Golodirsen

CAMBRIDGE, Mass.--( BUSINESS WIRE )--Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today reported financial results for the third quarter 2024. “ I am pleased to report another strong quarter of performance, as we posted $429.8 million in net product revenue for the third quarter, a 39% increase over the same quarter of the prior year. Reflecting our detailed preparation and track record of commercial execution, the launch of ELEVIDYS is proceeding to plan. ELEVIDYS net product revenue was $181.0 million in the quarter, exceeding prior guidance. If one includes royalty revenue generated on Roche’s ex-US sales of ELEVIDYS, total ELEVIDYS performance was $190.5 million for the quarter. Likewise, net product revenue for our three PMOs -- EXONDYS 51, VYONDYS 53, and AMONDYS 45 – performed well, achieving approximately $248.8 million in the quarter and, as anticipated, reflecting a lack of near-term cannibalization from the launch of ELEVIDYS,” said Doug Ingram, president and chief executive officer, Sarepta Therapeutics. “ At the same time, we have made important decisions regarding portfolio prioritization and have made great progress on our pipeline in the quarter. As examples, by mid-2025 we will have submitted a Biologics License Application for one and will be in clinical trials for two others of our Limb-girdle muscular dystrophy programs. Assuming success, these three therapeutic candidates will deliver our next wave of approved therapies as our multi-program platform advances productively.” Third Quarter 2024 and Recent Developments: Sarepta has made the decision to discontinue the SRP-5051 (vesleteplirsen) development program. This decision was informed by information available to date, including the risk-benefit of the program, feedback from the FDA, and the evolving therapeutic landscape for Duchenne. Presented new data from its neuromuscular portfolio at 2024 World Muscle Society Congress (WMS 2024): Among the multiple presentations from Sarepta at WMS 2024 were new safety and efficacy results from several studies in the SRP-9001 clinical development program. These data included: Skeletal muscle MRI data from Study 9001-301 EMBARK where multiple muscles from a subset of patients (n=39) were evaluated using MRI/MRS and MRI T2 signal prior to treatment and at 52 weeks post treatment. Across all measures, patients treated with SRP-9001 showed improvement over the placebo group with less accumulation of fat and fibrosis. The finding correlates with the functional outcomes in Part 1 of EMBARK which showed stabilization or slowing of disease progression in patients treated with SRP-9001 compared to placebo. Cardiac MRI data from EMBARK where an assessment of a subgroup of patients (n=19), found no negative effects on cardiac safety compared to placebo at 52 weeks and no differences in cardiac measures in SRP-9001-treated patients compared to the placebo group at one year. Sarepta plans for future longitudinal cardiac MRI studies to evaluate the long-term protection of cardiac muscle. Five-year functional results from Study SRP-9001-101, the longest-term data to date for a gene therapy in Duchenne. These patients, with an average age of 10 years at the time of the assessment, were stable or showed a slowing of disease progression with an increase in divergence from natural history over time as shown by an external control analysis. Notably this evaluation was conducted at an age when many Duchenne patients are entering the steep decline phase of the disease. The five-year results showed: A 9.8 point (p=0.0127) increase in change from baseline in the North Star Ambulatory Assessment (NSAA) total score to five years. At year five the sustained increase in NSAA total score was statistically significant and clinically meaningful when compared to an external control cohort. An 8.8 second decrease (p=0.0198) in time to rise from floor, change from baseline to five years. The improvement was statistically significant and clinically meaningful when compared to an external control cohort. Patients maintained their 10-meter walk test time throughout the five years. No new safety signals. Results from EMBARK study of delandistrogene moxeparvovec published in Nature Medicine : In early October, efficacy and safety results from Part 1 of the EMBARK study of delandistrogene moxeparvovec-rokl for the treatment of Duchenne muscular dystrophy were published in Nature Medicine . These published results demonstrate a treatment benefit with delandistrogene moxeparvovec that is clinically meaningful and similar regardless of age and a favorable risk-benefit profile. EMBARK, also known as Study SRP-9001-301, is a global, randomized, double-blind, placebo-controlled, Phase 3 clinical study of delandistrogene moxeparvovec in patients with Duchenne muscular dystrophy between the ages of 4 through 7 years. Conference Call The event will be webcast live under the investor relations section of Sarepta's website at https://investorrelations.sarepta.com/events-presentations and following the event a replay will be archived there for one year. Interested parties participating by phone will need to register using this online form . After registering for dial-in details, all phone participants will receive an auto-generated e-mail containing a link to the dial-in number along with a personal PIN number to use to access the event by phone. Q3 2024 Financial Highlights 1 For the Three Months Ended September 30, 2024 2023 QTD Change (in millions, except for per share amounts) $ % Total Revenues $ 467.2 $ 331.8 135.4 41 % Operating income (loss): GAAP $ 22.2 $ (20.8 ) 43.0 NM* Non-GAAP $ 74.9 $ 37.7 37.2 99 % Net income (loss): GAAP $ 33.6 $ (40.9 ) 74.5 NM* Non-GAAP $ 67.0 $ 31.5 35.5 113 % Diluted earnings (loss) per share: GAAP $ 0.34 $ (0.46 ) 0.80 NM* Non-GAAP $ 0.62 $ 0.31 0.31 99 % For the Nine Months Ended September 30, 2024 2023 YTD Change (in millions, except for per share amounts) $ % Total Revenues $ 1,243.6 $ 846.6 397.0 47 % Operating income (loss): GAAP $ 56.4 $ (292.4 ) 348.8 NM* Non-GAAP $ 216.5 $ (123.5 ) 340.0 NM* Net income (loss): GAAP $ 76.2 $ (581.6 ) 657.8 NM* Non-GAAP $ 191.9 $ (146.1 ) 338.0 NM* Diluted earnings (loss) per share: GAAP $ 0.78 $ (6.56 ) 7.34 NM* Non-GAAP $ 1.78 $ (1.65 ) 3.43 NM* *NM: not meaningful [1] For an explanation of our use of non-GAAP financial measures, please refer to the “Use of Non-GAAP Financial Measures” section later in this press release and for a reconciliation of each non-GAAP financial measure to the most comparable GAAP measures, see the tables at the end of this press release. As of September 30, 2024 As of December 31, 2023 (in millions) Cash, cash equivalents, restricted cash and investments $ 1,395.8 $ 1,691.8 Revenues Total revenues increased by $135.4 million for the three months ended September 30, 2024, compared to the same period of 2023. The increase primarily reflects the initial product launch of ELEVIDYS in June 2023 and expanded label in June 2024, partially offset by a $22.5 million decrease in the amortization of the single, combined performance obligation under our collaboration agreement with F. Hoffman-La Roche Ltd. (“Roche”), which was fully amortized as of December 31, 2023. Total revenues increased by $397.0 million for the nine months ended September 30, 2024, compared to the same period of 2023. The increase primarily reflects the initial product launch of ELEVIDYS in June 2023 and expanded label in June 2024, as well as the $48.0 million of collaboration revenue recognized related to an option declined by Roche to acquire the ex-US rights to a certain external, early stage Duchenne-specific program, partially offset by a $66.8 million decrease in the amortization of the single, combined performance obligation under our collaboration agreement with Roche, which was fully amortized as of December 31, 2023. Additionally, included in total revenues for the three and nine months ended September 30, 2024, is $37.4 million and $45.8 million, respectively, of contract manufacturing and other revenues associated with commercial ELEVIDYS supply delivered to Roche and royalty revenue received from Roche, with no similar activity for the same periods of 2023. Cost of sales (excluding amortization of in-licensed rights) Cost of sales (excluding amortization of in-license rights) increased by $54.7 million and $80.6 million for the three and nine months ended September 30, 2024, respectively, compared with the same periods of 2023. The increases in both periods primarily reflect the initial product launch of ELEVIDYS in June 2023 and expanded label in June 2024. For the three and nine months ended September 30, 2024, we recognized $13.7 million and $15.4 million of cost of sales related to products sold to Roche under our collaboration agreement, with no similar activity for the same periods of 2023. Operating expenses and others Research and development expenses increased by $30.2 million for the three months ended September 30, 2024, compared with the same period of 2023. The increase in research and development expense primarily reflects $55.4 million of costs associated with the termination of the development, commercial manufacturing and supply agreement (the “Thermo Agreement”) related to Brammer Bio MA, LLC, an affiliate of Thermo Fisher Scientific, Inc. in August 2024, net of the reimbursable termination costs by Roche, partially offset by a decrease in clinical and manufacturing activity for our PPMO platform and Eteplirsen program. Research and development expenses decreased by $77.3 million for the nine months ended September 30, 2024, compared with the same period of 2023. The decrease in research and development expense primarily reflects capitalization of commercial batches of ELEVIDYS manufactured after its approval in June 2023, partially offset by $55.4 million of costs associated with the termination of the Thermo Agreement, net of the reimbursable termination costs by Roche. Non-GAAP research and development expenses increased by $35.9 million for the three months ended September 30, 2024, compared with the same period of 2023. Non-GAAP research and development expenses decreased by $65.0 million for the nine months ended September 30, 2024, compared with the same period of 2023. Selling, general and administrative expenses increased by $7.3 million and $43.8 million for the three and nine months ended September 30, 2024, compared with the same periods of 2023. The increase in selling, general and administrative expenses for both periods is primarily driven by professional services used to support the continued efforts to commercialize ELEVIDYS and ongoing litigation matters, the timing of charitable contributions, compensation due to changes in headcount, as well as the achievement of performance conditions related to certain Performance Stock Units. Non-GAAP selling, general and administrative expenses increased by $7.4 million and $40.3 million for the three and nine months ended September 30, 2024, respectively, compared with the same periods of 2023. For the three months ended September 30, 2024, other income (loss), net increased by $24.1 million, compared with the same period of 2023, which primarily reflects an impairment of a strategic investment during the three months ended September 30, 2023, with no similar activity in 2024. For the nine months ended September 30, 2024, other income (loss), net increased by $300.6 million compared with the same period of 2023, which primarily reflects a $387.3 million loss on debt extinguishment offset by a $102.0 million gain on the sale of a Priority Review Voucher (“PRV”) during the nine months ended September 30, 2023, with no similar activities in 2024. Income tax expense for the three months ended September 30, 2024 and 2023, was approximately $0.4 million and $7.8 million, respectively. Income tax expense for the nine months ended September 30, 2024 and 2023, was approximately $12.8 million and $21.2 million, respectively. Income tax expense for all periods presented primarily relates to state, federal and foreign income taxes for which available tax losses or credits were not available to offset. Use of Non-GAAP Measures In addition to the GAAP financial measures set forth in this press release, we have included the following non-GAAP measurements: Non-GAAP income (loss) is defined by us as GAAP net income (loss) excluding interest income, net, depreciation and amortization expense, stock-based compensation expense, the estimated income tax impact of each pre-tax non-GAAP adjustment and other items. Non-GAAP earnings (loss) per share is defined by us as non-GAAP net income (loss), as defined previously, divided by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding. The non-GAAP earnings per share is calculated using diluted shares whereas the non-GAAP net loss per share is calculated using basic shares as all other instruments are anti-dilutive. Non-GAAP operating income (loss) is defined by us as GAAP operating income (loss) excluding depreciation and amortization expense, stock-based compensation expense and other items. Non-GAAP research and development expenses are defined by us as GAAP research and development expenses excluding depreciation and amortization expense, stock-based compensation expense and other items. Non-GAAP selling, general and administrative expenses are defined by us as GAAP selling, general and administrative expenses excluding depreciation expense, stock-based compensation expense and other items. The following components are used to adjust our GAAP financial measures into the previously defined non-GAAP measurements: Interest, depreciation and amortization - Interest income, net amounts can vary substantially from period to period due to changes in cash and debt balances and interest rates driven by market conditions outside of our operations. Depreciation expense can vary substantially from period to period as the purchases of property and equipment may vary significantly from period to period and without any direct correlation to our operating performance. Amortization expense primarily associated with patent costs are amortized over a period of several years after acquisition or patent application or renewal. Stock-based compensation expenses - Stock-based compensation expenses represent non-cash charges related to equity awards we have granted. Although these are recurring charges to operations, we believe the measurement of these amounts can vary substantially from period to period and depend significantly on factors that are not a direct consequence of operating performance that is within our control. Therefore, we believe that excluding these charges facilitates comparisons of our operational performance in different periods. Other items - We evaluate other items of expense and income on an individual basis. We take into consideration quantitative and qualitative characteristics of each item, including (a) nature, (b) whether the items relate to our ongoing business operations, and (c) whether we expect the items to continue or occur on a regular basis. These other items include impairment of strategic investments, change in fair value of derivatives, gain from sale of the PRV and loss on debt extinguishment and may include other items that fit the above characteristics in the future. We exclude from our non-GAAP results: The impairment of any strategic investments as it is a non-cash item and is not considered to be a normal operating expense due to the variability of amount and lack of predictability as to the occurrence and/or timing of such impairments. The loss on debt extinguishment, which is considered to be an infrequent and non-cash event as it is associated with a distinct financing decision and is not indicative of the performance of our core operations, which accordingly, would make it difficult to compare our results to peer companies that also provide non-GAAP disclosures. The gain from sale of the PRV obtained as a result of the FDA accelerated approval of ELEVIDYS in June 2023 as it is a non-recurring event. The change in fair value of derivatives related to 1.) regulatory-related contingent payments meeting the definition of a derivative to Myonexus selling shareholders as well as to an academic institution under a separate license agreement and 2.) the derivative asset associated with capped call options for our $570.0 million aggregate principal amount of senior convertible notes due on November 15, 2024, as these are non-cash items and are not considered to be normal operating expenses due to the variability of amounts and lack of predictability as to occurrence and/or timing. Beginning in the fourth quarter of 2023, amortization of in-licensed rights (formerly included within depreciation and amortization expense) and income tax (benefit) expense are no longer excluded from the non-GAAP results. We now include the income tax effect of adjustments, which represents the estimated income tax impact of each pre-tax non-GAAP adjustment based on the applicable effective income tax rate. Non-GAAP financial results for the for the three and nine months ended September 30, 2023 have been updated to reflect this change for comparability. We use these non-GAAP measures as key performance measures for the purpose of evaluating operational performance and cash requirements internally. We also believe these non-GAAP measures increase comparability of period-to-period results and are useful to investors as they provide a similar basis for evaluating our performance as is applied by management. These non-GAAP measures are not intended to be considered in isolation or to replace the presentation of our financial results in accordance with GAAP. Use of the terms non-GAAP research and development expenses, non-GAAP selling, general and administrative expenses, non-GAAP other income and loss adjustments, non-GAAP operating income (loss), non-GAAP net income (loss), and non-GAAP diluted net earnings (loss) per share may differ from similar measures reported by other companies, which may limit comparability, and are not based on any comprehensive set of accounting rules or principles. All relevant non-GAAP measures are reconciled from their respective GAAP measures in the attached table “ Reconciliation of GAAP Financial Measures to Non-GAAP Financial Measures.” About EXONDYS 51 EXONDYS 51 uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to bind to exon 51 of dystrophin pre-mRNA, resulting in exclusion, or “skipping”, of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 51 skipping. Exon skipping is intended to allow for production of an internally truncated dystrophin protein. EXONDYS 51 is indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 51 skipping. This indication is approved under accelerated approval based on an increase in dystrophin in skeletal muscle observed in some patients treated with EXONDYS 51. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials. EXONDYS 51 has met the full statutory standards for safety and effectiveness and as such is not considered investigational or experimental. Important Safety Information About EXONDYS 51 Hypersensitivity reactions, including bronchospasm, chest pain, cough, tachycardia, and urticaria have occurred in patients who were treated with EXONDYS 51. If a hypersensitivity reaction occurs, institute appropriate medical treatment and consider slowing the infusion or interrupting the EXONDYS 51 therapy. Adverse reactions in DMD patients (N=8) treated with EXONDYS 51 30 mg or 50 mg/kg/week by intravenous (IV) infusion with an incidence of at least 25% more than placebo (N=4) (Study 1, 24 weeks) were (EXONDYS 51, placebo): balance disorder (38%, 0%), vomiting (38%, 0%) and contact dermatitis (25%, 0%). The most common adverse reactions were balance disorder and vomiting. Because of the small numbers of patients, these represent crude frequencies that may not reflect the frequencies observed in practice. The 50 mg/kg once weekly dosing regimen of EXONDYS 51 is not recommended. The most common adverse reactions from observational clinical studies (N=163) seen in greater than 10% of patients were headache, cough, rash, and vomiting. Other adverse events may occur. To report SUSPECTED ADVERSE REACTIONS, contact Sarepta Therapeutics, Inc. at 1-888-SAREPTA (1-888-727-3782) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . For further information, please see the full Prescribing Information . About VYONDYS 53 VYONDYS 53 (golodirsen) uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to bind to exon 53 of dystrophin pre-mRNA, resulting in exclusion, or “skipping,” of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 53 skipping. Exon skipping is intended to allow for production of an internally truncated dystrophin protein. VYONDYS 53 is indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. This indication is approved under accelerated approval based on an increase in dystrophin production in skeletal muscle observed in patients treated with VYONDYS 53. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials. VYONDYS 53 has met the full statutory standards for safety and effectiveness and as such is not considered investigational or experimental. Important Safety Information for VYONDYS 53 CONTRAINDICATIONS: VYONDYS 53 is contraindicated in patients with a serious hypersensitivity reaction to golodirsen or to any of the inactive ingredients in VYONDYS 53. Anaphylaxis has occurred in patients receiving VYONDYS 53. WARNINGS AND PRECAUTIONS Hypersensitivity Reactions : Hypersensitivity reactions, including anaphylaxis, rash, pyrexia, pruritus, urticaria, dermatitis, and skin exfoliation have occurred in VYONDYS 53-treated patients, some requiring treatment. If a hypersensitivity reaction occurs, institute appropriate medical treatment and consider slowing the infusion, interrupting, or discontinuing the VYONDYS 53 therapy and monitor until the condition resolves. VYONDYS 53 is contraindicated in patients with a history of a serious hypersensitivity reaction to golodirsen or to any of the inactive ingredients in VYONDYS 53. Kidney Toxicity: Kidney toxicity was observed in animals who received golodirsen. Although kidney toxicity was not observed in the clinical studies with VYONDYS 53, the clinical experience with VYONDYS 53 is limited, and kidney toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. Kidney function should be monitored in patients taking VYONDYS 53. Because of the effect of reduced skeletal muscle mass on creatinine measurements, creatinine may not be a reliable measure of kidney function in DMD patients. Serum cystatin C, urine dipstick, and urine protein- to-creatinine ratio should be measured before starting VYONDYS 53. Consider also measuring glomerular filtration rate using an exogenous filtration marker before starting VYONDYS 53. During treatment, monitor urine dipstick every month, and serum cystatin C and urine protein-to- creatinine ratio every three months. Only urine expected to be free of excreted VYONDYS 53 should be used for monitoring of urine protein. Urine obtained on the day of VYONDYS 53 infusion prior to the infusion, or urine obtained at least 48 hours after the most recent infusion, may be used. Alternatively, use a laboratory test that does not use the reagent pyrogallol red, as this reagent has the potential to cross react with any VYONDYS 53 that is excreted in the urine and thus lead to a false positive result for urine protein. If a persistent increase in serum cystatin C or proteinuria is detected, refer to a pediatric nephrologist for further evaluation. ADVERSE REACTIONS: Adverse reactions observed in at least 20% of treated patients and greater than placebo were (VYONDYS 53, placebo): headache (41%, 10%), pyrexia (41%, 14%), fall (29%, 19%), abdominal pain (27%, 10%), nasopharyngitis (27%, 14%), cough (27%, 19%), vomiting (27%, 19%), and nausea (20%, 10%). Other adverse reactions that occurred at a frequency greater than 5% of VYONDYS 53-treated patients and at a greater frequency than placebo were: administration site pain, back pain, pain, diarrhea, dizziness, ligament sprain, contusion, influenza, oropharyngeal pain, rhinitis, skin abrasion, ear infection, seasonal allergy, tachycardia, catheter site related reaction, constipation, and fracture. Other adverse events may occur. To report SUSPECTED ADVERSE REACTIONS, contact Sarepta Therapeutics, Inc. at 1-888-SAREPTA (1-888-727-3782) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . For further information, please see the full Prescribing Information . About AMONDYS 45 AMONDYS 45 (casimersen) uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to bind to exon 45 of dystrophin pre-mRNA, resulting in exclusion, or “skipping,” of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 45 skipping. Exon skipping is intended to allow for production of an internally truncated dystrophin protein. AMONDYS 45 is indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 45 skipping. This indication is approved under accelerated approval based on an increase in dystrophin production in skeletal muscle observed in patients treated with AMONDYS 45. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials. AMONDYS 45 has met the full statutory standards for safety and effectiveness and as such is not considered investigational or experimental. Important Safety Information for AMONDYS 45 CONTRAINDICATIONS : AMONDYS 45 is contraindicated in patients with a known serious hypersensitivity to casimersen or any of the inactive ingredients in AMONDYS 45. Instances of hypersensitivity including angioedema and anaphylaxis have occurred. WARNINGS AND PRECAUTIONS Hypersensitivity: Hypersensitivity reactions, including angioedema and anaphylaxis, have occurred in patients who were treated with AMONDYS 45. If a hypersensitivity reaction occurs, institute appropriate medical treatment, and consider slowing the infusion, interrupting, or discontinuing the AMONDYS 45 infusion and monitor until the condition resolves. AMONDYS 45 is contraindicated in patients with known serious hypersensitivity to casimersen or to any of the inactive ingredients in AMONDYS 45. Kidney Toxicity : Kidney toxicity was observed in animals who received casimersen. Although kidney toxicity was not observed in the clinical studies with AMONDYS 45, kidney toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. Kidney function should be monitored in patients taking AMONDYS 45. Because of the effect of reduced skeletal muscle mass on creatinine measurements, creatinine may not be a reliable measure of kidney function in DMD patients. Serum cystatin C, urine dipstick, and urine protein-to-creatinine ratio should be measured before starting AMONDYS 45. Consider also measuring glomerular filtration rate using an exogenous filtration marker before starting AMONDYS 45. During treatment, monitor urine dipstick every month, and serum cystatin C and urine protein-to-creatinine ratio (UPCR) every three months. Only urine expected to be free of excreted AMONDYS 45 should be used for monitoring of urine protein. Urine obtained on the day of AMONDYS 45 infusion prior to the infusion, or urine obtained at least 48 hours after the most recent infusion, may be used. Alternatively, use a laboratory test that does not use the reagent pyrogallol red, as this reagent has the potential to cross react with any AMONDYS 45 that is excreted in the urine and thus lead to a false positive result for urine protein. If a persistent increase in serum cystatin C or proteinuria is detected, refer to a pediatric nephrologist for further evaluation. Adverse Reactions: Adverse reactions occurring in at least 20% of patients treated with AMONDYS 45 and at least 5% more frequently than in the placebo group were (AMONDYS 45, placebo): upper respiratory infections (65%, 55%), cough (33%, 26%), pyrexia (33%, 23%), headache (32%, 19%), arthralgia (21%, 10%), and oropharyngeal pain (21%, 7%). Other adverse reactions that occurred in at least 10% of patients treated with AMONDYS 45 and at least 5% more frequently than in the placebo group were: ear pain, nausea, ear infection, post-traumatic pain, and dizziness and light-headedness. Other adverse events may occur. To report SUSPECTED ADVERSE REACTIONS, contact Sarepta Therapeutics, Inc. at 1-888-SAREPTA (1-888-727-3782) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . For further information, please see the full Prescribing Information . About ELEVIDYS (delandistrogene moxeparvovec-rokl) ELEVIDYS (delandistrogene moxeparvovec-rokl) is a single-dose, adeno-associated virus (AAV)-based gene transfer therapy for intravenous infusion designed to address the underlying genetic cause of Duchenne muscular dystrophy – mutations or changes in the DMD gene that result in the lack of dystrophin protein – through the delivery of a transgene that codes for the targeted production of ELEVIDYS micro-dystrophin in skeletal muscle. ELEVIDYS is indicated for the treatment of Duchenne muscular dystrophy (DMD) in individuals at least 4 years of age. For patients who are ambulatory and have a confirmed mutation in the DMD gene For patients who are non-ambulatory and have a confirmed mutation in the DMD gene. The DMD indication in non-ambulatory patients is approved under accelerated approval based on expression of ELEVIDYS micro-dystrophin (noted hereafter as “micro-dystrophin”) in skeletal muscle. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s). IMPORTANT SAFETY INFORMATION CONTRAINDICATION: ELEVIDYS is contraindicated in patients with any deletion in exon 8 and/or exon 9 in the DMD gene. WARNINGS AND PRECAUTIONS: Infusion-related Reactions: Infusion-related reactions, including hypersensitivity reactions and anaphylaxis, have occurred during or up to several hours following ELEVIDYS administration. Closely monitor patients during administration and for at least 3 hours after the end of infusion. If symptoms of infusion-related reactions occur, slow, or stop the infusion and give appropriate treatment. Once symptoms resolve, the infusion may be restarted at a lower rate. ELEVIDYS should be administered in a setting where treatment for infusion-related reactions is immediately available. Discontinue infusion for anaphylaxis. Acute Serious Liver Injury: Acute serious liver injury has been observed with ELEVIDYS, and administration may result in elevations of liver enzymes (such as GGT, GLDH, ALT, AST) or total bilirubin, typically seen within 8 weeks. Patients with preexisting liver impairment, chronic hepatic condition, or acute liver disease (e.g., acute hepatic viral infection) may be at higher risk of acute serious liver injury. Postpone ELEVIDYS administration in patients with acute liver disease until resolved or controlled. Prior to ELEVIDYS administration, perform liver enzyme test and monitor liver function (clinical exam, GGT, and total bilirubin) weekly for the first 3 months following ELEVIDYS infusion. Continue monitoring if clinically indicated, until results are unremarkable (normal clinical exam, GGT, and total bilirubin levels return to near baseline levels). Systemic corticosteroid treatment is recommended for patients before and after ELEVIDYS infusion. Adjust corticosteroid regimen when indicated. If acute serious liver injury is suspected, consultation with a specialist is recommended. Immune-mediated Myositis: In clinical trials, immune-mediated myositis has been observed approximately 1 month following ELEVIDYS infusion in patients with deletion mutations involving exon 8 and/or exon 9 in the DMD gene. Symptoms of severe muscle weakness, including dysphagia, dyspnea, and hypophonia, were observed. Limited data are available for ELEVIDYS treatment in patients with mutations in the DMD gene in exons 1 to 17 and/or exons 59 to 71. Patients with deletions in these regions may be at risk for a severe immune-mediated myositis reaction. Advise patients to contact a physician immediately if they experience any unexplained increased muscle pain, tenderness, or weakness, including dysphagia, dyspnea, or hypophonia, as these may be symptoms of myositis. Consider additional immunomodulatory treatment (immunosuppressants [e.g., calcineurin-inhibitor] in addition to corticosteroids) based on patient’s clinical presentation and medical history if these symptoms occur. Myocarditis : Acute serious myocarditis and troponin-I elevations have been observed following ELEVIDYS infusion in clinical trials. If a patient experiences myocarditis, those with pre-existing left ventricle ejection fraction (LVEF) impairment may be at higher risk of adverse outcomes. Monitor troponin-I before ELEVIDYS infusion and weekly for the first month following infusion and continue monitoring if clinically indicated. More frequent monitoring may be warranted in the presence of cardiac symptoms, such as chest pain or shortness of breath. Advise patients to contact a physician immediately if they experience cardiac symptoms. Preexisting Immunity against AAVrh74: In AAV-vector based gene therapies, preexisting anti-AAV antibodies may impede transgene expression at desired therapeutic levels. Following treatment with ELEVIDYS, all patients developed anti-AAVrh74 antibodies. Perform baseline testing for presence of anti-AAVrh74 total binding antibodies prior to ELEVIDYS administration. ELEVIDYS administration is not recommended in patients with elevated anti-AAVrh74 total binding antibody titers greater than or equal to 1:400. Adverse Reactions: The most common adverse reactions (incidence ≥5%) reported in clinical studies were vomiting, nausea, liver injury, pyrexia, and thrombocytopenia. Report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088. You may also report side effects to Sarepta Therapeutics at 1-888-SAREPTA (1-888-727-3782). For further information, please see the full Prescribing Information . About Sarepta Therapeutics Sarepta is on an urgent mission: engineer precision genetic medicine for rare diseases that devastate lives and cut futures short. We hold leadership positions in Duchenne muscular dystrophy (DMD) and limb-girdle muscular dystrophies (LGMDs), and we currently have more than 40 programs in various stages of development. Our vast pipeline is driven by our multi-platform Precision Genetic Medicine Engine in gene therapy, RNA and gene editing. For more information, please visit www.sarepta.com or follow us on LinkedIn , X (formerly Twitter) , Instagram and Facebook . Forward-Looking Statements In order to provide Sarepta’s investors with an understanding of its current results and future prospects, this press release contains statements that are forward-looking. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “believes,” “anticipates,” “plans,” “expects,” “will,” “may,” “intends,” “prepares,” “looks,” “potential,” “possible” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements relating to our future operations, financial performance and projections, business plans, market opportunities, priorities and research and development programs and technologies; the potential benefits of our technologies and scientific approaches, including the potential benefits of SRP-9003; and expected milestones and plans, including our expectation that by mid-2025 we will have submitted a Biologics License Application for one, and will be in clinical trials for two others, of our Limb-girdle muscular dystrophy programs. These forward-looking statements involve risks and uncertainties, many of which are beyond Sarepta’s control. Actual results could materially differ from those stated or implied by these forward-looking statements as a result of such risks and uncertainties. Known risk factors include the following: success in preclinical and clinical trials, especially if based on a small patient sample, does not ensure that later clinical trials will be successful, and the results of future research may not be consistent with past positive results or may fail to meet regulatory approval requirements for the safety and efficacy of product candidates; we may not be able to comply with all FDA post-approval commitments and requirements with respect to our products in a timely manner or at all; certain programs may never advance in the clinic or may be discontinued for a number of reasons, including regulators imposing a clinical hold and us suspending or terminating clinical research or trials; if the actual number of patients suffering from the diseases we aim to treat is smaller than estimated, our revenue and ability to achieve profitability may be adversely affected; we may not be able to execute on our business plans, including meeting our expected or planned regulatory milestones and timelines, research and clinical development plans, and bringing our product candidates to market, for various reasons, some of which may be outside of our control, including possible limitations of company financial and other resources, manufacturing limitations that may not be anticipated or resolved for in a timely manner, and regulatory, court or agency decisions, such as decisions by the United States Patent and Trademark Office with respect to patents that cover our product candidates; and those risks identified under the heading “Risk Factors” in our most recent Annual Report on Form 10-K for the year ended December 31, 2023, and our most recent Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by the Company which you are encouraged to review. Internet Posting of Information We routinely post information that may be important to investors in the 'Investors' section of our website at www.sarepta.com . We encourage investors and potential investors to consult our website regularly for important information about us. Sarepta Therapeutics, Inc. Condensed Consolidated Statements of Income (Loss) (unaudited, in thousands, except per share amounts) For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Revenues: Products, net $ 429,771 $ 309,322 $ 1,149,803 $ 779,805 Collaboration and other 37,401 22,495 93,764 66,750 Total revenues 467,172 331,817 1,243,567 846,555 Cost and expenses: Cost of sales (excluding amortization of in-licensed rights) 91,691 37,026 186,795 106,167 Research and development 224,483 194,301 604,569 681,870 Selling, general and administrative 128,200 120,893 393,999 350,171 Amortization of in-licensed rights 602 439 1,804 796 Total cost and expenses 444,976 352,659 1,187,167 1,139,004 Operating income (loss) 22,196 (20,842 ) 56,400 (292,449 ) Other income (loss), net: Other income (expense), net 11,810 (12,332 ) 32,631 17,309 Gain from sale of Priority Review Voucher — — — 102,000 Loss on debt extinguishment — — — (387,329 ) Total other income (loss), net 11,810 (12,332 ) 32,631 (268,020 ) Income (loss) before income tax expense 34,006 (33,174 ) 89,031 (560,469 ) Income tax expense 395 7,763 12,841 21,163 Net income (loss) $ 33,611 $ (40,937 ) $ 76,190 $ (581,632 ) Earnings (loss) per share: Basic $ 0.35 $ (0.46 ) $ 0.80 $ (6.56 ) Diluted $ 0.34 $ (0.46 ) $ 0.78 $ (6.56 ) Weighted average number of shares of common stock used in computing earnings (loss) per share: Basic 95,390 88,889 94,669 88,609 Diluted 100,448 88,889 99,572 88,609 Sarepta Therapeutics, Inc. Reconciliation of GAAP Financial Measures to Non-GAAP Financial Measures (unaudited, in thousands, except per share amounts) For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 GAAP net income (loss) $ 33,611 $ (40,937 ) $ 76,190 $ (581,632 ) Interest income, net (13,415 ) (17,593 ) (43,156 ) (46,565 ) Depreciation and amortization expense* 9,204 10,489 25,465 32,229 Stock-based compensation expense 43,450 48,061 134,624 136,688 Change in fair value of derivatives (1,535 ) 2,000 8,565 1,200 Gain from sale of Priority Review Voucher — — — (102,000 ) Loss on debt extinguishment — — — 387,329 Impairment of strategic investments — 27,500 — 27,821 Income tax effect of adjustments** (4,300 ) 1,992 (9,772 ) (1,197 ) Non-GAAP net income (loss)** $ 67,015 $ 31,512 $ 191,916 $ (146,127 ) GAAP net earnings (loss) per share - diluted: $ 0.34 $ (0.46 ) $ 0.78 $ (6.56 ) Add: impact of GAAP to Non-GAAP adjustments $ 0.28 $ 0.77 $ 1.00 $ 4.91 Non-GAAP net earnings (loss) per share - diluted*** $ 0.62 $ 0.31 $ 1.78 $ (1.65 ) Weighted average number of shares of common stock used in computing diluted earnings (loss) per share:**** GAAP 100,448 88,889 99,572 88,609 Non-GAAP 108,548 101,722 107,672 88,609 *Beginning in the fourth quarter of 2023, depreciation and amortization excludes amortization of in-licensed rights. Non-GAAP financial results for the three and nine months ended September 30, 2023, have been updated to reflect this change for comparability. **Beginning in the fourth quarter of 2023, income tax (benefit) expense is no longer excluded from the non-GAAP results. We have replaced this metric with income tax effect of adjustments, which represents the estimated income tax impact of each pre-tax non-GAAP adjustment based on the applicable statutory income tax rate. Refer below for a reconciliation of effective tax rates. Non-GAAP financial results for the three and nine months ended September 30, 2023, have been updated to reflect this change for comparability. ***Non-GAAP earnings per share is calculated using diluted shares whereas non-GAAP net loss per share is calculated using basic shares as all other instruments are anti-dilutive. There was a $0.04 impact to the calculation of non-GAAP net earnings per share as a result of the inclusion of diluted shares for the three months ended September 30, 2023. ****The difference between the weighted average number of shares of common stock used in computing diluted GAAP and non-GAAP earnings per share for the three and nine months ended September 30, 2024, is a result of the exclusion of the potential share settlement of the 2027 Notes from the GAAP earnings per share as the inclusion of such shares was anti-dilutive. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 Total effective tax rate, GAAP 1.2 % (23.4 ) % 14.4 % (3.8 ) % Less: impact of GAAP to Non-GAAP adjustments 6.2 (16.7 ) (3.8 ) (24.4 ) Total effective tax rate, Non-GAAP 7.4 % (40.1 ) % 10.6 % (28.2 ) % Sarepta Therapeutics, Inc. Reconciliation of GAAP Financial Measures to Non-GAAP Financial Measures (unaudited, in thousands) For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 GAAP research and development expenses $ 224,483 $ 194,301 $ 604,569 $ 681,870 Stock-based compensation expense (18,034 ) (22,325 ) (54,113 ) (60,315 ) Depreciation and amortization expense (6,664 ) (8,109 ) (18,692 ) (24,794 ) Non-GAAP research and development expenses $ 199,785 $ 163,867 $ 531,764 $ 596,761 For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 GAAP selling, general and administrative expenses $ 128,200 $ 120,893 $ 393,999 $ 350,171 Stock-based compensation expense (25,416 ) (25,736 ) (80,511 ) (76,373 ) Depreciation expense (2,540 ) (2,380 ) (6,773 ) (7,435 ) Non-GAAP selling, general and administrative expenses $ 100,244 $ 92,777 $ 306,715 $ 266,363 For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 GAAP operating income (loss) $ 22,196 $ (20,842 ) $ 56,400 $ (292,449 ) Stock-based compensation expense 43,450 48,061 134,624 136,688 Depreciation and amortization expense 9,204 10,489 25,465 32,229 Non-GAAP operating income (loss) $ 74,850 $ 37,708 $ 216,489 $ (123,532 ) Sarepta Therapeutics, Inc. Condensed Consolidated Balance Sheets (unaudited, in thousands, except share and per share data) As of September 30, 2024 As of December 31, 2023 Assets Current assets: Cash and cash equivalents $ 197,855 $ 428,430 Short-term investments 1,000,534 1,247,820 Accounts receivable, net 434,524 400,327 Inventory 565,924 322,859 Manufacturing-related deposits and prepaids 321,055 102,181 Other current assets 165,477 77,714 Total current assets 2,685,369 2,579,331 Property and equipment, net 305,788 227,154 Right of use assets 140,898 129,952 Non-current inventory 202,550 191,368 Non-current investments 181,770 — Other non-current assets 83,559 136,771 Total assets $ 3,599,934 $ 3,264,576 Liabilities and Stockholders’ Equity Current liabilities: Accounts payable $ 118,774 $ 164,918 Accrued expenses 344,830 314,997 Deferred revenue, current portion 127,001 50,416 Current portion of long-term debt 91,595 105,483 Other current liabilities 17,289 17,845 Total current liabilities 699,489 653,659 Long-term debt 1,135,965 1,132,515 Lease liabilities, net of current portion 170,009 140,965 Deferred revenue, net of current portion 325,000 437,000 Contingent consideration 47,400 38,100 Other non-current liabilities 1,000 3,000 Total liabilities 2,378,863 2,405,239 Stockholders’ equity: Preferred stock, $0.0001 par value, 3,333,333 shares authorized; none issued and outstanding — — Common stock, $0.0001 par value, 198,000,000 shares authorized; 95,493,005 and 93,731,831 issued and outstanding at September 30, 2024, and December 31, 2023, respectively 10 9 Additional paid-in capital 5,588,839 5,304,623 Accumulated other comprehensive income, net of tax 2,245 918 Accumulated deficit (4,370,023 ) (4,446,213 ) Total stockholders’ equity 1,221,071 859,337 Total liabilities and stockholders’ equity $ 3,599,934 $ 3,264,576 Source: Sarepta Therapeutics, Inc.

摘要：近年来，基因治疗取得了显著进展。已有超过4000个编码蛋白质的基因与6000多种遗传疾病有关；下一代测序技术彻底改变了遗传疾病的诊断。大多数遗传疾病被认为是非常罕见或超罕见的，这里定义为病例少于1:100,000，但12种批准的基因治疗中（不包括RNA治疗），只有一种针对超罕见疾病。本文探讨了三种适合各种罕见遗传疾病的基因补充疗法方法：慢病毒载体修饰的自体CD34+造血干细胞移植、系统性腺相关病毒（AAV）载体向肝脏的传递，以及AAV向脑脊液和大脑的局部传递。结合RNA疗法，我们为这些基因治疗提出了一个潜在的商业模式。 1.背景 低发病率或低患病率的疾病，通常被称为罕见病，对卫生系统和患者都构成了沉重的负担。诊断罕见病很困难，因为医生对罕见病不太熟悉，而且诊断它们有时需要专门的测试或检查。针对这些疾病的药物开发也落后于更常见的疾病。因此，为了解决这个问题，许多国家通过简化审批流程和授予销售独占权来鼓励开发孤儿药。在美国，罕见病被定义为影响少于20,000名患者的疾病。这一类包括许多遗传病和特定癌症亚型，但这些疾病的药物开发仍然困难。然而，近年来基因治疗的快速发展为治疗罕见遗传病提供了新的希望。在由基因突变和由此导致的基因产物缺失引起的疾病中，基因治疗旨在通过修复或补充缺陷基因来治疗这些疾病。尽管人类基因组包含大约20,000个编码蛋白质的基因，其中超过4000个基因的突变已知会导致6000多种遗传病（OMIM条目统计），但下一代测序（NGS）的出现显著提高了这些疾病的诊断，无论它们的罕见程度如何。 尽管取得了这些进展，孤儿药开发的成本仍然高得令人望而却步。因此，针对遗传病的药物开发和批准，特别是那些影响极少数患者或被认为是超罕见的疾病，仍然缺乏。目前，没有“超罕见”疾病的法律定义；这个子类别是由国家卫生和护理卓越研究所非正式引入的，用于针对患病率低于每50,000人1人的疾病的药物。有些疾病非常罕见，全世界受影响的个体少于30人，以至于n-Lorem基金会考虑进行单一受试者试验。在本文中，我们采用一个任意定义的超罕见疾病，即患病率低于每100,000人1人。 2.目前基因治疗的成功 尽管人类基因治疗的最初尝试遇到了并发症和失败，但近年来批准的基因治疗产品数量有所增加。以下是美国和/或欧盟批准的基因治疗列表，包括RNA治疗，改编自并更新自“2023年细胞和基因治疗的现状”（表1和2）。这些列表不包括癌症基因治疗。 2.1.批准的基因治疗 Luxturna，2017年批准用于Leber先天性黑蒙症（LCA），取得了显著的成功，通过视网膜下注射携带正常人类RPE65 cDNA副本的重组腺相关病毒（AAV），恢复了视力，这种恢复通常被描述为奇迹般的逆转失明。AAV依赖于辅助病毒来完成其生命周期，不会引起任何已知的人类疾病，而且AAV很少整合到宿主基因组中。这一突破强调了基因治疗治疗以前无法治疗的疾病的潜力。Luxturna的成功鼓励了基因治疗领域的进步。紧随Luxturna之后，使用AAV9病毒衣壳的Zolgensma在基因治疗方面取得了更大的成功。脊髓性肌萎缩症（SMA）是一种痛苦的退行性疾病，最严重的婴儿无法发展出坐姿能力，其他人则逐渐失去运动和呼吸功能。SMA是一种相对常见的遗传病，发病率约为每10,000人1人，为Zolgensma创造了一个巨大的市场。从2019年到2021年，有三种使用基因（慢病毒载体）修饰的自体CD34+造血干细胞移植的基因治疗被批准：Zynteglo用于β-地中海贫血，Skysona用于肾上腺脑白质营养不良（ALD），Libmeldy用于脑白质营养不良（MLD）。β-地中海贫血和ALD也可以通过异体造血干细胞移植（HSCT）治疗，但当没有合适的供体时，基因治疗提供了一个可行的选择，自体移植比异体移植风险更低。2022年，Upstaza，rAAV2-hAADC，被批准用于治疗芳香族L-氨基酸脱羧酶（AADC）缺乏症，标志着第一个直接针对大脑的基因治疗。同年，Roctavian和Hemgenix分别被批准用于治疗血友病A和B。血友病的基因治疗取得了与Zolgensma相当的成功，这是由血友病的相对高发病率（血友病A影响1/5,617名男性，血友病B影响1/19,283名男性）推动的。考虑到凝血因子输注的昂贵和不便，这一成功尤为重要。2023年，又有四种基因治疗被批准：Vyjuvek用于大疱性表皮松解症；Lyfgenia，使用编码抗镰状血红蛋白HbAT87Q的慢病毒载体，用于镰状细胞贫血症；Casgevy，采用CRISPR-Cas9，第一种基因编辑疗法，针对BCL11A红细胞特异性增强子，也用于镰状细胞贫血症；Elevidys，用于杜氏肌营养不良症（DMD），这是一种影响大约每5,000名男性1人的遗传性肌肉退行性疾病。 2.2.批准的RNA治疗 批准的RNA治疗比基因补充治疗要多（表2）。反义寡核苷酸（ASOs）和小干扰RNA（RNAi）是两种广泛用于沉默基因表达的策略。如Ionis Pharmaceuticals和Sarepta Therapeutics等公司已经开发了几种针对杜氏肌营养不良症、转甲状腺素（TTR）相关遗传性淀粉样变性和脊髓性肌萎缩症（SMA）的反义疗法（表2）。如Alnylam等公司开发了针对TTR相关遗传性淀粉样变性、卟啉症、高草酸尿症等疾病的RNAi疗法（表2）。TTR相关淀粉样变性是由转甲状腺素系统沉积引起的，临床表现包括神经病变、心肌病和眼肌黄斑病变。ASO和RNAi在破坏互补mRNA和抑制TTR合成方面非常有效。自它们开发以来，Tegsedi（反义疗法）、Onpattro（RNAi）、Amvuttra（RNAi）和Wainua（反义疗法）都已获得治疗TTR相关遗传性淀粉样变性的许可。 2.3.临床试验 还有针对新治疗的临床试验。AAV-G6PC的肝脏转导提高了糖原贮积病Ia型的长期治疗效果。包括肝脏基因库治疗在内的不同策略的基因治疗已在糖原贮积病II型（庞贝病）的治疗中进行了测试。正在研究更多关于眼睛的遗传病。使用马传染性贫血病毒驱动的载体（EIAV-ABCA4）对ABCA4相关Stargardt病的患者进行治疗。反义寡核苷酸可以修复由超罕见ABCA4变体引起的异常剪接，在患有早期Stargardt病的儿童中。AAV5-NR2E3可能会减轻由视紫红质和其他基因突变引起的视网膜退化，在视网膜色素变性患者中。此外，单次给药的载有基因编辑器mRNA的脂质纳米粒子可以灭活Pcsk9基因，以治疗遗传性和获得性高胆固醇血症，目前心脏-1研究正在进行中。 2.4.罕见病的强烈药物开发 像DMD这样的罕见病已经被不同的方法所接近。大约80%的DMD突变可能适合外显子跳跃。Eteplirsen（Exondys 51, Sarepta Pharmaceuticals）是FDA在2016年批准的第一种外显子跳跃药物治疗。外显子53跳跃，golordirsen（Vyondys 53, Sarepta Pharmaceuticals），增加了一小部分符合条件DMD患者的比例。读穿药物ataluren（Translarna）针对大约13%的有错义突变的DMD患者。此外，Elevidys，一种基于AAV的基因补充治疗，提供了一份微营养不良蛋白cDNA的副本，可能使所有DMD患者受益。另一个例子是亨廷顿病（HD），它是由亨廷顿基因上的CAG重复病理性扩展引起的。有几种方法可以减少突变亨廷顿蛋白的表达。用针对HD突变相关单核苷酸多态性的ASOs抑制亨廷顿蛋白可以恢复HD小鼠模型的认知功能。通过系统给药使用载脂蛋白A-I纳米盘可以将降低突变亨廷顿蛋白的ASOs输送到大脑。miRNA也可以降低亨廷顿水平，并在HD人化小鼠模型中保持纹状体体积和认知功能。一种口服的、能穿透大脑的小分子通过增强假外显子包含来降低亨廷顿水平。在HD小鼠中过表达固醇调节元件结合蛋白2（SREBP2）激活胆固醇生物合成途径基因的转录，清除突变亨廷顿聚集体，并减轻行为缺陷。 2.5.超罕见遗传病的少数治疗方法 在这些已经批准基因治疗的疾病中，SMA、DMD和血友病A的发病率最高，至少每10,000人中有1人。LCA的发病率范围在1/33,000到80,000之间。AADC缺乏症，只有140例记录在案（Orphanet报告2023年11月），在这种情况下是唯一的超罕见疾病。ALD（1:20,000–50,000）和MLD（1:40,000–100,000）的发病率高于AADC缺乏症；然而，只有一部分患者符合基因治疗的条件，必须在症状出现之前进行。ALD也可以通过异体HSCT治疗，这可能会给Bluebird Bio从这两种产品中获利带来挑战。此外，投入癌症基因治疗的资源比投入遗传病的资源要多得多，特别是嵌合抗原受体（CAR）T细胞治疗。RNA治疗也取得了几次成功，但其高应用潜力在于其生产能力可以扩大到治疗大量患者。因此，开发超罕见遗传病的基因治疗通常在确保资金或资源方面面临困难。 3.超罕见遗传病的负担 鉴于遗传病的数量庞大，许多遗传学家在日常实践中经常遇到各种疾病。一位经验丰富的遗传学家通常能够识别出数百种遗传病。例如，粘多糖贮积症（MPSs）包括I型、II型、III型、IV型、VI型和VII型。黏多糖脂质贮积症（MLs）包括唾液酸苷症、半乳糖苷脂症、MLII和MLIII。糖脂贮积症包括高歇病、尼曼-匹克病A/B、尼曼-匹克病C、GM1和GM2神经节苷脂贮积症和法布里病。糖原贮积症包括糖原贮积病IA、IB、II（庞贝病）和III型。神经递质缺乏包括AADC缺乏症、酪氨酸羟化酶（TH）缺乏症、6-吡喃酮四氢蝶呤合成酶（PTPS）缺乏症和GTP环化水合酶1（GCH1）缺乏症。其他代谢疾病包括尿素循环障碍、氨基酸病和有机酸尿症。骨骼疾病包括埃勒斯-当洛斯综合症（EDS）、脊椎骨骺发育不良（SED）和成骨不全症（OI）。其他类别包括先天性全身性脂肪营养不良、涉及DNA修复缺陷的疾病和各种早婴儿癫痫性脑病（EIEE）的病因。最近，我们描述了34例骨骼疾病的遗传病因，确定了涉及这些疾病的16个基因，平均每种疾病2个患者。在我30年的实践中，我见过这里提到的所有疾病。遗憾的是，很少有特定的治疗方法，其中AADC缺乏症是唯一开发了基因治疗的超罕见疾病。有了足够的资源，这些疾病中的许多都可以用基因治疗来治疗。 4.适合治疗超罕见遗传病的基因治疗方式（图1） 4.1.慢病毒载体修饰的自体CD34+造血干细胞移植（图2） 在前述12种批准的遗传病基因治疗中，有六种利用慢病毒载体修饰的HSCT治疗腺苷脱氨酶缺乏症、β-地中海贫血、MLD、ALD和两种不同的镰状细胞贫血症患者。慢病毒载体，如用于治疗地中海贫血的载体，能够向非分裂细胞传递复杂的组织特异性表达盒，而不促进白血化，与早期临床研究中使用的γ-逆转录病毒载体不同。从理论上讲，任何可以通过传统异体HSCT治疗的遗传病也可以从慢病毒载体修饰的HSCT中受益；此外，基因治疗中的自体移植被认为比异体移植更安全。异体HSCT已被证明对治疗如高歇病和MPSI等疾病有效，尽管由于安全考虑更倾向于酶替代疗法（ERT）。然而，在影响大脑的疾病中，如高歇病III型和MPSIH/S，异体HSCT仍被视为一种治疗选择。人们了解到，移植的造血干细胞可以分化成吞噬细胞，作为小胶质细胞迁移到大脑，然后可以在ALD等疾病中清除异常代谢物，或在溶酶体贮积病中分泌分子以挽救宿主脑细胞。 慢病毒载体修饰的HSCT相对于异体HSCT的优势还包括使用更强的启动子来增加产物表达和密码子优化以增加翻译效率。基因工程可以向基因添加分泌性前导肽，实现类似于ERT的高血水平的转基因产物。慢病毒载体修饰的HSCT可以维持表达蛋白的高和稳定血水平，与ERT中观察到的脉冲式血蛋白水平不同。最近，通过向输注蛋白中添加能够穿透大脑的表位，如转铁蛋白表位或输注蛋白上的受体抗体，开发的针对大脑的ERT已被证明可以促进转铁蛋白受体介导的跨血脑屏障的运输。这种策略可以很容易地适应慢病毒载体修饰的HSCT，通过修改载体中的cDNA序列。 然而，慢病毒载体修饰的HSCT有局限性和并发症。目前，无法调节病毒载体转导后转基因的表达水平。虽然在溶酶体贮积病等条件下，过度表达转基因可能是可以容忍的，因为治疗需要系统地或向脑脊液（CSF）输送大量的酶，但在其他情况下可能是有毒的。例如，在AADC缺乏症的基因治疗中，负责单胺神经递质产生的酶直接输送到壳核，以防止大脑中异位或过度的多巴胺产生。同样，在β-地中海贫血治疗中过度表达β-球蛋白可能导致α-球蛋白的相对缺乏，本质上将疾病转化为α-地中海贫血。因此，用于β-地中海贫血基因治疗的慢病毒载体包含β-球蛋白基因的调节元素。虽然慢病毒载体已被证明比逆转录病毒载体更安全，并且与载体插入相关的白血病无关，但它们最近被怀疑会导致骨髓发育不良（MDS）。鉴于基因治疗的新颖性，在进行治疗前需要仔细评估风险和收益。 图1 超罕见疾病基因治疗的应用。CGD慢性肉芽肿病，EDS埃勒斯-当洛斯综合症，EE癫痫性脑病，ML黏多糖脂质贮积症，MPS粘多糖贮积症，NBIA脑铁积累性神经变性，OA有机酸尿症，OI成骨不全症，SCID严重联合免疫缺陷，SED脊椎骨骺发育不良，神经递质缺乏，UCD尿素循环障碍。 图2 慢病毒载体修饰的自体CD34+造血干细胞移植机制。对造血干细胞的转导可以纠正血液中细胞的功能缺陷，包括T细胞、B细胞和巨噬细胞。转基因可以编码分泌性蛋白，这些蛋白被分泌到系统循环中。如果分泌的蛋白包含一个靶向大脑的表位，它就可以进入大脑。骨髓来源的细胞也可以迁移到大脑并分化为小胶质细胞，这些细胞可以改善大脑缺陷。 4.2.系统性给药AAV载体至肝脏（图3） 在12种批准的遗传病基因治疗中，有两种针对肝脏（血友病A和B）、一种针对神经系统（SMA）、一种针对肌肉（DMD）使用系统性给药AAV载体。Zolgensma的系统性输注用于治疗儿童SMA，但计划在成年患者中将载体输送至脑脊液。Elevidys最近被批准用于DMD治疗，剂量为每公斤体重1.33×1014个载体基因组（vg/kg），仍在评估其效果和潜在副作用。系统性给药AAV至肌肉需要高剂量，更有可能引起并发症，包括肝毒性和微血管病变。相反，由于肝脏保留了超过90%的系统性输注AAV载体，系统性给药至肝脏只需要肌肉靶向所需剂量的十分之一，显著降低了并发症的风险。Valoctocogene roxaparvovec（AAV5-hFVIII-SQ）包含一个由肝脏选择性启动子驱动的凝血因子VIII cDNA。在3期研究中，134名血友病A患者接受了6×1013 vg/kg载体的单次输注。一年后的平均凝血因子VIII活性水平增加了41.9 IU/分升。治疗后4周凝血因子VIII浓缩物使用量和治疗出血的年化率分别下降了98.6%和83.8%。试验中没有死亡。Etranacogene dezaparvovec是一种表达Padua因子IX变体的AAV5载体。在3期研究中，54名血友病B患者接受了2×10^13基因组拷贝/公斤体重的载体。年化出血率从导入期的4.19次下降到治疗后7至18个月的1.51次。 在血友病的情况下，肝脏是关键，因为它产生凝血因子。许多其他遗传病，包括有机酸尿症、尿素循环障碍和氨基酸病等代谢疾病，也由肝脏功能障碍引起。像所有载体介导的基因治疗一样，效果可以通过更强或更合适的启动子、密码子优化、分泌性前导肽和针对器官（如大脑）的表位来增强。系统性给药AAV44.9-Mmut载体已被证明可以预防甲基丙二酸血症小鼠的致死性并降低与疾病相关的代谢物。治疗小鼠的组织生物分布和转基因表达研究表明，AAV44.9在转导肝脏和心脏方面非常有效。庞贝病是一种溶酶体贮积症，导致骨骼肌无力和心肌病。最近的数据揭示了2×1011 vg/kg的AAV2/8-LSPhGAA，包含一个肝脏特异性启动子/增强子和前导序列，转导了所有肝细胞，这导致成年GAA-KO小鼠的庞贝病部分生化纠正。 然而，系统性AAV给药受到预先存在的病毒衣壳抗体的阻碍，排除了一些患者接受治疗。此外，肝细胞的周转可以导致随时间推移转基因表达的减少，就像大多数肝脏导向的基因治疗一样，尽管治疗效果减弱的持续时间仍然不确定。最后，尽管AAV不是整合病毒，但观察到一小部分整合到宿主基因组中，这种病毒整合的长期影响尚未完全了解。 图3 系统性AAV载体给药至肝脏的机制。通过静脉输注后，大部分AAV载体被肝脏吸收。被转导的肝细胞恢复其功能，例如通过进行酶反应。如果转基因编码的是一个分泌性蛋白，该蛋白可以被释放到循环系统中以治疗系统性疾病。如果分泌性蛋白包含一个靶向大脑的表位，它就可以进入大脑。 4.3.局部给药AAV载体至脑脊液和大脑用于神经系统疾病治疗（图4） 靶向仍然是基因治疗中最大的挑战。例如，科学家正在研究开发修改后的AAV载体，这些载体靶向肌肉细胞的同时减少肝脏吸收。重新编程AAV衣壳以介导大脑基因输送也正在进行中。然而，AAV载体可以很容易地直接给药至脑脊液空间（鞘内或脑池内）或大脑实质，以治疗影响大脑、脊髓、眼睛和耳朵的疾病。脑脊液和大脑给药有几个优点。首先，所需的载体量大大少于系统性输注所需的量——比系统性AAV给药至肝脏少一个数量级。这种减少节省了成本并最小化了系统性并发症（如肝损伤）的风险。第二，由于中枢神经系统的免疫特权，预先存在的抗体所带来的挑战对于脑脊液和大脑给药来说不那么重要。第三，由于神经元不分裂，AAV的治疗效果可以持久。第四，直接将载体给药至大脑降低了转基因异位表达的风险。 在12种批准的遗传病基因治疗中，有一种靶向眼睛（LCA），一种靶向壳核（AADC缺乏症）通过局部注射AAV载体。两者都使用AAV2，它对神经元细胞表现出高亲和性和有限的组织分布。这些治疗使用最小量的载体，并以高效和缺乏重大并发症为特点。目前，基因治疗正在推进几种眼睛和耳朵疾病的治疗。此外，各种大脑疾病可以从大脑导向的AAV注射中受益。单胺神经递质缺乏可以通过壳核注射来治疗。脑铁积累性神经变性（NBIA）可以通过注射至壳核或苍白球来治疗。原发性肌张力障碍可以通过靶向丘脑来缓解。将AAV载体输送至脑脊液空间是一种治疗具有更广泛大脑病理学的疾病的方法。在人类中，通过侧脑室的AAV给药主要转导室管膜细胞。通过腰穿的给药既方便又实用，特别是对于脊髓疾病。直接注射至大囊（脑池内注射）可能在大脑和脊髓之间提供平衡的载体分布。这些方法可能对许多大脑疾病或具有大脑表现的系统性疾病有益，包括一些溶酶体贮积症。 大脑输送的主要限制在于载体分布是否足够广泛以涵盖所有受影响的大脑区域。例如，脑脊液输送通常导致壳核中的少量神经元转导，而壳核内注射不影响皮层或小脑中的细胞。此外，由于大多数疾病中的大脑病理学是不可逆的，基因治疗的潜在效果可能受到限制。 图4 AAV载体输送至大脑的机制。AAV载体可以直接给药至大脑实质或注射至脑脊液空间（例如，通过腰穿），然后载体迁移至脊髓和大脑。AAV可以转导大脑中的神经细胞并改善它们的功能障碍。转基因可能被分泌出来，以缓解其他细胞的功能障碍。 4.4.RNA治疗和超罕见疾病的基因编辑 上述三种基因治疗模块主要涉及基因补充，但RNA治疗也正成为超罕见疾病最有希望的治疗方法之一。单链DNA或RNA寡核苷酸与RNA结合阻断基因表达，调节剪接，通过RNase H切割DNA•RNA杂交体，并针对miRNA。双链短干扰RNA（siRNAs）与RNA诱导的沉默复合体（RISC）的蛋白机器结合，RISC将其结合的小RNA导向目标互补RNA并通过mRNA切割、降解和翻译抑制来抑制其表达。通过磷酸硫酯（PS）键和化学修饰对DNA或RNA寡核苷酸进行修饰，大大提高了它们的稳定性、与血清蛋白的结合以及与其互补序列的结合亲和力。 ASOs和RNAi可以降低mRNA水平并抑制突变有毒基因产物的表达，如在HD中观察到的，或针对代谢途径中的上游或下游基因以减轻突变的有害效应，如急性肝性卟啉症。此外，ASOs可以调节mRNA剪接；例如，在治疗DMD时，它们可以剪接出包含错义或无义突变的外显子以恢复蛋白质翻译，产生一个较短但功能性的抗肌萎缩蛋白，从而缓解症状。在更独特的案例中，ASOs干扰剪接抑制剂的结合，如在SMA治疗中，以实现正确的剪接。 尽管RNA治疗药物需要定期给药以治疗遗传病，但寡核苷酸可以像小分子药物一样生产和纯化，提供了低生产成本和可扩展性的相同优势。ASOs的行为相当一致，导致可预测的治疗剂量、给药途径、给药频率和潜在副作用。最近，n-Lorem与Ionis Pharmaceuticals合作，为每位患者发现和开发个性化的ASOs——N-of-1疗法。ASOs和RNAi治疗治疗单基因疾病的可能性最近已经回顾。 基因编辑，主要使用CRISPR/Cas，代表了另一种强大的工具，有效地阻断基因表达。目前，CRISPR/Cas9的第一个批准的临床应用是治疗镰状细胞贫血症。由于担心与双链断裂相关的风险，碱基编辑，一种不诱导双链断裂的CRISPR/Cas9衍生物，是一种更安全的替代品，已经催化了几次临床试验。然而，潜在的脱靶效应需要在超罕见疾病的治疗中谨慎应用碱基编辑。在表3中，我们比较了本文提到的治疗模块，并指出了将它们应用于治疗超罕见疾病的可行性。 5.资金、报销和商业模式 尽管基因治疗有潜力改变这些毁灭性罕见病患者的生活，但患者获取这些新疗法远非易事。开发罕见病治疗的障碍超出了技术问题，包括资金、报销策略和商业模式。虽然大多数目前批准的基因治疗针对罕见病，但它们共同对健康和保险系统产生了重大的财务影响。这促使提出了各种支付方法和政策，以确保患者能够获得基因治疗的好处，例如，通过医疗贷款增加药物的负担能力。超罕见疾病的治疗商业模式也很困难。n-Lorem组织为影响全球不到30人的超罕见疾病提出了一种创新方法，采用非营利模式一次治疗一位患者。 然而，本文讨论的基因治疗方式——慢病毒载体修饰的自体CD34+造血干细胞移植、系统性给药AAV至肝脏、给药AAV至脑脊液和大脑，以及RNA治疗——有潜力治疗多种遗传病。在一个有利于创新的监管环境中，一家公司可以专门从事一种技术用于多种疾病，从而节省开发成本、载体生产、生物分布和毒性测试。通过与渴望为患者提供治疗的患者团体和医学社团合作，可以更经济地设计临床试验。例如，在我们为AADC缺乏症开发Upstaza时，这是第一个也是唯一一个针对超罕见疾病的大脑导向基因治疗，我们通过学术研究资助开发它，然后过渡到商业环境。这些战略方法将使公司在扩大超罕见疾病患者获得治疗的同时保持盈利。 6.结论 本文概述了基因治疗的当前成功，包括自体慢病毒载体修饰的造血干细胞移植治疗血液学和神经系统疾病，以及AAV载体介导的基因治疗治疗眼睛、肝脏和神经系统疾病。这些新技术为成千上万的罕见遗传病患者带来了希望。然而，基因治疗的高风险和成本阻碍了其快速发展，尤其是对于只有少数合格患者的超罕见疾病。在本文中，我们提出了几种适合治疗罕见遗传病的基因治疗技术。例如，在系统性给药AAV载体中，肝脏靶向需要较少的载体，但可以治疗肝脏和系统性疾病。直接将AAV载体输送至神经系统也可以治疗神经递质缺乏、原发性肌张力障碍和NBIA。因此，一家公司可以专门从事一种可以针对多种超罕见疾病的技术，以减轻基因治疗开发的财务负担。我们希望更多的超罕见遗传病患者能够尽快接受基因治疗。 识别微信二维码，添加生物制品圈小编，符合条件者即可加入 生物制品微信群！ 请注明：姓名+研究方向！ 版 权 声 明 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