Intervention: Palovarotene
Trial phase: Phase 2
ATC code: M09AX11
SMILES: CC1(C)CCC(C)(C)c2cc(Cn3cccn3)c(/C=C/c3ccc(C(=O)O)cc3)cc21
Sex: All
Age groups: Child | Adult | Older Adult
Healthy volunteers: No
Participants at risk: 4
Group description: Eligible subjects received a weight-based equivalent dose of palovarotene 10 mg orally once daily for 14 days, followed by 5 mg once daily for 28 days during flare-ups. If treatment was extended beyond 6 weeks (if deemed necessary by the Investigator), a weight-based equivalent dose of 5 mg was to be administered in 2-week increments.
Eligibility criteria:
Inclusion Criteria:

For study enrollment

Completed Study PVO-1A-202 having been treated with palovarotene (ie, 6 weeks on-treatment and 6-weeks follow-up) for two flare-ups.
Written, signed, and dated informed consent or age-appropriate subject/parent assent (this must be performed according to local regulations).

For treatment with palovarotene for subsequent flare-ups

Symptomatic onset of a new, distinct flare-up within 10 days of the first dose of study drug. Symptoms must be reported by the subject, be consistent with their previous flare-ups, and include a subject-reported onset date. The flare-up must be confirmed by the physician at screening via telephone contact and/or video-conferencing.
Females of child-bearing potential (FOCBP) must have a negative blood (or urine) pregnancy test (with sensitivity of at least 50 mIU/mL) prior to administration of palovarotene. Male and FOCBP subjects must agree to remain abstinent during treatment and for 1 month after treatment or, if sexually active, to use two highly effective methods of birth control during and for 1 month after treatment. Additionally, sexually active FOCBP subjects must already be using two highly effective methods of birth control 1 month before treatment is to start. Specific risk of the use of retinoids during pregnancy, and the agreement to remain abstinent or use two highly effective methods of birth control will be clearly defined in the informed consent, and the subject or legally authorized representatives (eg, parents, caregivers, or legal guardians) must specifically sign this section.
Subjects must be accessible for treatment with palovarotene and follow-up.

Exclusion Criteria:

For study enrollment

Any reason that, in the opinion of the Investigator, would lead to the inability of the subject and/or family to comply with the protocol.

For treatment with palovarotene for subsequent flare-ups:

Weight <20 kg.
The flare-up is at a completely ankylosed joint.
Intercurrent non-healed fracture at any location.
If currently using vitamin A or beta carotene, multivitamins containing vitamin A or beta carotene, or herbal preparations, fish oil, and unable or unwilling to discontinue use of these products during palovarotene treatment.
Exposure to synthetic oral retinoids in the past 30 days prior to screening (signature of the informed consent or age-appropriate subject assent).
Concurrent treatment with tetracycline or any tetracycline derivatives due to the potential increased risk of pseudotumor cerebri
History of allergy or hypersensitivity to retinoids or lactose.
Female subjects who are breastfeeding.
Subjects with uncontrolled cardiovascular, hepatic, pulmonary, gastrointestinal, endocrine, metabolic, ophthalmologic, immunologic, psychiatric, clinically significant abnormal laboratory findings, or other significant disease.
Simultaneous participation in another interventional clinical research study within the past 4 weeks (except for Study PVO-1A-202).
Subjects experiencing suicidal ideation (type 4 or 5) or any suicidal behavior within the past month prior to Screening as defined by the Columbia Suicide Severity Rating Scale.
Any reason that, in the opinion of the Investigator, would lead to the inability of the subject and/or family to comply with the protocol.