Open-label Extension Study to Evaluate Metreleptin in Patients With Partial Lipodystrophy

Inclusion Criteria:

1. Age ≥13 years of age, inclusive, at the time of signing the informed consent form (ICF).

2. Subjects must have completed the Parent study APG-20 and, in the opinion of theInvestigator and Sponsor, have been compliant with study procedures through Parentstudy Month 12 visit.

3. Negative pregnancy test (urine or serum) for female subjects of childbearingpotential

4. Female subjects must be postmenopausal (defined as cessation of menses for at least 1 year), surgically sterile (hysterectomy, bilateral oophorectomy, or tuballigation), or willing to use a highly effective method of contraception (suchmethods include combined [estrogen and progestogen containing] hormonalcontraception associated with inhibition of ovulation: oral/intravaginal;transdermal/progestogen-only hormonal contraception associated with inhibition ofovulation: oral/injectable; implantable/intrauterine device [IUD]/intrauterinehormone-releasing system [IUS]/bilateral tubal occlusion/vasectomized partner/sexualabstinence) for the duration of the study (from the time they sign an ICF, until 4weeks after the last dose of study treatment). Hormonal contraception alone (including oral, injectable, transdermal, and implantable) is not acceptable; anadditional barrier method must be used. Intravaginal hormonal contraception or IUSalone are allowed per Investigator's discretion. Subjects on oral contraceptiveswill not be required to discontinue medication. Subjects will not be permitted tocommence oral contraceptives while taking study treatment during the study.

5. Male subjects must be surgically sterile or willing to use an acceptable method ofcontraception for the duration of the study (from the time they sign an ICF), until 4 weeks after the last dose of study treatment. An acceptable method ofcontraception would be a barrier method, such as condoms, restraining from havingsex, or a partner using the approved methods of contraception for female subjects asper Inclusion Criteria #4.

6. Subjects who are blood/egg/sperm donors should be willing to halt donations duringthe study and for 4 weeks following their last dose of study treatment.

7. Subjects who are willing to provide informed consent/assent prior to anystudy-specific procedures. If a minor, the subject has a parent or legal guardianable to read, understand, and sign the ICF and/or a Child Assent Form (ifapplicable), communicate with the Investigator, and understand and comply with theprotocol requirements. Adolescent subjects must also read and understand the ChildAssent Form.

8. Subjects who are willing to follow the dietary restrictions recommended by theInvestigator.

Exclusion Criteria:

1. Severe hypersensitivity reactions to the study treatment of the Parent study APG-20.

2. Known to have tested positive for human immunodeficiency virus (HIV) or known to bediagnosed with HIV-related LD. Positive HIV test in countries requiring HIV testing.

3. Are immunocompromised or receiving immunomodulatory drugs.

4. Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m2 calculated by ChronicKidney Disease Epidemiology Collaboration (CKD-EPI) for subjects ≥18 years of ageand by Bedside Schwartz for subjects <18 years of age.

5. Diagnosis of clinically significant hematological abnormalities (including but notlimited to clinically significant leukopenia, neutropenia, bone marrowabnormalities, leukemia or lymphoma, or clinically significant pathologicallymphadenopathy).

6. Malignancy that is ongoing/not in remission or that currently requires or hasrequired active treatment within the past year (with the exception of basal cellcarcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ [e.g., breast carcinoma, cervical cancer in situ] that have undergone potentiallycurative therapy).

7. For females only: currently pregnant (confirmed with a positive pregnancy test) orbreastfeeding.

8. Any condition where, in the opinion of the Investigator, participation in this studymay pose a significant risk to the subject.