Is Parental Consent Valid for Minor Children?

Anew oral retinoid has been FDA cleared for the treatment of psoriasis. It has been shown to be safer than all previously available retinoids. Dr. Doe learned that this medication has been used safely in Europe for the prevention of acne in pre-adolescent teenagers. He has a large adolescent practice and is excited about using this medication on his young patients. Recognizing that the drug does not have FDA clearance for his intended use, he asks parents of prospective patients to sign a consent form allowing him to use this potentially miraculous drug on their children. Is the consent of the parent valid?