Efficacy and Safety of the MC4R Agonist in LEPR Deficiency : A Phase 3 Trial

Erica van den Akker,1 Karine Clément,2,3 Wendy K. Chung,4,5 Sadaf Farooqi,6 Julie Gonneau-Lejeune,7 Greg Gordon,8 Jim Murray,8 Guojun Yuan,8 Martin Wabitsch9

1Division of Pediatric Endocrinology, Department of Pediatrics, Sophia Children’s Hospital and Obesity Center CGG, Erasmus University Medical Center, Rotterdam, the Netherlands; 2Sorbonne Université, INSERM, Nutrition and Obesities Research Unit, Paris, France; 3Assistance Publique Hôpitaux de Paris, Pitié- Salpêtrière Hospital, Nutrition Department, Paris, France; 4Department of Pediatrics, Columbia University, New York, NY; 5Department of Medicine, Columbia University, New York, NY; 6Wellcome-MRC Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, United Kingdom; 7Université de la Réunion, Unité Transversale de Nutrition Clinique, CHU de la Réunion, Réunion, France; 8Rhythm Pharmaceuticals, Inc., Boston, MA; 9Division of Pediatric Endocrinology and , Department of Pediatrics and Adolescent Medicine, University of Ulm, German y The Regulation of Body Weight Is Complex

Body weight is determined by the balance between food intake and energy Satiety expenditure1 Feeding The regulates both aspects in response to cues from peripheral hormones that reflect nutritional state1,2

Energy output

Circulating hormones

BMI, body mass index. 1. van der Klaauw and Farooqi. Cell. 2015;161:119-132. 2. Cummings et al. Diabetes. 2001;50:1714-1719. 2 Figure adapted from Morton et al. Nat Rev Neurosci. 2014;15:367-378. Leptin- Signaling Is Crucial for Regulation of Body Weight

• The (MC4R) is a component of the central melanocortin pathway in the hypothalamus and is a key regulator of energy intake, expenditure, and body weight1,2 • Leptin is a satiety hormone that binds to leptin receptors (LEPR), resulting in MC4R-mediated reduction in food intake1 • Genetic variants in LEPR are rare and present with early-onset severe obesity and hyperphagia1,3

Hypothalamus AgRP/NPY Neuron LEPR Hunger AgRP Food Intake ADIPOSE Weight TISSUE MC4R- Energy Expressing Expenditure MC4R Neuron LEPTIN PCSK1

BLOOD-BRAIN POMC α-MSH BARRIER LEPR POMC Neuron

ACTH, adrenocorticotropic hormone; AgRP, agouti-related protein; LEPR, leptin receptor; MC4R, melanocortin 4 receptor; MSH, melanocyte-stimulating hormone; NPY, neuropeptide Y; PCSK1, proprotein convertase subtilisin/kexin type 1; POMC, . 3 1. Yazdi et al. PeerJ. 2015;3:e856. 2. Shen et al. Biochim BiophysActa Mol Basis Dis. 2017;1863:2477-2485. 3. Farooqi and O’Rahilly. J Endocrinol. 2014;223:T63-T70. Setmelanotide Is an MC4R Agonist That Targets the Impaired Central Melanocortin Pathway

Results from a phase 2 trial showed that setmelanotide, an MC4R peptide agonist, reduced weight in 3 patients with LEPR deficiency obesity1

This multicenter, placebo-controlled, phase 3 trial investigated the efficacy and safety of setmelanotide in individuals with LEPR deficiency obesity

LEPR, leptin receptor; MC4R, melanocortin 4 receptor. 4 1. Clément et al. Nat Med. 2018;24:551-555. Phase 3 Study Design

Primary endpoint: Dose Titration Open-label Treatment and Withdrawal • Proportion of participants who achieved ≥10% weight loss Screening Establish therapeutic Early Key secondary endpoints: Open-label Open-label dose of daily self- Withdrawal termination treatment at treatment at • Mean percent change in body Days administered sequence or weight therapeutic dose therapeutic dose -28 to -1 setmelanotide follow-up • Mean percent change in “most hunger” scorea • Proportion of participants who End of achieved ≥25% reduction in “most 10 weeks 8 weeks 32 weeks hunger” score Variable duration study 2-12 weeks Post hoc analysis: Start of Week 52 • BMI Z-scores for participants aged week 3 <19 years Last dose

Participants who lost ≥5 kg weight (or ≥5% if <100 kg) in the first open-label active treatment phase entered an 8-week, placebo-controlled phase, inclusive of a 4-week placebo withdrawal period

BMI, body mass index. 5 a“Most hunger” score was determined on a 0 to 10 Likert scale from the question, “In the last 24 hours, how hungry did you feel when you were the most hungry?” Enrollment Criteria

Key Inclusion Criteria Key Exclusion Criteria

• Biallelic for loss-of-function LEPR variants • Recent diet and/or exercise regimen (homozygote or compound heterozygote) resulting in weight loss or stabilization

• Adults (aged ≥18 years) with BMI of • Prior gastric bypass surgery resulting in 2 ≥30 kg/m >10% weight loss with no evidence of • Children or adolescents (aged weight regain ≥6 years to <18 years) with weight of • Psychiatric or medical issues that would >97th percentile for age confound study results

6 BMI, body mass index; LEPR, leptin receptor. Eleven Participants With LEPR Deficiency Obesity Were Enrolled

Baseline characteristics (n=11) Age, mean (range), years 23.4 (12-37)

Male, n (%) 3 (27) Genotype, n (%) 6 (55) Compound heterozygous 5 (45) Homozygous Ethnicity, n (%) White 10 (91) South Asian 1 (9)

Weight, mean (range), kg 133.3 (89.4-170.4)

BMI, mean (range), kg/m2 48.2 (35.8-64.6)

“Most hunger” score, mean (range)a 7.1 (5-8)

9 participants completed the trial; 2 participants discontinued

BMI, body mass index; LEPR, leptin receptor. 7 a“Most hunger” score was determined on a 0 to 10 Likert scale from the question, “In the last 24 hours, how hungry did you feel when you were the most hungry?” Setmelanotide Was Associated With Significant Weight Reductions Over ~1 Year at Therapeutic Dose

25%

20%

15% 5 of 11 participants (45%; 90% CI: 19.96% to 10% 72.88%); P=0.0001) 5% achieved the primary endpoint threshold of 0% ≥10% weight loss from Mean percent change in baseline -5% body weight from baseline was -12.5% (n=7a; 90% CI: -10% -23.3% to 0.09%); P<0.0001; -15% mean weight loss was -16.7 kg)

-20%

% Change in body weight % Change body in therapeutic at weight ~1 from year dose -25%

Population includes imputed data based on linear mixed effect model from n=1 participant who died from a car accident. CI, confidence interval. 8 aEndpoint was analyzed on evaluable population (n=7), which included participants who achieved 5 kg (5% if <100 kg) body weight loss threshold after open-label period 1. Setmelanotide Was Associated With Significant Reductions in “Most Hunger” Score Over ~1 Year at Therapeutic Dose

“Most hunger” score parameter (n=7)a Mean (SD) Range Baseline 7.0 (0.77) 6.0 to 8.0

~1 year at therapeutic dose 4.1 (2.09) 2.0 to 8.0

Percent change from baseline, % -43.7 (23.7) -67.0 to 0 P value P<0.0001

8 out of 11 participants (73%) had ≥25% reduction in “most hunger” scores from baseline (P<0.0001)

SD, standard deviation. “Most hunger” score is based on 0 to 10 Likert scale from the question, “In the last 24 hours, how hungry did you feel when you were the most hungry?” 9 aEndpoint was analyzed on evaluable population (n=7), which included participants who were aged ≥12 years and who achieved 5 kg (5% if <100 kg) body weight loss threshold after open-label period 1. Example 1 of 2 of Single Patient Body Weight and Hunger Curve Over 1 Year Setmelanotide 0 dose, mg 0.5 1.0 1.5 2.0 (placebo) 2.0 2.5 0 -1.6 10 -1.3 -4.4 -5.9 9 -7.9 Weeklyaverage dailyscorehungerof 8 -10 7 -13.6 hungry mostwhen -12.3 6 -16.5 -20 -18.1 5

-21.9 -25.9 4 -28.1 3 -30 -27.8 Weight change from baseline baseline (kg)from change Weight 2

1 Baseline weight: 120.5 kg -40 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68

Primary endpoint Week

10 Example 2 of 2 of Single Patient Body Weight and Hunger Curve Over 1 Year Setmelanotide 0 Dose, mg 1.0 1.5 2.0 2.5 3.0 (placebo) 3.0 0 -2.4 10 -0.2 -3.9 -4.4 -3.7 -3.6 -3.5 9 -4.3 Weeklyaverage dailyscorehungerof -5.8 -6.6 -10 -7.5 -6.5 -7.1 -6.7 8 -8.7

7 when most hungry hungry mostwhen

-20 6

5

-30 4

3

Weight change from baseline baseline from change (kg) Weight -40 2

1 Baseline weight: 153.4 kg -50 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60

Subject did not meet primary endpoint. Week

11 Setmelanotide Withdrawal During the Placebo Sequence Was Associated With Increases in Weight and Hunger Score

+4.97 kg +3.1

n=7 n=6 Range: +2.85 kg Range: 4.0 to 10.0 to +9.03 kg

Absolute Absolute mean mean weight “most hunger” score increase

12 Setmelanotide Was Associated With Reductions in BMI and BMI Z-Score Over ~1 Year at Therapeutic Dose

Participants aged ≥19 years (n=8)* Participants aged <19 years (n=3) Mean change from baseline: -5.2 kg/m2 Mean change from baseline: -0.49 Mean % change from baseline: -10.6% (P=0.01) Mean % change from baseline:-13.35% (P=0.012) 4 60 3.52 51.18 45.82 3.03 50

3 score 40 -

2

30 Average BMI Z Average

Average BMI (kg/m2)Average 20 1

10

0 0 Baseline ~1 year at therapeutic dose Baseline ~1 year at therapeutic dose* BMI, body mass index. *One participant was not included in the ~1 year measurement due to discontinuation due to treatment-related adverse event. Population includes imputed data based on linear mixed effect model from n=1 participant who died from a car accident after 26 weeks at therapeutic dose. BMI baseline analysis includes n=1 participant who withdrew from the study. 13 Error bars are the standard error of the mean, which was calculated by dividing the standard deviation by the square root of n. Effect of Setmelanotide on BMI and BMI Z-score

Percent change from ~1 year at therapeutic dose baseline, % (SD); Baseline (SD) (SD) P value BMI (kg/m2) of participants aged 51.18 (10.67) 45.82 (11.48)a -10.59 (8.11) ≥19 years (n=8) P=0.01

BMI Z-score of participants aged 3.52 (0.36) 3.03 (0.08) -13.35 (8.87) <19 years (n=3) P=0.12

Setmelanotide was associated with a significant reduction in BMI

BMI, body mass index; SD, standard deviation. Population includes imputed data based on linear mixed effect model from n=1 participant who died from a car accident. 14 aN=7; one participant discontinued due to treatment-related adverse event. Setmelanotide Was Well Tolerated in Individuals With LEPR Deficiency Obesity

Parameter n (%) • One participant discontinued due to Treatment-related AEs 11 (100) mild hypereosinophilia related to Injection-site reaction 11 (100) setmelanotide treatment Hyperpigmentation 8 (73) Nausea 5 (45) • One participant died in a car accident (passenger), and the event was not Serious AEs 3 (27) related to treatment Serious treatment-related AEsa 0 • Setmelanotide was not associated with Treatment-related AEs leading to 1 (9) significant changes in blood pressure discontinuation or heart rate b AEs leading to death 1 (9) • There were no reported cardiovascular AEs related to setmelanotide

AE, adverse event; LEPR, leptin receptor. aFour serious AEs occurred in 3 patients, including cholecystitis, road traffic accident, suicidal ideation, and gastric banding reversal. bParticipant died in a road traffic accident (passenger) 15 unrelated to setmelanotide treatment. Effect of Setmelanotide on Vital Signs

Percent change from baseline, %; Baseline ~1 year at therapeutic dose P value Diastolic blood pressure (mmHg) 67.67 (5.83) 66.48 (8.59) -1.58 (13.04) P=0.73

Systolic blood pressure (mmHg) 121.70 (8.84) 115.11 (14.57) -3.78 (9.94) P=0.29

Heart rate (beats/min) 79.46 (12.60) 77.89 (16.46) -1.32 (15.46) P=0.80

Setmelanotide was not associated with changes in blood pressure or heart rate

mmHg, millimeter of mercury; SD, standard deviation. Data are shown as mean (SD) for n=9 participants.

16 • In this phase 3 study, 45% of participants achieved the primary endpoint of ≥10% weight loss from baseline at ~1 year from therapeutic dose

Conclusions: • Setmelanotide was associated with clinically meaningful weight Setmelanotide Reduced loss and reduction in “most hunger” score Hunger and Body Weight • Withdrawal from setmelanotide during the placebo phase was associated with significant increases in weight and “most hunger” and Was Well Tolerated in score Individuals With LEPR • Setmelanotide was generally well tolerated Deficiency Obesity • This study is one of two phase 3 trials supporting the potential use of setmelanotide for the treatment of early-onset severe obesity and hyperphagia

• The second phase 3 trial supports the potential use of setmelanotide in individuals with POMC or PCSK1 deficiency obesity

17 PCSK1, proprotein convertase subtilisin/kexin type 1; POMC, proopiomelanocortin.