2025-11-07.
0001628280-25-050422
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsThe baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.
Compared 109 previous paragraphs and 113 current paragraphs.
55 unchanged; 41 reworded; 13 added; 8 removed; 5 previous and 4 current paragraphs rearranged.
Tables are not compared: 7 previous and 7 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.
A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.
Added paragraphs (13)
Current report
•$4.0 million increase in license and IP costs, primarily due to the issuance of restricted stock units; and
Current report
•$4.0 million decrease in personnel expenses resulting from the workforce reduction announced in May 2025; and
Current report
Interest income
Current report
Increase in interest income is a result of an increase in interest bearing marketable securities purchased from funds raised in our August 2025 offering.
Current report
Concurrently with the filing of this Quarterly Report on Form 10-Q, we plan to file a new registration statement on Form S-3ASR, including a sales agreement prospectus with respect to the ATM Program, to replace the Prior Registration Statement, which will expire on November 13, 2026, in accordance with applicable SEC regulations. Pursuant to Rule 415(a)(6) under the Securities Act, the offering of securities under the Prior Registration Statement will be deemed terminated as of the effectiveness of the new registration statement.
Current report
•$155.1 million net loss;
Current report
•$153.6 million net loss;
Current report
•$55.0 million change in collaboration receivable — related party;
Current report
•$71.9 million change in deferred revenue from consideration received from BMS in September 2024; and
Current report
Net cash provided by investing activities for the nine months ended September 30, 2024 was driven primarily by $25.0 million of maturities of marketable securities, net of purchases, offset by $5.5 million of purchases of property and equipment.
Current report
•$38.1 million of proceeds from issuance of common stock to BMS in September 2024;
Current report
Emerging Growth Company and Smaller Reporting Company Status
Current report
We are also a “smaller reporting company” meaning that the market value of our stock held by non-affiliates is less than $700 million and our annual revenue was less than $100 million during the most recently completed fiscal year. We may continue to be a smaller reporting company if either (i) the market value of our stock held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year and the market value of our stock held by non-affiliates is less than $700 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.
Removed paragraphs (8)
Previous report
For example, in July 2025, we announced that the Cystic Fibrosis Foundation has agreed to provide us with up to $24 million in additional funding to accelerate the development of Prime Editors designed to permanently correct cystic fibrosis-related lung disease. The Cystic Fibrosis Foundation’s additional investment builds on initial funding received under our therapeutic development agreement with the Cystic Fibrosis Foundation in January 2024, and reflects its interest in Prime Editing as a potentially curative approach for cystic fibrosis. We intend to leverage the technology’s versatility and modularity to address multiple disease-causing mutations, potentially treating the vast majority of people with cystic fibrosis. We will initially focus on a program targeting G542X, one of the most prevalent cystic fibrosis-causing nonsense mutations and one for which there are no available therapies. In addition, we will continue to advance hotspot and PASSIGE-based approaches for other mutations with funding received from the Cystic Fibrosis Foundation under its initial commitment in 2024.
Previous report
•$1.8 million decrease in personnel expenses, driven primarily by a decrease of $1.0 million in stock-based compensation expense and fewer R&D personnel resulting from workforce reduction; and
Previous report
•$1.1 million decrease in clinical expenses due to the deprioritization of our CGD programs and discontinuation of our efforts to independently advance our PM359 program to focus on our liver franchise and programs funded through external partnerships.
Previous report
These were offset by:
Previous report
This is offset by:
Previous report
•$104.5 million net loss;
Previous report
•$101.1 million net loss;
Previous report
Emerging Growth Company Status
Reworded paragraphs (41)
Previous wording
Going forward, we will focus our resources on advancing ourin vivo liver franchise, where we are advancing programs to cure two of the largest genetic liver diseases, Wilson’s Disease and Alpha-1 Antitrypsin Deficiency, or AATD. Both programs are currently in late stages of pre-clinical development and are on track for IND and/or CTA filings in the first half of 2026 for Wilson’s Disease and the middle of 2026 for AATD. We intend to leverage the modularity of our platform to expeditiously and efficiently develop these programs supported by our universal liver lipid nanoparticle along with potential regulatory, clinical and other synergies from our modular technology.
Current wording
We are focused on advancing ourin vivo liver franchise, where we are advancing programs to cure two of the largest genetic liver diseases, Wilson’s Disease and Alpha-1 Antitrypsin Deficiency, or AATD. Both programs are currently in late stages of pre-clinical development and are on track for IND and/or CTA filings in the first half of 2026 for Wilson’s Disease and the middle of 2026 for AATD. We intend to leverage the modularity of our platform to expeditiously and efficiently develop these programs supported by our universal liver lipid nanoparticle along with potential regulatory, clinical and other synergies from our modular technology.
Previous wording
We will also continue ourin vivo Cystic Fibrosis program with support from the Cystic Fibrosis Foundation, and our efforts to develop Prime Edited CAR-T products for hematology, immunology and oncology in partnership with Bristol-Myers Squibb Company. In addition, we will continue to pursue additional business development opportunities to accelerate innovation, ensure the broadest application of Prime Editing, and further bolster our financial resources.
Current wording
We also continue to advance ourin vivo Cystic Fibrosis program with support from the Cystic Fibrosis Foundation, and our efforts to develop Prime Edited CAR-T products for hematology, immunology and oncology in partnership with Bristol-Myers Squibb Company. In addition, we will continue to pursue additional business development opportunities to accelerate innovation, ensure the broadest application of Prime Editing, and further bolster our financial resources.
Previous wording
We recently announced initial data from the first patient dosed in our Phase 1/2 trial in chronic granulomatous disease, or CGD. In this patient dosed, a single dose of PM359, our candidate for the treatment of CGD, led to 58% dihydrorhodamine positivity by Day 15, 66% by Day 30 and 71% by Day 60, exceeding levels of dihydrohomadine positivity believed to be potentially curative. In the second patient dosed in the trial, a single dose of PM359 led to a 70% dihydrorhodamine positivity by day 15 and 80% by day 30. In both patients, we also observed successful manufacturing from a single mobilization, no serious adverse events related to PM359 and rapid neutrophil and platelet engraftment when compared to other commercially available autologous genetic therapy benchmarks. We continue to believe PM359 has the potential to transform the care of p47phox CGD. We are planning to have regulatory interactions based on the current data set.
Current wording
In August 2025, we announced additional data from the first patient dosed and initial data from the second patient dosed in our Phase 1/2 trial in chronic granulomatous disease, or CGD. In the first patient dosed, a single dose of PM359, our candidate for the treatment of CGD, led to 58% dihydrorhodamine positivity by Day 15, 66% by Day 30 and 71% by Day 60, exceeding levels of dihydrohomadine positivity believed to be potentially curative. In the second patient dosed in the trial, a single dose of PM359 led to a 70% dihydrorhodamine positivity by day 15 and 80% by day 30. In both patients, we also observed successful manufacturing from a single mobilization, no serious adverse events related to PM359 and rapid neutrophil and platelet engraftment when compared to other commercially available autologous genetic therapy benchmarks. Based on the data from the two patients, we continue to believe PM359 has the potential to transform the care of p47phox CGD. We are planning to have regulatory interactions based on the current data set.
Previous wording
We expect our research and development expenses to continue to increase substantially for the foreseeable future with our planned research and development activities related to developing any future product candidates, including investments in manufacturing, as we advance any product candidates we may identify and begin to conduct clinical trials, and with our obligations under the BMS Collaboration Agreement.
Current wording
We expect our research and development expenses may continue to increase in the future with our planned research and development activities related to developing any future product candidates, including investments in manufacturing, as we advance any product candidates we may identify and begin to conduct clinical trials, and with our obligations under the BMS Collaboration Agreement.
Previous wording
We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support research and development activities; increased accounting, legal, insurance, and investor and public relations costs as we continue to operate as a public company; and additional intellectual property-related expenses as we file patent applications to protect innovations arising from our research and development activities.
Current wording
We anticipate that our general and administrative expenses will increase in the future if we increase our headcount to support research and development activities; increased accounting, legal, insurance, and investor and public relations costs as we continue to operate as a public company; and additional intellectual property-related expenses as we file patent applications to protect innovations arising from our research and development activities.
Previous wording
The $1.7 million decrease in research and development expense for the three months ended June 30, 2025 as compared to the three months ended June 30, 2024 was primarily driven by:
Current wording
The $3.7 million increase in research and development expense for the three months ended September 30, 2025 as compared to the three months ended September 30, 2024 was primarily driven by:
Previous wording
•$6.1 million increase in facility-related expense primarily due to the expansion and build out of our laboratory space at 60 First Street and 500 Arsenal Street; and
Current wording
•$3.6 million increase in facility-related expense primarily due to the expansion and build out of our laboratory space at 60 First Street and 500 Arsenal Street.
Previous wording
•$3.9 million decrease in research costs due to the deprioritization of our CGD programs as we strategically focus our internal efforts on advancing ourin vivo liver franchise; and
Current wording
•$1.3 million decrease in research and development costs due to the deprioritization of our CGD programs as we strategically focus our internal efforts on advancing ourin vivo liver franchise.
Previous wording
The $0.5 million increase in general and administrative expense for the three months ended June 30, 2025 as compared to the three months ended June 30, 2024 is primarily driven by a $1.1 million increase in professional and consultant fees due to an increase in corporate legal expenses.
Current wording
The $2.9 million decrease in general and administrative expense for the three months ended September 30, 2025 as compared to the three months ended September 30, 2024 is primarily driven by a $3.1 million decrease in personnel expenses resulting from the workforce reduction announced in May 2025, including a decrease of $1.9 million in stock-based compensation expense.
Previous wording
Comparison of the Six Months Ended June 30, 2025 and 2024
Current wording
Comparison of the Nine Months Ended September 30, 2025 and 2024
Previous wording
The $1.1 million increase in research and development expense for the six months ended June 30, 2025 as compared to the six months ended June 30, 2024 was primarily driven by:
Current wording
The $4.7 million increase in research and development expense for the nine months ended September 30, 2025 as compared to the nine months ended September 30, 2024 was primarily driven by:
Previous wording
•$2.5 million increase in facility-related expense primarily due to the expansion and build out of our laboratory space at 60 First Street and 500 Arsenal Street; and
Current wording
•$9.7 million increase in facility-related expense primarily due to the expansion and build out of our laboratory space at 60 First Street and 500 Arsenal Street; and
Previous wording
•$1.6 million increase in license and IP costs as we advance ourin vivo liver franchise and pipeline.
Current wording
•$5.3 million increase in license and IP costs as we advance ourin vivo liver franchise and pipeline.
Previous wording
•$2.0 million decrease in personnel expenses, driven primarily by a decrease of $0.9 million in stock-based compensation expense and fewer R&D personnel resulting from the workforce reduction.
Current wording
•$6.0 million decrease in personnel expenses, driven primarily by fewer R&D personnel resulting from the workforce reduction announced in May 2025; and
Previous wording
•$3.3 million decrease in research costs due to the deprioritization of our CGD programs as we strategically focus our internal efforts on advancing ourin vivo liver franchise;
Current wording
•$5.2 million decrease in research costs due to the deprioritization of our CGD programs as we strategically focus our internal efforts on advancing ourin vivo liver franchise.
Previous wording
•$1.4 million increase in personnel expenses in connection with the reduction in force, primarily consisting of one-time severance payments and other employee termination-related expenses; and
Current wording
The $0.3 million decrease in general and administrative expense for the nine months ended September 30, 2025 as compared to the nine months ended September 30, 2024 is primarily driven by $1.7 million decrease in personnel expenses driven primarily by a decrease of $2.3 million in stock-based compensation expense, offset by one-time severance payments and other employee termination-related expenses in connection with the May 2025 reduction in force.
Previous wording
•$1.3 million increase in professional and consultant fees due an increase in corporate legal expenses.
Current wording
This is further offset by a $2.1 million increase in professional and consultant fees due an increase in corporate legal expenses.
Previous wording
Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we advance the preclinical development of our current research programs, commence the clinical development of any product candidates we may identify, and continue our platform development and early-stage research activities. We have not yet commercialized any products and we do not expect to generate revenue from sales of products for several years, if at all. To date, we have funded our operations primarily with proceeds from sales of preferred stock and from our public offerings and through payments from our collaboration partners. As of June 30, 2025, we had cash, cash equivalents, and investments of $101.8 million, excluding our restricted cash, or $115.4 million, including restricted cash.
Current wording
Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we advance the preclinical development of our current research programs, commence the clinical development of any product candidates we may identify, and continue our platform development and early-stage research activities. We have not yet commercialized any products and we do not expect to generate revenue from sales of products for several years, if at all. To date, we have funded our operations primarily with proceeds from sales of preferred stock and from our public offerings and through payments from our collaboration partners. As of September 30, 2025, we had cash, cash equivalents, and investments of $213.3 million, excluding our restricted cash, or $227.0 million, including restricted cash.
Previous wording
In November 2023, we entered into an Open Market Sale Agreement SM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) under which we may, from time to time, issue and sell shares of our common stock having aggregate sales proceeds of up to $300.0 million, in a series of one or more at-the-market equity offerings (the “ATM Program”). Effective July 30, 2025, we terminated the sales agreement prospectus (the “ATM Prospectus”) filed with the shelf registration statement on Form S-3 (File No. 333-275321) and related to the shares of our common stock issuable pursuant to the Sales Agreement. As a result, we will not make any sales of our common stock pursuant to the Sales Agreement, unless and until a new prospectus, prospectus supplement or a new registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect. As of the date of this Quarterly Report on Form 10-Q, we have not sold any shares of common stock under the 2023 ATM program.
Current wording
In November 2023, we entered into an Open Market Sale Agreement SM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) under which we may, from time to time, issue and sell shares of our common stock having aggregate sales proceeds of up to $300.0 million, in a series of one or more at-the-market equity offerings (the “ATM Program”). Effective July 30, 2025, we terminated the sales agreement prospectus (the “ATM Prospectus”) filed with the shelf registration statement on Form S-3 (File No. 333-275321) and related to the shares of our common stock issuable pursuant to the Sales Agreement (the “Prior Registration Statement”). As a result, we will not make any sales of our common stock pursuant to the Sales Agreement, unless and until a new prospectus, prospectus supplement or a new registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect. As of the date of this Quarterly Report on Form 10-Q, we have not sold any shares of common stock under the ATM program.
Previous wording
In August 2025, we issued and sold 43,700,000 shares of our common stock, including 5,700,000 shares pursuant to the exercise of the underwriters’ option to purchase additional shares, at a price to the public of $3.30 per share. As a result of the offering, we received approximately $138.2 million in net proceeds, after deducting underwriting discounts, commissions and offering costs of approximately $6.0 million.
Current wording
In August 2025, we issued and sold 43,700,000 shares of our common stock, including 5,700,000 shares pursuant to the exercise of the underwriters’ option to purchase additional shares, at a price to the public of $3.30 per share. As a result of the offering, we received approximately $138.4 million in net proceeds, after deducting underwriting discounts, commissions and offering costs of approximately $5.8 million.
Previous wording
Net cash used in operating activities for the six months ended June 30, 2025 was driven primarily by the following uses of cash:
Current wording
Net cash used in operating activities for the nine months ended September 30, 2025 was driven primarily by the following uses of cash:
Previous wording
•$2.1 million change in lease liabilities
Current wording
•$3.7 million change in lease liabilities
Previous wording
•$2.4 million change in deferred revenue — related party;
Current wording
•$3.6 million change in deferred revenue — related party; and
Previous wording
•$1.7 million change in accrued expenses and other current liabilities; and
Current wording
•$2.8 million change in accrued expenses and other current liabilities.
Previous wording
These were offset by $22.8 million of non-cash amounts included in net loss, which primarily consisted of stock-based compensation expense, non-cash lease expense, and depreciation expense.
Current wording
•$36.3 million of non-cash amounts included in net loss, which primarily consisted of stock-based compensation expense, restricted stock issuance expense, non-cash lease expense, depreciation expense, and change in fair value of short-term investment — related party;
Previous wording
•$1.5 million change in accounts payable.
Current wording
•$1.6 million change in accounts payable.
Previous wording
Net cash used in operating activities for the six months ended June 30, 2024 was driven primarily by the following uses of cash:
Current wording
Net cash used in operating activities for the nine months ended September 30, 2024 was driven primarily by the following uses of cash:
Previous wording
•$2.5 million change in prepaid and other current assets.
Current wording
•$9.5 million change in prepaid and other current assets;
Previous wording
•$9.2 million change in accounts payable;
Current wording
•$7.7 million change in accounts payable; and
Previous wording
•$5.7 million change in lease liabilities;
Current wording
•$6.0 million change in lease liabilities.
Previous wording
These were offset by $21.3 million of non-cash amounts included in net loss, which primarily consisted of stock-based compensation expense, non-cash lease expense, depreciation expense, and change in fair value of short-term investment — related party.
Current wording
•$32.3 million of non-cash amounts included in net loss, which primarily consisted of stock-based compensation expense, non-cash lease expense, depreciation and amortization expense, and change in fair value of short-term investment — related party;
Previous wording
•$3.9 million change in accrued expenses and other current liabilities; and
Current wording
•$2.0 million change in accrued expenses and other current liabilities.
Previous wording
Net cash used in investing activities for the six months ended June 30, 2025 was driven primarily by the following:
Current wording
Net cash used in investing activities for the nine months ended September 30, 2025 was driven primarily by the following:
Previous wording
•$41.0 million of purchases of marketable securities, net of maturities; and
Current wording
•$132.9 million of purchases of marketable securities, net of maturities; and
Previous wording
Net cash provided by financing activities for the six months ended June 30, 2024 was driven primarily by the following:
Current wording
Net cash provided by financing activities for the nine months ended September 30, 2025 was driven primarily by the following:
Previous wording
Net cash provided by financing activities for the six months ended June 30, 2025 was driven by $6.0 million of proceeds received under our agreement with Cystic Fibrosis Foundation.
Current wording
Net cash provided by financing activities for the nine months ended September 30, 2024 was driven primarily by the following:
Previous wording
•$132.1 million of proceeds from issuances of common stock in our February 2024 public offering;
Current wording
•$132.1 million of net proceeds from issuances of common stock in our February 2024 public offering;
Previous wording
We believe our existing cash, cash equivalents, and investments, including funds from our August 2025 offering, will be sufficient to fund our operating expenses and capital expenditure requirements into 2027. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. We expect that we will require additional funding to:
Current wording
We believe our existing cash, cash equivalents, and investments will be sufficient to fund our operating expenses and capital expenditure requirements into 2027. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. We expect that we will require additional funding to:
Previous wording
During the six months ended June 30, 2025, except for the minimum lease commitments disclosed in Note 6, Leases, to the unaudited condensed consolidated financial statements in this Quarterly Report on Form 10-Q, there were no significant changes to our contractual obligations and commitments described under Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2024.
Current wording
During the nine months ended September 30, 2025, except for the minimum lease commitments disclosed in Note 6, Leases, to the unaudited condensed consolidated financial statements in this Quarterly Report on Form 10-Q, there were no significant changes to our contractual obligations and commitments described under Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2024.
Previous wording
During the six months ended June 30, 2025, there were no material changes to our critical accounting policies and significant judgements described under Management’s Discussion and Analysis of Critical Accounting Policies and Significant Judgments and Estimates which are included in our Annual Report on Form 10-K for the year ended December 31, 2024.
Current wording
During the nine months ended September 30, 2025, there were no material changes to our critical accounting policies and significant judgments described under Management’s Discussion and Analysis of Critical Accounting Policies and Significant Judgments and Estimates which are included in our Annual Report on Form 10-K for the year ended December 31, 2024.
Showing the first 40 of 41 pairs. Open the source sections for the rest.
Rearranged current paragraphs (4)
Current report — wording carried from elsewhere
•$1.9 million change in prepaid and other current assets; and
Current report — wording carried from elsewhere
•$138.4 million of net proceeds from issuances of common stock in our August 2025 public offering; and
Current report — wording carried from elsewhere
•$12.0 million of proceeds received under our agreement with Cystic Fibrosis Foundation.
Current report — wording carried from elsewhere
“opt out” of such extended transition period or (ii) no longer qualify as an emerging growth company. As a result of this election, our condensed consolidated financial statements may not be comparable to other public companies that comply with new or revised accounting pronouncements as of public company effective dates. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.
Rearranged previous paragraphs (5)
Previous report — wording carried elsewhere
•$1.3 million increase in license and IP costs as we advance ourin vivo liver franchise and pipeline.
Previous report — wording carried elsewhere
The $2.6 million increase in general and administrative expense for the six months ended June 30, 2025 as compared to the six months ended June 30, 2024 is primarily driven by:
Previous report — wording carried elsewhere
•$4.0 million of purchases of property and equipment.
Previous report — wording carried elsewhere
Net cash used in investing activities for the six months ended June 30, 2024 was driven primarily by the following:
Previous report — wording carried elsewhere
•$25.9 million of purchases of marketable securities, net of maturities; and