An Orphan Drug designation is granted to drugs or biologics intended to treat patients with rare diseases or conditions, affecting less than 200,000 Americans. Because it can sometimes be difficult to develop drugs for rare conditions, the Orphan Drug program offers incentives for drug development, such as 7 years of market exclusivity (once approved), fee waivers, tax credits, and increased FDA regulatory assistance. In a recent press release, biopharmaceutical company TRACON Pharmaceuticals (“TRACON”) shared that its therapy envafolimab (KN035), designed to treat patients with soft tissue sarcoma, was granted Orphan Drug designation.

Envafolimab

So what is envafolimab? According to TRACON, the therapy is:

a novel, single-domain PD-L1 antibody that is administered by subcutaneous injection without the need for an adjuvant.

The Orphan Drug designation hinged upon an amended application with Phase 1 clinical trial data. From this trial, researchers determined that:

• Patients from the trial experienced sustained, durable responses over a 6-month period.
• Altogether, envafolimab showed a 40% response rate. Compared to the 42% response rate of Tecentriq, the current standard-of-care in regards to PD-L1 antibody treatment, this is incredibly promising.

Thus far, envafolimab has been evaluated in a number of Phase 2 and Phase 3 clinical trials. One such trial is the Phase 2 ENVASARC trial, which is evaluating envafolimab as a monotherapy and in conjunction with ipililumab for patients with undifferentiated pleomorphic sarcoma or myxofibrosarcoma. Altogether, 160 patients will enroll. During the trial, patients will receive either envafolimab or envafolimab with Yervoy.

An additional Phase 3 trial is being held in China and is sponsored by Alphamab Oncology (“Alphamab”) and biopharmaceutical company 3D Medicines, both partners of TRACON. Finally, these companies also submitted a New Drug Application (NDA) in China which was granted Priority Review status in January 2021.