Beijing, China, May 29, 2020 - 3D Medicines announced that the data from two clinical trials on Envafolimab (KN035) will be published on the 2020 annual meeting of American Society of Clinical Oncology (ASCO).

Envafolimab (KN035) is a subcutaneous PD-L1 antibody co-developed by 3D Medicines (Beijing) Co., Ltd., a wholly-owned subsidiary of 3D Medicines, Inc., and Jiangsu Alphamab Biopharmaceuticals Co., Ltd. (Stock code: 9966. HK), and the clinical trials in discussion evaluated Envafolimab (KN035) monotherapy in advanced solid tumors with microsatellite instability-high (MSI-H)/mismatch repair deficiency (dMMR) as monotherapy, and a combination therapy with KN035 plus chemotherapy for advanced gastric or gastroesophageal junction (G/GEJ) cancer.

According to the partnership agreement, 3D Medicines is responsible for the global clinical development, registration and commercialization of KN035 for tumor indications. Alphamab is the exclusive manufacturer of KN035 and responsible for the production and supply of KN035. Simcere will obtain the exclusive right to promote KN035 in mainland China upon the approval of NDA. Detailed data will be published simultaneously on the company's website (www.3d-medicines.com) on May 29, 2020.

The pivotal clinical trial of Envafolimab for the treatment of advanced solid tumors with MSI-H/dMMR enrolled 103 patients. The study is a single-arm, open-label pivotal clinical trial, with the objective response rate (ORR) per RECIST v1.1 by independent radiology review as the primary endpoint. MSI-H/dMMR status was assessed centrally for colorectal cancer (CRC) and gastric cancer (GC) and locally for other tumors. Please see the picture below for more details.

The data from Envafolimab (KN035) in advanced tumors with mismatch-repair deficiency (ASCO abstract number: 3021) is published, as of December 17, 2019. Highlights include:

103 patients with MSI-H/dMMR advanced cancer were enrolled at 25 centers in China. The primary efficacy population (PEPi) that received at least two post-baseline tumor assessments consisted of 39 patients with advanced CRC who had previously received therapies with at least fluoropyrimidine, oxaliplatin and irinotecan and 11 patients with advanced GC who had previously received at least first-line standard therapy, with a median follow-up time of 7.5 months. The overall population (n=103) included 65 patients with CRC (24 previously treated with fluoropyrimidine, oxaliplatin or irinotecan), 18 with GC and 20 with other tumors, with a median follow-up time of 6.7 months.

· The confirmed objective response rate (ORR) was 30% (95% CI: 17.9%, 44.6%) in the PEPi, with 80% of those still responding at the time of data cutoff.

· The confirmed ORR was 54.2% (95% CI: 32.8%, 74.4%) in the CRC patients previously treated with fluoropyrimidine, oxaliplatin or irinotecan, with 84.6% of those still responding at the time of data cutoff.

· The confirmed ORR was 34.0% (95% CI: 24.9%, 44.0%) in the overall population, with 85.7% of those still responding at the time of data cutoff.

· Median progression-free survival was 6.6 months in both the PEPi and the overall population. Median overall survival was not reached in both populations. Grade 3-4 treatment-related adverse events (TRAE) occurred in 14 patients (13.6%). No reports of grade 5 TRAE, pneumonitis, or colitis were reported. Local injection site reaction occurred in 9 patients, all of which were grade 1 or 2.

Envafolimab plus chemotherapy in advanced gastric or gastroesophageal junction (G/GEJ) cancer （ASCO abstract number： 16585）explores the safety and efficacy of Envafolimab plus chemotherapy in advanced gastric or gastroesophageal junction (G/GEJ) cancer. Data highlights include:

A total of 15 subjects were treated and evaluable for response. ECOG performance status was 1 in 80% of subjects. The majority had gastric cancer (86.7%). At the time of data cutoff, the minimum follow-up was 6 months.

· The treatment emergent adverse event (TEAE) occurrence was 100% (all grades) and 73.3% (grades 3-4). The most frequent grade 3-4 TEAE included neutrophil count decrease (46.7%), anemia (20.0%), and platelet disorder (20%, 3/15).

· Confirmed ORR was 60% (unconfirmed ORR: 73.3%).

· Median duration of response (DOR) was not reached. Median progression-free survival (PFS) was 6.8 months.

John Gong, M.D., Ph.D., Chairman and CEO of 3D Medicines, commented:” Envafolimab is the first subcutaneous PD-L1 antibody to enter a pivotal clinical trial. In the first pivotal clinical trial of biomarker-based subject selection that 3D Medicines has conducted in China, Envafolimab has demonstrated significant durable efficacy with a favorable safety profile for the treatment of MSI-H/dMMR advanced cancer patients who had failed standard therapy. 3D Medicines looks forward to working together with Alphamab, Simcere and Tracon to bring Envafolimab to market as soon as possible, offering a new, convenient treatment option for patients with this type of cancer.

About Envafolimab （KN035）

Envafolimab (KN035) is a PD-L1 single-domain antibody Fc fusion protein. Based on the unique design, Envafolimab (KN035) has advantages in safety, convenience and compliance, and can be used for the patients who are not suitable for intravenous infusion with a lower medical cost. Envafolimab is independently invented by Alphamab. In 2016, 3D Medicines and Alphamab signed a collaborative development agreement and 3D Medicines would be responsible for global clinical development in the field of oncology, registration, global market development and commercialization. In the past four years, Envafolimab (KN035) has been simultaneously tested in clinical trials for multiple cancer indications in China, the United States and Japan, and some indications have entered pivotal clinical researches. Envafolimab (KN035) has been awarded Orphan Drug Designation by FDA and the marketing application to NMPA is planned to be submitted in 2020. Simcere, 3D Medicines and Alphamab reached a collaboration agreement on its commercialization in China in the same year.

About 3D Medicines

3D Medicines, Inc. is a clinical-stage biopharmaceutical company with a mission to help people with cancer live longer and better. Envisioning a future when cancer is managed as a chronic disease, 3D Medicines focuses on the development of differentiated next-generation immuno-oncology drugs, helping cancer patients live with prolonged survival time and a better quality of life. 3D Medicines has established a pipeline with both next-generation biological macromolecule and chemotherapeutic small-molecule drugs, as well as a professional team capable of global development, registration and commercialization operation.