Sionna Therapeutics, Inc.
For the period ended Jun 30, 2025. Filed Aug 11, 2025.
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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.
Jun 30, 2025 · Filed Aug 11, 2025
SION$3.280.0%Stored close · as of Nov 6, 2026
What changed in Management’s Discussion and Analysis?
Read the current filingPrevious report: 10-Q
Period ended 2025-03-31; filed 2025-05-12.
0002036042-25-000016
Item 2. Management's Discussion and Analysis of Financial Condition and Results of OperationsCurrent report: 10-Q
Period ended 2025-06-30; filed 2025-08-11.
0002036042-25-000047
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 125 previous paragraphs and 132 current paragraphs.
89 unchanged; 23 reworded; 10 added; 12 removed; 1 previous and 10 current paragraphs rearranged.
Tables are not compared: 4 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 (10)
Current report
In June 2025, we announced positive topline data from our two randomized, double-blinded, placebo-controlled Phase 1 clinical trials evaluating SION-719 and SION-451, our lead NBD1 stabilizer product candidates, in over 200 healthy volunteers. The trials assessed the safety, tolerability, and pharmacokinetics ("PK") of single and multiple ascending doses of each product candidate, as well as food effect and tablet bioequivalence.
Current report
Both SION-719 and SION-451 were generally well tolerated in these trials, with no serious adverse events, treatment emergent adverse events that led to discontinuation of drug, or dose-limiting toxicities observed. The Phase 1 data also supported the use of a tablet formulation in future trials and indicated that both compounds could be dosed in a fed or fasted state. Both NBD1 stabilizers met exposure thresholds that we believe, based on our preclinical CF human bronchial epithelial ("CFHBE") model, have the potential to provide clinically meaningful benefit if administered as an add-on to SOC or in proprietary dual combinations with complementary modulators.
Current report
Based on the Phase 1 results, we are advancing both NBD1 stabilizers —SION-719 and SION-451— to the next phase of clinical development.
Current report
We plan to progress SION-719 into a Phase 2a proof-of-concept trial in CF patients evaluating the compound as an add-on to SOC, pending completion of a drug-drug interaction study to confirm that SION-719 can be dosed with the SOC according to its label. We are on track to initiate the Phase 2a trial in the second half of 2025. SION-451 will advance to a Phase 1 dual combination trial in healthy volunteers evaluating SION-451 in dual combinations with each of galicaftor (SION-2222) and SION-109, two of our complementary CFTR modulators. The trial will evaluate the safety, tolerability, and PK of varying doses of the dual combinations. Initiation is anticipated in the second half of 2025.
Current report
Strategic In-Licensing & Complementary Modulators
Current report
Sources of Liquidity and Financing History
Current report
Research and development expenses increased by $7.2 million to $15.4 million for the three months ended June 30, 2025, from $8.2 million for the three months ended June 30, 2024. The increase in research and development expenses was primarily due to:
Current report
Comparison of the Six Months Ended June 30, 2025 and 2024
Current report
Research and development expenses increased by $10.6 million to $29.1 million for the six months ended June 30, 2025, from $18.5 million for the six months ended June 30, 2024. The increase in research and development expenses was primarily due to:
Current report
General and administrative expenses increased by $6.5 million to $12.5 million for the six months ended June 30, 2025, from $6.0 million for the six months ended June 30, 2024. The increase in general and administrative expenses was primarily due to:
Removed paragraphs (12)
Previous report
In February 2025, we disclosed interim data from our two randomized, double-blinded, placebo-controlled Phase 1 clinical trials of our highly potent NBD1 stabilizers—SION-719 and SION-451—evaluating the safety, tolerability and pharmacokinetic ("PK") profile of single ascending doses ("SAD") and multiple ascending doses ("MAD") of each product candidate in healthy subjects. As of the interim data cutoff date of January 14, 2025, five SAD cohorts and three MAD cohorts of SION-719 had been completed, with over 60 healthy subjects dosed, and six SAD cohorts and three MAD cohorts of SION-451 had been completed, with over 70 healthy subjects dosed. Both SION-719 and SION-451 were generally well tolerated based on interim Phase 1 clinical data as of the interim data cutoff date. As of the interim data cutoff, at both single and multiple doses, SION-719 and SION-451 exposures were achieved that have the potential, based on our preclinical cystic fibrosis human bronchial epithelial (“CFHBE”) model, to provide clinically meaningful benefit if SION-719 or SION-451 were administered as part of a dual combination or as an add-on to the standard of care. We recently completed dosing in the SAD, MAD and food effect and tablet bioequivalence parts of both Phase 1 trials. Both compounds continued to be generally well tolerated, and their safety profiles remained consistent with prior disclosures. Topline data from the Phase 1 trials are expected in the second quarter of 2025.
Previous report
We intend to evaluate an NBD1 stabilizer in combination with the current standard of care in CF patients in a proof-of-concept trial, which we plan to initiate in the second half of 2025, following completion of a drug-drug interaction trial.
Previous report
We will determine the proprietary dual combination that we believe is optimal to advance into a Phase 2b dose-ranging trial in CF patients. We intend to initiate at least one combination MAD trial in the second half of 2025, assessing the safety, tolerability and PK of a dual combination of an NBD1 stabilizer with galicaftor (SION-2222) and/or SION-109 in healthy volunteers, following completion of combination toxicology studies.
Previous report
Research and Development Expenses
Previous report
General and Administrative Expenses
Previous report
Interest Income
Previous report
Other Income
Previous report
Research and Development Expenses
Previous report
Research and development expenses increased by $3.4 million to $13.7 million for the three months ended March 31, 2025, from $10.2 million for the three months ended March 31, 2024. The increase in research and development expenses was primarily due to:
Previous report
General and Administrative Expenses
Previous report
Interest Income
Reworded paragraphs (23)
Previous wording
We believe our robust pipeline of NBD1 stabilizers and complementary CFTR modu lators provide multiple potential pathways to achieving our goal, either in combination with each other to produce a proprietary combination CF therapy, or an NBD1 stabilizer in combination with the current standard of care for CF. We plan to evaluate multiple NBD1 stabilizer candidates and complementary modulator candidates and select the most promising candidates to advance into later-stage development.
Current wording
We believe our robust pipeline of NBD1 stabilizers and complementary CFTR modu lators provide multiple potential pathways to achieving our goal, either in combination with each other to produce a proprietary combination CF therapy, or an NBD1 stabilizer in combination with the current standard of care ("SOC") for CF.
Previous wording
We are also developing a portfolio of complementary CFTR modulators designed to work synergistically with our NBD1 stabilizers to improve CFTR function, as seen in preclinical models. During 2024, we in-licensed three clinical-stage compounds from AbbVie Global Enterprises Ltd. (“AbbVie”) to expand our portfolio of combination product opportunities, including galicaftor (SION-2222), a complementary modulator which targets CFTR’s transmembrane domain 1 (“TMD1”), and has completed Phase 2 clinical trials. In addition, in December
Current wording
Our portfolio of complementary CFTR modulator candidates are designed to work synergistically with our NBD1 stabilizers to improve CFTR function, as seen in preclinical models. During 2024, we in-licensed three clinical-stage compounds from AbbVie Global Enterprises Ltd. (“AbbVie”) to expand our portfolio of combination product opportunities, including galicaftor (SION-2222), a complementary modulator which targets CFTR’s transmembrane domain 1 (“TMD1”), and has completed Phase 2 clinical trials. In addition, in December 2024, we completed a Phase 1 clinical trial evaluating another complementary modulator, SION-109, which targets CFTR’s intracellular loop 4 (“ICL4”) region.
Previous wording
Due to our significant research, development and manufacturing expenditures, we have accumulated substantial losses and negative cash flows since our inception, including net losses of $16.5 million and $11.8 million for the three months ended March 31, 2025, and 2024, respectively. As of March 31, 2025, we had an accumulated deficit of $197.6 million.
Current wording
Due to our significant research, development and manufacturing expenditures, we have accumulated substantial losses and negative cash flows since our inception, including net losses of $34.6 million and $20.4 million for the six months ended June 30, 2025, and 2024, respectively. As of June 30, 2025, we had an accumulated deficit of $215.6 million.
Previous wording
As of March 31, 2025, we had cash, cash equivalents and marketable securities of $354.7 million. Based upon our current operating plans, we believe that with our existing cash, cash equivalents and marketable securities, will be sufficient to fund our operations into 2028. 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. In addition, we could utilize our available capital resources sooner than we expect. See the sections titled “—Liquidity and Capital Resources” and “Risk Factors—Risks Related to Our Limited Operating History, Financial Condition and Need for Additional Capital” included elsewhere in this Quarterly Report.
Current wording
As of June 30, 2025, we had cash, cash equivalents and marketable securities of $337.3 million. Based upon our current operating plans, we believe that with our existing cash, cash equivalents and marketable securities, will be sufficient to fund our operations into 2028. 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. In addition, we could utilize our available capital resources sooner than we expect. See the sections titled “—Liquidity and Capital Resources” and “Risk Factors—Risks Related to Our Limited Operating History, Financial Condition and Need for Additional Capital” included elsewhere in this Quarterly Report.
Previous wording
•the development of commercial-scale manufacturing and distribution processes for our current any future product candidates;
Current wording
•the development of commercial-scale manufacturing and distribution processes for our current and any future product candidates;
Previous wording
A change in the outcome of any of these variables with respect to the development of any current or future product candidate could mean a significant change in the costs and timing associated with the development of that product candidate. For example, if the FDA or another regulatory authority were to delay a planned start of a clinical trial or require us to conduct clinical trials beyond those that we currently anticipate would be required for the completion of clinical development of a product candidate, or if we experience significant delays in our clinical trials due to slower than expected patient enrollment or other reasons, we could be required to expend significant additional financial resources and time on the completion of clinical development of that product candidate. We do not have control over many of these factors, including certain aspects of clinical development, the regulatory submissions process, potential threats to our intellectual property rights and general political and economic conditions that may negatively impact our business in the future. We may never obtain regulatory approval for any of our product candidates, and, even if we do, drug commercialization takes several years and millions of dollars in development costs.
Current wording
A change in the outcome of any of these variables with respect to the development of any current or future product candidate could mean a significant change in the costs and timing associated with the development of that product candidate. For example, if the U.S. Food and Drug Administration ("FDA") or another regulatory authority were to delay a planned start of a clinical trial or require us to conduct clinical trials beyond those that we currently anticipate would be required for the completion of clinical development of a product candidate, or if we experience significant delays in our clinical trials due to slower than expected patient enrollment or other reasons, we could be required to expend significant additional financial resources and time on the completion of clinical development of that product candidate. We do not have control over many of these factors, including certain aspects of clinical development, the regulatory submissions process, potential threats to our intellectual property rights and general political and economic conditions that may negatively impact our business in the future. We may never obtain regulatory approval for any of our product candidates, and, even if we do, drug commercialization takes several years and millions of dollars in development costs.
Previous wording
(1)NBD1 and combination development program costs include NBD1 stabilizer activities and development of our proprietary combination therapy. Complementary modulator program costs include manufacturing expenses for the modulators.
Current wording
(1)NBD1 and combination development program costs include NBD1 stabilizer activities and development of our proprietary combination therapy. Complementary modulator program costs include manufacturing expenses for the complementary modulators.
Previous wording
•direct research and development expenses increased by $1.9 million primarily due to an increase in clinical programs and combination development activities; and
Current wording
•direct research and development expenses increased by $5.4 million primarily due to an increase in clinical programs and combination development activities; and
Previous wording
•unallocated research and development expenses increased by $1.5 million primarily due to a $1.2 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce to support our clinical pipeline.
Current wording
•unallocated research and development expenses increased by $1.8 million primarily due to a $1.4 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce to support our clinical pipeline.
Previous wording
General and administrative expenses increased by $3.1 million to $6.0 million for the three months ended March 31, 2025, from $2.9 million for the three months ended March 31, 2024. The increase in general and administrative expenses was primarily due to:
Current wording
General and administrative expenses increased by $3.5 million to $6.5 million for the three months ended June 30, 2025, from $3.1 million for the three months ended June 30, 2024. The increase in general and administrative expenses was primarily due to:
Previous wording
•$2.0 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce; and
Current wording
•$2.3 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce; and
Previous wording
Interest income increased by $1.9 million to $3.0 million for the three months ended March 31, 2025, from $1.1 million for the three months ended March 31, 2024, primarily driven by an increased investment in debt securities due to the proceeds received from the initial public offering and the amortization of discounts on our investment activity.
Current wording
Interest income increased by $1.1 million to $3.7 million for the three months ended June 30, 2025, from $2.6 million for the three months ended June 30, 2024, primarily driven by an increased investment in debt securities due to the proceeds received from the initial public offering and the amortization of discounts on our investment activity.
Previous wording
Other income was $0.2 million for both the three months ended March 31, 2025, and 2024, due to sublease income in connection with our subleasing agreement.
Current wording
Other income was $0.2 million for the three months ended June 30, 2025, and 2024, due to sublease income in connection with our subleasing agreement.
Previous wording
As of March 31, 2025, we had $354.7 million in cash, cash equivalents and marketable securities.
Current wording
As of June 30, 2025, we had $337.3 million in cash, cash equivalents and marketable securities.
Previous wording
For the three months ended March 31, 2025, net cash used in operating activities was $16.3 million primarily due to our net loss of $16.5 million and changes in operating assets and liabilities of $1.9 million, partially offset by $2.0 million of net non-cash charges, which includes stock-based compensation, depreciation, non-cash operating lease expense and amortization of discounts on marketable securities.
Current wording
For the six months ended June 30, 2025, net cash used in operating activities was $34.4 million primarily due to our net loss of $34.6 million and changes in operating assets and liabilities of $4.2 million, partially offset by $4.4 million of net non-cash charges, which includes stock-based compensation, depreciation, non-cash operating lease expense and amortization of discounts on marketable securities.
Previous wording
For the three months ended March 31, 2024, net cash used in operating activities was $13.2 million primarily due to our net loss of $11.8 million and changes in operating assets and liabilities of $2.5 million, partially offset by $1.2 million of net non-cash charges, which includes stock-based compensation, depreciation, non-cash operating lease expense and amortization of discounts on marketable securities.
Current wording
For the six months ended June 30, 2024, net cash used in operating activities was $23.3 million primarily due to our net loss of $20.4 million and changes in operating assets and liabilities of $4.6 million, partially offset by $1.7 million of net non-cash charges, which includes stock-based compensation, depreciation, non-cash operating lease expense and amortization of discounts on marketable securities.
Previous wording
Net cash used in investing activities was $141.2 million during the three months ended March 31, 2025, which was primarily driven by purchases of marketable securities of $171.6 million, partially offset by maturities of marketable securities of $30.5 million.
Current wording
Net cash used in investing activities was $164.4 million during the six months ended June 30, 2025, which was primarily driven by purchases of marketable securities of $228.0 million, partially offset by maturities of marketable securities of $63.7 million.
Previous wording
Net cash used in investing activities was $123.9 million during the three months ended March 31, 2024, due to purchases of marketable securities.
Current wording
Net cash used in investing activities was $152.5 million during the six months ended June 30, 2024, due to purchases of marketable securities.
Previous wording
Net cash provided by financing activities was $202.4 million during the three months ended March 31, 2025, as compared to $181.3 million during the three months ended March 31, 2024. During the three months ended March 31, 2025, and 2024, the Company closed its IPO and Series C Financing, respectively.
Current wording
Net cash provided by financing activities was $202.1 million during the six months ended June 30, 2025, as compared to $181.4 million during the six months ended June 30, 2024. During the six months ended June 30, 2025, and 2024, the Company closed its IPO and Series C Financing, respectively.
Previous wording
As of March 31, 2025, we had cash, cash equivalents and marketable securities of $354.7 million. Based upon our current operating plans, we believe that our existing cash, cash equivalents and investments in marketable securities, will be sufficient to fund our operations into 2028. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. Additionally, conducting preclinical studies and clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain. We will need to raise substantial additional capital in the future.
Current wording
As of June 30, 2025, we had cash, cash equivalents and marketable securities of $337.3 million. Based upon our current operating plans, we believe that our existing cash, cash equivalents and investments in marketable securities, will be sufficient to fund our operations into 2028. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. Additionally, conducting preclinical studies and clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain. We will need to raise substantial additional capital in the future.
Previous wording
•the timing and amount of milestones, royalties, or other payments we may be required to make to third parties, including Sanofi, CFF and AbbVie, and the terms and timing of establishing and maintaining any other similar arrangements we may enter in the future;
Current wording
•the timing and amount of milestones, royalties, or other payments we may be required to make to third parties, including Sanofi SA, the Cystic Fibrosis Foundation and AbbVie, and the terms and timing of establishing and maintaining any other similar arrangements we may enter in the future;
Previous wording
During the three months ended March 31, 2025, there were no material 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.
Current wording
During the six months ended June 30, 2025, there were no material changes to our contractual obligations and commitments described under "Management’s Discussion and Analysis of Financial Condition and Results of Operations" in the Annual Report.
Previous wording
During the three months ended March 31, 2025, there were no material changes to our critical accounting estimates described under "Management’s Discussion and Analysis of Financial Condition and Results of Operations" in our Annual Report.
Current wording
During the six months ended June 30, 2025, there were no material changes to our critical accounting estimates described under "Management’s Discussion and Analysis of Financial Condition and Results of Operations" in the Annual Report.
Rearranged current paragraphs (10)
Current report — wording carried from elsewhere
The following table summarizes our results of operations (in thousands):
Current report — wording carried from elsewhere
The following table summarizes our research and development expenses (in thousands):
Current report — wording carried from elsewhere
(1)NBD1 and combination development program costs include NBD1 stabilizer activities and development of our proprietary combination therapy. Complementary modulator program costs include manufacturing expenses for the complementary modulators.
Current report — wording carried from elsewhere
•direct research and development expenses increased by $7.3 million primarily due to an increase in clinical programs and combination development activities; and
Current report — wording carried from elsewhere
•unallocated research and development expenses increased by $3.3 million primarily due to a $2.6 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce to support our clinical pipeline.
Current report — wording carried from elsewhere
The following table summarizes our general and administrative expenses (in thousands):
Current report — wording carried from elsewhere
•$4.3 million increase in personnel-related expenses including stock-based compensation, driven by an increase in the size of our workforce; and
Current report — wording carried from elsewhere
•$2.1 million increase in fees related to the increased use of consultants and professional service organizations.
Current report — wording carried from elsewhere
Interest income increased by $3.0 million to $6.7 million for the six months ended June 30, 2025, from $3.7 million for the six months ended June 30, 2024, primarily driven by an increased investment in debt securities due to the proceeds received from the initial public offering and the amortization of discounts on our investment activity.
Current report — wording carried from elsewhere
Other income was $0.3 million for the six months ended June 30, 2025, and 2024, due to sublease income in connection with our subleasing agreement.
Rearranged previous paragraphs (1)
Previous report — wording carried elsewhere
2024, we completed a Phase 1 clinical trial evaluating another complementary modulator, SION-109, which targets CFTR’s intracellular loop 4 (“ICL4”) region.