Orphan Drug designation in the United States is granted to drugs or biologics intended to treat, prevent, or diagnose rare diseases or conditions, defined as those affecting under 200,000 Americans. Once granted this status, the drug developer also earns incentives: increased regulatory assistance, fee waivers, tax credits, and 7 years of market exclusivity upon approval. According to OncLive, toripalimab recently earned Orphan Drug designation for the treatment of esophageal cancer.
Toripalimab
So what exactly is toripalimab? According to Coherus Biosciences, toripalimab is:
an anti-PD-1 monoclonal antibody developed for its ability to block PD-1 interactions with [tumor checkpoint proteins], PD-L1 and PD-L2, and for enhanced receptor endocytosis function. Blocking PD-1 interactions with PD-L1 and PD-L2 is thought to recharge the immune system’s ability to attack and kill tumor cells.
Orphan Drug designation was granted following data from the Phase 3 JUPITER-06 clinical trial. Within the trial, researchers evaluated the efficacy of toripalimab plus platinum-based chemotherapy in treating patients with esophageal squamous cell carcinoma in comparison to just chemotherapy. Altogether, 514 patients enrolled. Patients either received 240mg toripalimab with 175mg/m2 paclitaxel and 75mg/m2 cisplatin or a placebo with the latter two. Findings include:
- Toripalimab reduced the risk of esophageal cancer progression by 42%.
- Additionally, toripalimab significantly increased progression-free survival over both a one- and two-year period.
- While the drug was relatively effective, approximately 64.6% of patients using taking toripalimab experienced Grade 3 or higher toxicities, including fatigue, nausea and vomiting, appetite loss, hair loss, peripheral neuropathy, leukopenia (low leukocyte levels), neutropenia (low neutrophil levels), and anemia (low red blood cell count).
Esophageal Cancer
As the name suggests, esophageal cancer begins in the esophagus, which runs from your throat to your stomach. The esophagus is made up of numerous tissue layers. Esophageal cancer normally begins in the inner cell lining and spreads outward. Esophageal adenocarcinoma is the most common form of this cancer in the United States, while esophageal squamous cell carcinoma is the most common form worldwide. Other rare forms include esophageal melanoma, esophageal lymphoma, choriocarcinoma, and sarcoma. Risk factors for developing esophageal cancer include being obese, excessive alcohol consumption, smoking, being male, or having acid reflux or gastroesophageal reflux disease (GERD). Symptoms usually do not appear until later stages. These include:
- Unintended weight loss
- Esophageal obstruction
- Chest pain or pressure
- Difficulty swallowing (and/or painful swallowing)
- Poor indigestion
- Heartburn
- Chronic cough
- Hoarse voice
- Bone pain
Learn more about esophageal cancer.
