Apitegromab Positioned to be the Potential Next Transformative Therapy for Patients Suffering with SMA KOL Event and Panel Discussion

Apitegromab Positioned to be the Potential Next Transformative Therapy for Patients Suffering with

SMA KOL Event and Panel DiscussionJune 15, 2021

Disclaimers Various statements in this presentation concerning the future expectations, plans and

prospects of Scholar Rock, Inc. ("Scholar Rock"), including without limitation, Scholar Rock's expectations regarding its strategy, its product candidate selection and development timing, including timing for the initiation of and reporting

results from its clinical trials for its product candidates, its disease indication selection and timing for such selection, the ability of apitegromab (SRK-015) to affect the treatment of patients suffering from Spinal Muscular Atrophy (SMA)

either as a monotherapy or in conjunction with the current standard of care, and the ability of SRK-181 to affect the treatment of cancer patients in a manner consistent with preclinical data constitute forward-looking statements for the

purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. The use of words such as "may," "might," "will," "should," "expect," "plan," "anticipate," "believe," "estimate," "target," "project,"

"intend," "future," "potential," or "continue," and other similar expressions are intended to identify such forward-looking statements. Actual results may differ materially from those indicated by these forward-looking statements as a result

of various important factors, including, without limitation, preclinical and clinical data, including the 12-month top-line results from the Phase 2 trial of apitegromab, are not predictive of, are inconsistent with, or more favorable than,

data generated from future clinical trials of the same product candidate, including the planned Phase 3 trial of apitegromab in SMA, Scholar Rock's ability to provide the financial support, resources and expertise necessary to identify and

develop product candidates on the expected timeline, information provided or decisions made by regulatory authorities differ from the company's expectations, competition from third parties that are developing products for similar uses,

Scholar Rock's ability to identify and develop multiple product candidates on the expected timeline, the impacts of the COVID-19 pandemic, Scholar Rock's ability to obtain, maintain and protect its intellectual property, Scholar Rock's

dependence on third parties for development and manufacture of product candidates including to supply any clinical trials, and Scholar Rock's ability to manage expenses and to obtain additional funding when needed to support its business

activities and establish and maintain strategic business alliances and new business initiatives as well as those risks more fully discussed in the section entitled "Risk Factors" in the Quarterly Report on Form 10-Q for the quarter ended

March 31, 2021, which is on file with the Securities and Exchange Commission, as well as discussions of potential risks, uncertainties, and other important factors in Scholar Rock's subsequent filings with the Securities and Exchange

Commission. Any forward-looking statements represent Scholar Rock's views only as of today and should not be relied upon as representing its views as of any subsequent date. Scholar Rock explicitly disclaims any obligation to update any

Agenda 3 Opening Remarks and Spinal Muscular Atrophy Treatment Landscape Tony

KingsleyPresident & CEO Apitegromab TOPAZ Phase 2 Proof-of-Concept Trial ResultsApitegromab Phase 3 Trial Design Considerations Yung Chyung M.D.CMO Moderated byYung Chyung, M.D. Panel Discussion with TOPAZ Trial

Investigators:Thomas Crawford, M.D. - Johns Hopkins MedicineBasil Darras, M.D. - Boston Children's Hospital & Harvard Medical School Jill Jarecki, Ph.D.CSO of Cure SMA Unmet Medical Needs of Individuals with SMA

Apitegromab Shows Transformative Potential in Patients with Type 2 and 3 SMA Spinal Muscular

Atrophy (SMA) remains a devastating and debilitating disease despite the utilization of SMN upregulatorsMulti-pronged approach may be needed in treating SMA; muscle-directed therapy may further improve motor functionApitegromab showed

transformative potential in patients with Type 2/3 SMA thru the TOPAZ Phase 2 trialExciting potential path forward for apitegromabin a rational, targeted, and efficient Phase 3 trial 4 Apitegromab is an investigational product candidate

that is currently being evaluated in a clinical development program for the treatment of SMA. Apitegromab has not been approved by the U.S. Food and Drug Administration (FDA), the European Commission, or any other health or regulatory

authority. The safety and effectiveness of this molecule have not been established.

5 Spinal Muscular Atrophy Overview Significant, progressive motor functionimpairment; many

lose ambulation Infantile onset; unable to sit upindependently Severe, progressive disabilities and unable to walk independently Type 114% Type 251% Type 335% Global disease with 30,000-35,000affected in U.S. and Europe alone TOPAZ*

12-month results showed transformative potential in non-ambulatory Type 2 and 3 patients Represents ~2/3 of overall patient population Motor neuron impairment and loss due to SMN genetic deficiency, leading to muscle atrophy and

weakness *TOPAZ Phase 2 trial evaluated patients with Type 2 and 3 SMA (did not include Type 1)Lallyet al, OrphanetJournal of Rare Diseases, 2017

6 Potential to Pioneer a New Treatment Era: Opportunity forMuscle-Directed Therapy to Complement SMN

Upregulators Phase 3Trial Design Indication MarketPenetration Non-ambulatory Type 2/32-12 years of agePrimary endpoint: Mean change from baseline in HFMSE at 15 months >11,000* patients treated WW$2+ billion in revenues

(LTM) 1,200*** patients treated WW$1.1 billion in revenues (LTM) 3,000** patients treated WWCHF135 million in revenues (LTM) Type 1, 2, and 3 SMA in pediatricand adult patients Type 1, 2, 3 SMA in patients 2 months of age and

older SMA in patients less than 2 years ofage Non-ambulatory Type 2/32-25 years of agePrimary endpoint: Mean change from baseline in MFM-32 at 12 months Infantile-onset Type 1<6 months of agePrimary endpoints: Ability to sit

independently and event-free survival *As of 1Q21 financial update on 4/22/21; includes patients treated worldwide in post-marketing setting, expanded access program, and clinical trials.**As of 1Q21 financial update on 4/21/21; includes

patients treated worldwide between clinical trials, commercial, and compassionate use program.***As of 1Q21 financial update on 4/27/21; commercially, via managed access programs and in clinical trials HFMSE = Hammersmith Functional Motor

Scale Expanded; MFM-32 = Motor Function Measure - 32 items Patients continue to experience major functional impairments despite utilization of SMN upregulators

Apitegromab: Muscle-Directed Therapy Aimed at Complementing SMN Upregulators 7 Myostatin is a

negative regulatorof skeletal muscle growthApitegromab is a fully human, mAb that specifically binds to proforms of myostatin and inhibits myostatin activation Apitegromab is a muscle-directed approach aimed at improving motor

function Adapted from images courtesy of the SMA Foundation Apitegromab SMN upregulators prevent further degeneration of motor neurons...but do not directly address muscle atrophy Motor neurondegeneration Muscle fiber

Cure SMA Jill Jarecki, PhDCSO June 15, 2021

Cure SMA We fund groundbreaking research and provide families thesupport they need for today.Annual

budget of $15M$85 Million in research funding 36 Chapters in the US9,000 affected individuals in membership database300 newly diagnosed contacts annuallyNewly diagnosed care and info packetsInfo on clinical trial recruitment4,000 families

obtain services annuallyAnnual conference, with 2500 attendees

The Evolving Landscape in SMA The FDA-approval of 3 new therapies has revolutionized and dramatically

changed the natural history of SMAEarly identification and treatment dramatically alter long-termoutcomes, most strikingly presymptomaticallySymptomatic treatment providing improvements through increases,stabilization, and slowingMany unmet

needs remain when addressing the complexities of SMAUnmet need is higher in older patients compared to younger patients.

45% of SMA Patients Remain Untreated at End of Q1 2021 Percent of SMA

Patients 70%60%50%40%30%20%10%0%17Q1 Q2 Q3 Q4 18Q1 Q2 Q3 Q4 19Q1 Q2 Q3 Q4 20Q1 Q2 Q3 Q4 21Q1Year QuarterActuals through the end of Q1 2021, with projections for the three quarters after.

Almost Half of Those with SMA Type I Currently Sit without Support

12.90 % 21.90 % 35.37 % 37.66 % 44.64 % 87.10% 78.08% 64.63% 62.30% 55.36% 100%90%80%70%60%50%40%30%20%10%0% 2017 (n=93) 2019 (n=147) 2020 (n=231) 2021 (n=56) 2018 (n=146)Sit without Support Cannot sit without

Can Stand With or Without Support Currently among SMA Type

II 10.94% 11.44% 17.05% 18.36% 89.06% 88.56% 82.95% 81.64% 100%90%80%70%60%50%40%30%20%10%0% 2017(n=265) 2018(n=271) 2019(n=258) 2020(n=414) Can stand (with or without) support Cannot stand (with or without)

support2017 & 2018: Question was what is your maximum current motor function. Assumed able to stand with or without support if any of the following choices were picked: walk alone, walk with assist, cruise along furniture, stand without

support, or stand with support;2019 & 2020: Respondents were asked to answer yes or no if affected child could currently can stand with assistance or stand alone.

What Comes Next - SMA is Not Cured Yet Need More Impact for older ages and stage of SMADifferent for

symptomatic vs NBS patientsSlow to Stop to Reverse Reverse - Restore Function -FutureStop Progression - Prevent SymptomsSlower Progression -ImprovementNatural History - Untreated

Unmet Needs that Future Therapies will Address - From Adults in the 2020 Community Update

Survey 75% 75% 81%80% 71% 29% 89% 89% 81%82%80% 39% 31% 94%94%98% 90% 15% 94% 94% 94% 100%90%80%70%60%50%40%30%20%10%0% Reducing Fatigue Improving breathing function Improving swallowing Gaining muscle

strength Achieving new motor function Improving Improving communication activities of daily through speech living and/or technology Type I Type II Type III

NeuroprotectionNeural transmissionRegenerative targetsMuscle enhancementApitegromab - Scholar

RockGenetic modifiersCombinations of above with SMNenhancer Therapeutic Strategies - SMN Independent

Cure SMA Jill Jarecki, PhDCSO June 15, 2021

Apitegromab Showed Transformative Potential in SMA Phase 2 Trial Yung Chyung, M.D.Chief Medical

TOPAZ: Evolving Understanding of Apitegromab'sTransformative Potential in Type 2 and Type 3

SMA June 2021Additional Analyses April 202112-month top-line October 20206-month interim Showed Initial Proof-of-Concept Interim data showed the therapeutic potential of apitegromab in Type 2 and 3 SMA as add-on therapy to

background nusinersenHFMSE increases in patients who had already received on average ~2 years of background nusinersen therapyMeaningful HFMSE gains over 6-month time frame Further Support for Efficacy Signal Largest HFMSE increases in

non-ambulatory Type 2 and 3 patients; represents ~2/3 of SMA prevalenceDurability of effect with continued improvement in a subset of patientsSupports advancing to a Phase 3 trialAnticipated focus on patients with non- ambulatory Type 2 and

3 2021 Additional exploratory analyses to be presented at future medical congresses Further Support TherapeuticPotential and Phase 3 Plans Additional insights from exploratory analyses offer deeper understanding of

apitegromab's potential profile:Age of patientsDuration of prior background therapySecondary efficacy endpoint (WHO Motor Milestones) 20

21 TOPAZ Top-Line Data Showed Apitegromab'sTransformative Potential in Patients with Type 2/3 SMA

Apitegromab treatment (as add-on to background nusinersen) led to improvements inHFMSE in both non-ambulatory cohorts * Pooled cohorts of non-ambulatory patients treated with apitegromab 20 mg/kg and 2 mg/kg**Non-ambulatory patients who

initiated background nusinersen at a young age of <5 years and treated with apitegromab 20 mg/kg dose At 12 months Mean HFMSE increase 1-point increase 3-point increase Initiated background nusinersen age <5** +7.1 points 88%

(7/8) of patients 63% (5/8) of patients Initiated background nusinersen age 5 +0.6 points 64% (9/14) of patients 29% (4/14) of patients Majority of non-ambulatory patients observed a clinical improvement in

HFMSE* 20151050-5-10 HFMSE change from baseline

Evaluating range of exploratory analyses to better understand the therapeutic responseInitial

findings from non-ambulatory cohorts:HFMSE improvements observed across age range with relatively larger gains from earlier treatmentDuration of prior nusinersen treatment not correlated with HFMSE increaseProvides further support that

improvements may be attributable to apitegromabPatients were already in chronic maintenance phase of nusinersen at enrollmentAchievement by some patients of WHO motor milestones (additional high bar efficacy endpoint) further shows

apitegromab's potentialTotal of 7 patients gained new WHO motor milestones across both non-ambulatory cohorts1 patient* gained 3 milestones (hands & knees crawling, standing with assistance, walking with assistance)1 patient** gained 2

new milestones (hands & knees crawling, standing with assistance)Phase 3 trial in patients with non-ambulatory Type 2 and 3 anticipated to initiate by end of 2021*initiated nusinersen age <5, apitegromab 20 mg/kg 22**initiated

nusinersen age 5 Additional TOPAZ Analyses Further SupportApitegromab's Potential to Improve Motor Function

23 Expectations for Patients on BackgroundSMN Upregulator Therapy Yung Chyung, M.D. Chief Medical

Patients with Type 2 and 3 SMA Continue to Experience MajorFunctional Deficits Despite Improvement

from Nusinersen 24 Darras, B., et.al. Nusinersen in later-onset spinal muscular atrophy. Neurology. May 2019; 92 (21) e2492-e2506.This third-party information is provided for background only and is not intended to convey or imply a

comparison to the TOPAZ clinical trial results. 3.9-point increase in HFMSE from nusinersen 0Mean improvement in HFMSE experienced by patients withnon-ambulatory Type 2/3 SMA in nusinersen Phase 3 CHERISH trial 20 40 HFMSE Score

at Month 15 80Total Possible HFMSE Scoreof 6660 SMN upregulator treated patients continue to experience major functional deficits

Mercuri E, et.al. Nusinersen versus sham control in later-onset spinal muscular atrophy. N Engl J

Med. 2018;378:625-635.This third-party information is provided for background only and is not intended to convey or imply a comparison to the TOPAZ clinical trial results. CHERISH Trial in Non-Ambulatory Type 2/3 SMA Majority of patients

treated with nusinersen after the age of 5 did not observe an improvement Nusinersen Does Not Increase HFMSE on Average inChildren Who Initiate Treatment After the Age of 5 Years 25

Plateauing of HFMSE Increases Observed After First 15Months of Nusinersen Treatment in Type 2 and 3

SMA 26 "Longer-term treatment with nusinersen: results in later-onset spinal muscular atrophy from the SHINE study" P.257, World Muscle Society Congress 2020This third-party information is provided for background only and is not intended to

convey or imply a comparison to the TOPAZ clinical trial results. Most nusinersen-treated patients in CHERISH were <5 years of age at therapy initiation Mean (+ SE) Change in HFMSE Total Score From Baseline 1 92 169 253 350 450 690

930Analysis Visit, days 1170 1410 1650 876543210-1-2-3-4 Nusinersen observed plateauing of improvement during chronic maintenance phase <1-point increase in HFMSE afterfirst year of treatment +3.9-points +4.6-points Unmet

Need for Motor Function Gains Initial treatmentCHERISH Chronic maintenance phaseSHINE

27 Review of Positive TOPAZ Top-Line Results Yung Chyung, M.D. Chief Medical Officer

Apitegromab Phase 2 Trial Design 28 Patients with Type 2 and 3 SMA Ambulatory Type 3

patients (ages 5-21)Apitegromab 20 mg/kg IV Q4W monotherapy or withchronic nusinersen maintenance Key objectives: RHS and safety at 12 months Non-ambulatory Type 2 patients (ages 2) on chronicmaintenance nusinersen (initiated <5 years

of age)Apitegromab 2 mg/kg and 20 mg/kg IV Q4W + nusinersen Key objectives: HFMSE and safety at 12 months Non-ambulatory Type 2/3 patients (ages 5-21) on chronicmaintenance nusinersen (initiated 5 years of age)Apitegromab 20 mg/kg IV Q4W +

nusinersen Key objectives: HFMSE and safety at 12 months Patients on background SMN therapy were in chronic maintenance phase of nusinersen(~5 mean maintenance doses at baseline) *Excludes one patient from Cohort 1 that discontinued from

the trial All 57* patients who completed the 12-month trial elected to opt into the extension period

Baseline CharacteristicsNusinersen-treated patients well into chronic maintenance

phase 29 Non-Ambulatory,Ages 2 and initiated nusinersen <5 years Non-Ambulatory,Ages 5-21 Ambulatory,Ages 5-21 20 mg/kg+nusinersen 2 mg/kg+nusinersen Pooled 20 mg/kg+nusinersen 20 mg/kg monotherapy 20