Cautionary Note on Forward-Looking Statements This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, such as statements regarding o

Long-Term Efficacy and Safety of

TransCon PTH in Adults with Hypoparathyroidism: 52-Week Results From the Open-Label Extension of the Phase 3 PaTHway Trial Presented at ENDO 2023 June 17, 2023 Exhibit 99.1

Cautionary Note on Forward-Looking

Statements This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, such as statements regarding our prospective product candidates; clinical trial results; the

expected timing of future clinical trial results; the scope, progress, results and costs of developing our product candidates or any other future product candidates; timing and likelihood of success; plans and objectives of management for future

operations; and future results of current and anticipated products and product candidates are forward-looking statements. These forward-looking statements are based on our current expectations and beliefs, as well as assumptions concerning future

events. These statements involve known and unknown risks, uncertainties and other factors that could cause our actual results to differ materially from the results discussed in the forward-looking statements. These risks, uncertainties and other

factors are more fully described in our reports filed with or submitted to the Securities and Exchange Commission, including, without limitation, our most recent Annual Report on Form 20-F filed with the SEC on February 16, 2023, particularly in the

sections titled "Risk Factors" and "Operating and Financial Review and Prospects." In light of the significant uncertainties in our forward-looking statements, you should not place undue reliance on these statements or regard

these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified timeframe, or at all. Any forward-looking statement made by us in this presentation speaks only as of the date

of this presentation and represents our estimates and assumptions only as of the date of this presentation. Except as required by law, we assume no obligation to update these statements publicly, whether as a result of new information, future

events, changed circumstances or otherwise after the date of this presentation. This presentation concerns product candidates that are or have been under clinical investigation and which have not yet been approved for marketing by the U.S. Food and

Drug Administration, European Medicines Agency or other foreign regulatory authorities. These product candidates are currently limited by U.S. Federal law to investigational use, and no representations are made as to their safety or effectiveness

for the purposes for which they are being investigated. Ascendis, Ascendis Pharma, the Ascendis Pharma logo, the company logo, and TransCon are trademarks owned by the Ascendis Pharma group. June 2023 Ascendis Pharma A/S.

PTH Therapy for Hypoparathyroidism An

intact PTH axis maintains normal serum calcium and phosphate homeostasis1,2 PTH acts on bone, kidney, and indirectly, intestine1,3 Promotes normal nerve and muscle function4 Conventional therapy for hypoparathyroidism (active vitamin D

[e.g., calcitriol, alfacalcidol], calcium) aims to alleviate hypocalcemic symptoms but fails to restore normal PTH physiology PTH therapy for hypoparathyroidism should provide PTH levels within the physiological range and restore downstream

calcitriol, promoting independence from conventional therapy and normalizing: Serum and urine biochemistries Skeletal health Quality of life PTH, parathyroid hormone 1. Brandi ML, et al. J Clin Endocrinol Metab. 2016;101(6):2273-2283. 2.

Shoback DM, et al. J Clin Endocrinol Metab. 2016;101(6):2300-2312. 3. Bilezikian JP, et al. J Clin Endocrinol Metab. 2016;101(6):2313-2324. 4. Mannstadt M, et al. Nat Rev Dis Primers. 2017; 3:17055. 5. Vetter T, et al. Curr Opin Nephrol and

Hypertens. 2002;11:403-410. 2,5

(palopegteriparatide) Design Renal clearance Receptor TransCon carrier TransCon linker PTH (inactive) Active PTH Linker cleavage under physiologic conditions TransCon PTH is an investigational prodrug, administered once daily, with sustained

release of active PTH designed to provide PTH levels in the physiological range for 24 hours/day TransCon PTH is a prodrug of PTH(1-34) developed as a therapy for adults with hypoparathyroidism PTH, parathyroid hormone; TransCon, transient

conjugation Karpf DB, et al. J Bone Miner Res. 2020;35(8):1430-1440.

TransCon PTH Phase 3 PaTHway Trial

Design (NCT04701203) aIndependence from therapeutic doses of calcium is defined as a standing dose of elemental calcium 600 mg on the day prior to the week 52 visit bIndependence from active vitamin D is defined as a standing dose of active

vitamin D equal to zero on the day prior to the week 52 visit BMD, bone mineral density; CTx, C-terminal telopeptide of type 1 collagen; DXA, dual x-ray absorptiometry; HPES, Hypoparathyroidism Patient Experience Scale; SF-36, 36-Item Short Form

Survey; P1NP, procollagen type 1 N-terminal propeptide; PTH, Parathyroid Hormone 82 adults with hypoparathyroidism receiving conventional therapy (active vitamin D + calcium) Screening 4 weeks Week 182 Multi-Component Efficacy Endpoint

Proportion of participants with: Serum calcium in the normal range (8.3-10.6 mg/dL) and Independence from therapeutic doses of calciuma and Independence from active vitamin Db Secondary Endpoints HPES-Symptom physical and cognitive domain

scores HPES-Impact physical functioning and daily life domain scores SF-36 Physical Functioning subscale score Bone turnover markers (P1NP, CTx) and BMD by DXA Co-administered with conventional therapy TransCon PTH 18 g/day, titrated based on

algorithm Placebo, titrated based on algorithm All Participants Week 52 Safety and Tolerability Endpoints 24-hour urine calcium Incidence of Adverse Events, Serious Adverse Events, and Treatment-Emergent Adverse Events Blinded period to Week 26

Randomization (3:1) TransCon PTH (titrated to optimal dose) Open-Label Extension n=78 completed treatment through Week 52

Participant Disposition ITT,

intention-to-treat; PTH, parathyroid hormone Data on file, Ascendis Pharma Discontinued due to: Withdrew consent (n=1) Breast cancer (n=1) Placebo n=19 Randomized N=84 TransCon PTH n=63 Placebo n=21 Not treated due to: Withdrew consent (n=1) Thyroid

cancer recurrence (n=1) Discontinued due to: Fatal cardiac arrest (n=1) Screened N=106 Screen failures (n=22) Completed Week 52 (n=78) Allocation TransCon PTH n=61 Placebo n=21 Analysis Population (ITT/Safety) TransCon PTH n=60 Completed 26-week

blinded treatment & entered OLE Discontinued due to: Relocation (n=1)

Participants Who Met the

Multi-Component Endpoint Criteria at Week 52 81% of participants treated with TransCon PTH met the multi-component efficacy endpoint and 95% achieved independencec from conventional therapy at Week 52 of the PaTHway trial aPercentages are calculated

based on participants who had data on all criteria bNormal range for albumin-adjusted serum calcium = 8.3-10.6 mg/dL cDefined as a standing dose of active vitamin D equal to zero and elemental calcium 600 mg on the day prior to the week 52

visit Data on file, Ascendis Pharma Total TransCon PTH (N=82) Participants with data on all criteria at Week 52, n 78 Participants meeting the multi-component efficacy endpoint criteria at Week 52, n 63 Proportion, % (95% CI)a 81 (70, 89) Number of

participants meeting each component, n (%): Albumin-adjusted serum calcium within the normal rangeb 67 (86) Independence from active vitamin D 78 (100) Independence from therapeutic doses of calcium 74 (95)

Albumin-Adjusted Serum Calcium Levels

at Week 52 Albumin-Adjusted Serum Calcium (mmol/L) Mean ( SE) aAll participants received TransCon PTH during the open-label period bNormal range 8.3-10.6 mg/dL SE, standard error Data on file, Ascendis Pharma 2 4 6 8 10 12 16 20 38 46 | | | |

| | | | | | Mean albumin-adjusted serum calcium levels were maintained within the normal range with TransCon PTH treatment through Week 52 of the PaTHway Trial Double-blind period Open-label perioda Normal Rangeb Albumin-Adjusted Serum Calcium

(mg/dL) Mean ( SE) Weeks

| | | | | | | | | | | | | | |

Double-blind period Open-label perioda Weeks Independence from Conventional Therapy at Week 52 Active Vitamin D Elemental Calcium Active Vitamin D Dose ( g/day) Mean ( SE) Calcium Dose (mg/day) Mean ( SE) Weeks TransCon PTH enabled

rapid and sustained independenceb from conventional therapy over 52 weeks Independenceb from conventional therapy in the placebo/TransCon PTH group from Week 26 through 52 followed a trend similar to that of the active treatment group from baseline

to Week 26 Double-blind period Open-label perioda Therapeutic dose of calcium (>600 mg/day) aAll participants received TransCon PTH during the open-label period bDefined as a standing dose of active vitamin D equal to zero and elemental calcium

600 mg on the day prior to the week 52 visit SE, standard error Data on file, Ascendis Pharma 2023 0 2 4 6 8 10 12 16 20 26 34 38 42 46 52 | | | | | | | | | | | | | | | 0 2 4 6 8 10 12 16 20 26 34 38 42 46 52

HPES-Symptom Scores Through Week 52

HPES-Symptom Physical Domain Score HPES-Symptom Cognitive Domain Score HPES-Symptom scores showed a sustained improvement in hypoparathyroidism-related physical and cognitive symptoms with TransCon PTH treatment over 52 weeks Double-blind period

Open-label perioda Double-blind period Open-label perioda aAll participants received TransCon PTH during the open-label period HPES, Hypoparathyroidism Patient Experience Scale; SE, standard error Data on file, Ascendis Pharma 2023 0 10 20 26 34 52

| | | | | | 0 10 20 26 34 52 | | | | | | Physical Domain Score Mean ( SE) Cognitive Domain Score Mean ( SE)

HPES-Impact Domain Scores Through

Week 52 HPES-Impact Physical Functioning Domain Score HPES-Impact Daily Life Domain Score HPES-Impact scores showed sustained improvement in the impact of hypoparathyroidism on physical functioning and daily life with TransCon PTH In participants

first treated with placebo, HPES scores from weeks 26 to 52 showed the same rapid improvement seen in those treated with TransCon PTH during the blinded period Double-blind period Open-label perioda Double-blind period Open-label perioda aAll

participants received TransCon PTH during the open-label period HPES, Hypoparathyroidism Patient Experience Scale; SE, standard error Data on file, Ascendis Pharma 2023 0 10 20 26 34 52 | | | | | | 0 10 20 26 34 52 | | | | | | Physical Functioning

Domain Score Mean ( SE) Daily Life Domain Score Mean ( SE)

SF-36 Physical Functioning Subscale

Scores Through Week 52 aThe dashed lines (--) indicate the upper (53) and lower (47) bounds of T scores considered to be in the range of average functioning for the U.S. general population of group level data. Group mean scores lower than 47

indicate impairment. Source: Maruish, M. E. (Ed.). User's manual for the SF-36v2 Health Survey (3rd ed.). bAll participants received TransCon PTH during the open-label period. HRQoL, health-related quality of life; SE, standard error;

SF-36, 36-Item Short Form Survey Data on file, Ascendis Pharma 2023 Mean SF-36 Physical Functioning subscale scores at week 52 remained above baseline, showing sustained improvement in HRQoL with TransCon PTH The improvement in SF-36 Physical

Functioning subscale scores with TransCon PTH in those previously treated with placebo mirrored the increase in scores in the TransCon PTH group during the blinded period Double-blind period Open-label periodb Norm (General Population)a SF-36

Physical Functioning Subscale Scorea (Mean SE) 0 10 20 26 34 52 | | | | | |

Double-blind period Open-label

perioda Bone Turnover Markers Through Week 52 Procollagen Type 1 N-Terminal Propeptide (P1NP) C-Terminal Telopeptide of Type 1 Collagen (CTx) In the TransCon PTH/TransCon PTH group, smaller incremental changes were seen in bone turnover markers

between weeks 26 and 52 than baseline to week 26 In the placebo/TransCon PTH group, trends from week 26 through 52 resembled those observed in the active treatment group from baseline to week 26 Double-blind period Open-label perioda aAll

participants received TransCon PTH during the open-label period SE, standard error Data on file, Ascendis Pharma 2023 0 12 26 38 52 | | | | | | | | | | 0 12 26 38 52 P1NP (ng/mL) Mean ( SE) CTx (ng/L) Mean ( SE)

Bone Mineral Density by DXA in

Participants Treated with TransCon PTH from Baseline Through Week 52 an=59 (Baseline), n=58 (Week 26), n=57 (Week 52) bn=59 (Baseline) Data from participants randomized to TransCon PTH at baseline only (TransCon PTH/TransCon PTH group) BMD, bone

mineral density; DXA, dual X-ray absorptiometry Data on file, Ascendis Pharma 2023 Mean Z-Scores BMD Z-scores trended toward age- and sex-matched norms with 52 weeks of TransCon PTH treatment Baseline (n=60) Week 26 (n=59) Week 52 (n=58) Region

Lumbar Spine L1-L4a 1.5 0.7 0.7 Femoral Neck 0.8 0.3 0.3 Total Hip 0.9 0.5 0.4 Distal 1/3 Radiusb 0.3 0.3 0.3

Bone Mineral Density by DXA in

Participants Treated with TransCon PTH from Baseline Through Week 52 an=59 (Baseline), n=58 (Week 26), n=57 (Week 52) bn=60 (Week 26), n=59 (Week 52) cT-score reference point: young (30-year-old) Caucasian adult Data from participants randomized to

TransCon PTH at baseline only (TransCon PTH/TransCon PTH group) DXA, dual X-ray absorptiometry Data on file, Ascendis Pharma 2023 T-scores remained within the normal rangec with TransCon PTH treatment over 52 weeks Baseline (n=60) Week

26 (n=59) Week 52 (n=58) Region Lumbar Spine L1-L4a 0.9 0.1 0.0 Femoral Neck 0.0 -0.5 -0.6 Total Hip 0.4 -0.1 -0.2 Distal 1/3 Radiusb -0.3 -0.3 -0.4 Mean T-Scores

24-Hour Urine Calcium Excretion

Through Week 52 TransCon PTH/TransCon PTH 24-Hour Urine Calcium (mg/day) Mean ( SE) Placebo/ TransCon PTH ULN ( 250 mg/day) TransCon PTH normalized mean 24-hour urine calcium excretion within 26 weeks, which was maintained

through week 52 Mean 24-hour urine calcium normalized within 26 weeks of treatment initiation in the placebo/TransCon PTH group aParticipants randomized to placebo at baseline initiated TransCon PTH treatment at week 26 SE, standard error; ULN,

upper limit of normal Data on file, Ascendis Pharma 2023 a Placebo participants switched to TransCon PTH at week 26 (open-label extension)

Summary of TEAEs in the PaTHway

Trial Through Week 52 Treatment Emergent Adverse Events (TEAEs), n (%) Total TransCon PTHa (N=80) Any TEAE 72 (90.0) Serious TEAE 8 (10.0) Severityb Grade 1 37 (46.3) Grade 2 27 (33.8) Grade 3 7 (8.8) Grade 4 1 (1.3) Related TEAE 42 (52.5)

Serious related TEAEc 2 (2.5) TEAE related to hyper- or hypocalcemia leading to ER/urgent care visit and/or hospitalization 6 (7.5) TEAE leading to discontinuation of study drugd 1 (1.3) TEAE leading to deathd 1 (1.3) aIncludes TEAEs occurring on or

after the first dose of TransCon PTH: 52 weeks of exposure for the TransCon/TransCon group (n=61) and 26 weeks of exposure for the Placebo/TransCon group (n=19); bParticipants are displayed for the highest severity category only; cHypercalcemia

(n=2); d One participant had a TEAE (fatal cardiac arrest unrelated to study drug) leading to discontinuation of the study drug and death during blinded treatment. Data on file, Ascendis Pharma 2023 Most TEAEs were mild or moderate (grades 1-2)

and none reported during the open-label extension led to discontinuation of the trial or TransCon PTH treatment

Conclusions At Week 52, 81% of

participants treated with TransCon PTH achieved normal serum calcium and independencea from conventional therapy. 95% of participants achieved independencea from conventional therapy TransCon PTH resulted in improvements in symptoms and

health-related quality of life within 26 weeks, demonstrated by clinical and patient-reported outcomes, whether participants were randomized to placebo at baseline or in the active treatment group during the blinded period. TransCon PTH normalized

mean 24-hour urine calcium excretion within 26 weeks, which was maintained through Week 52. TransCon PTH continues to be well tolerated in the open-label extension with no new safety signals identified. In adults with hypoparathyroidism, treatment

with TransCon PTH showed sustained efficacy, safety, and tolerability beyond the 26-week blinded period through Week 52 of the PaTHway Trial aDefined as a standing dose of active vitamin D equal to zero and elemental calcium 600 mg on the day

prior to the week 52 visit

Thank you Company contact: Tim Lee

Senior Director, Investor Relations tle@ascendispharma.com (650) 374-6343