Stickler syndrome (hereditary progressive arthro-ophthalmodystrophy) is a group of rare genetic disorders affecting connective tissue, specifically collagen. Stickler syndrome is a subtype of collagenopathy, types II and XI. Stickler syndrome is characterized by distinctive facial abnormalities, ocular problems, hearing loss, and joint and skeletal problems. It was first studied and characterized by Gunnar B. Stickler in 1965. Signs and symptoms
Individuals with Stickler syndrome experience a range of signs and symptoms. Some people have no signs and symptoms; others have some or all of the features described below. In addition, each feature of this syndrome may vary from subtle to severe.A characteristic feature of Stickler syndrome is a somewhat flattened facial appearance. This is caused by underdeveloped bones in the middle of the face, including the cheekbones and the bridge of the nose. A particular group of physical features, called the Pierre Robin sequence, is common in children with Stickler syndrome. Robin sequence includes a U-shaped or sometimes V-shaped cleft palate (an opening in the roof of the mouth) with a tongue that is too large for the space formed by the small lower jaw. Children with a cleft palate are also prone to ear infections and occasionally  swallowing difficulties.Many people with Stickler syndrome are very nearsighted (described as having high myopia) because of the shape of the eye. People with eye involvement are prone to increased pressure within the eye (ocular hypertension) which could lead to glaucoma and tearing or detachment of the light-sensitive retina of the eye (retinal detachment).
The studies then compared the two groups for the proportion of participants with severe neutropenia (a very low count of white blood cells called neutrophils) and the duration of severe neutropenia in the first cycle of chemotherapy. In all three studies, participants who received trilaciclib had a lower chance of having severe neutropenia compared to participants who received a placebo. Among those who had severe neutropenia, participants who received trilaciclib, on average, had it for a shorter time than participants who received a placebo.The U.S. Food and Drug Administration (FDA) granted the application for trilaciclib priority review and breakthrough therapy designations. The FDA granted the approval of Cosela to G1 Therapeutics, Inc.

References
This article incorporates public domain material from the United States Department of Health and Human Services. External links
"Trilaciclib". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03041311 for "Carboplatin, Etoposide, and Atezolizumab With or Without Trilaciclib (G1T28), a CDK 4/6 Inhibitor, in Extensive Stage Small Cell Lung Cancer (SCLC)" at ClinicalTrials.gov
Clinical trial number NCT02499770 for "Trilaciclib (G1T28), a CDK 4/6 Inhibitor, in Combination With Etoposide and Carboplatin in Extensive Stage Small Cell Lung Cancer (SCLC)" at ClinicalTrials.gov
Clinical trial number NCT02514447 for "Trilaciclib (G1T28), a CDK 4/6 Inhibitor, in Patients With Previously Treated Extensive Stage SCLC Receiving Topotecan Chemotherapy" at ClinicalTrials.gov