Yingli Pharma Announces a presentation on the Phase 2 clinical trial of linperlisib, a PI3Kδ selective inhibitor, in relapsed or refractory follicular lymphoma at the European Hematology Association 2

Shanghai Yingli Pharmaceuticals Ltd (Yingli Pharma), a clinical stage pharmaceutical company providing new therapies for cancer and metabolic diseases, announced today the topline data from a clinical trial sponsored by the company at the annual meeting of the European Hematology Association (EHA) being held June 9-17, 2021.

The study entitled 'A Phase 2 study of an oral PI3Kδ inhibitor YY-20394 in patients with relapsed or refractory follicular lymphoma' will be presented at EHA by Dr. Lugui Qiu, a lead investigator from Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin, China. This is a registration study that enrolled 93 relapsed or refractory Follicular Lymphoma (FL) patients having received 2 or more prior systemic therapies and was conducted at 32 clinical sites in China. Linperlisib was evaluated as a monotherapy for safety, tolerability and efficacy at recommended phase 2 dose of 80 mg once daily. Following a data cutoff on March 15, 2021, the fully enrolled study was analyzed for 89 evaluable patients. The Overall Response Rate (ORR) was 79.5%, with 12.4% Complete Response, 67.4% Partial Response, and 16.1% Stable Disease, combining to achieve a Disease Control Rate of 96.6%. Previously, the Phase 1 study of linperlisib had shown similar preliminary efficacy of 90% ORR in 10 patients with r/r FL. As of the data cutoff for the Phase 2, the median Progression Free Survival was 11.8 months, and the Duration of Response was 12.3 months. Forty seven  patients were continuing to receive linperlisib treatment.

Follicular Lymphoma is increasingly harder to treat if patients progress on previous therapies, usually immuno-chemotherapy is a mainstay as a prior treatment. On this study, 65% of the patients had received 3 or more prior systemic treatments, and all patients had previously received rituximab-based therapies.

The safety data from the FL Phase 2 study indicated that linperlisib was generally safe and tolerable with manageable adverse events.  Most of the adverse events were Grade 1 and Grade 2. The most common (>5%) treatment related hematologic adverse events of ≥ Grade 3 were neutropenia (15.1%), leukocytopenia (5.4%), lymphocytopenia (5.4%). The most common (>5%) treatment related non-hematologic adverse events of ≥ Grade 3 were pneumonia (15.1%).

Dr. Lugui Qiu, a prinicipal investigator on the study, stated "FL is complicated as the relapsed and refractory patients tend to progress rapidly, requiring aggressive therapies. From the clinical findings with linperlisib treatment of FL patients, we are seeing durable responses for most patients. Patients are in desperate need of effective therapies that target these lymphoma key signaling pathways and therapies that are oral medications, easy for patients to use outside of a clinic."

Dr. Zusheng Xu, General Manager of Yingli Pharma commented "We are excited to be developing Linperlisib for the treatment of lymphomas and solid tumors. Linperlisib is a next-generation PI3Kδ-selective inhibitor. The clinical data suggest that Linperlisib might be a potentially advantageous treatment option for patients. We have applied a linperlisib marketing approval in China in relapsed or refractory FL, based on the data from this phase II registration study. We hope to broaden the use of linperlisib and are exploring its anti-tumor activities in different indications in additional clinical trials."

Dr. Qiu also indicated "It is a major step that Linperlisib has been accepted by the NMPA for the NDA application, and we are very optimistic about the outcome."

About Linperlisib

Linperlisib (YY-20394) is a highly selective and potent PI3Kδ inhibitor that has shown a favorable safety profile, exciting anti-tumor activities, and good PK and pharmaceutical properties as an oral once-a-day agent in late-stage clinical development. A phase 1 clinical trial was completed in 2020 demonstrating linperlisib to be a safe and tolerable agent, and a recommended phase 2 dose of 80 mg QD was established. Linperlisib was awarded NMPA Breakthrough Therapy status in China, leading to the current trial.  In addition, linperlisib received FDA Orphan Drug Designations for FL, CLL/SLL, and T cell lymphoma. A clinical trial in r/r FL is launching in the US. Multiple linperlisib clinical trials being conducted in other lymphomas, solid tumors, and in combination with gemcitabine/oxaliplatin in r/r DLBCL. Preliminary results from a PTCL Phase1b study were reported at ASCO 2021, indicating an overall response rate of 70% with 33% CRs in 30 evaluable patients with r/r PTCL, a difficult to treat and aggressive form of lymphoma.

About Yingli Pharma

Yingli Pharma, headquartered in Shanghai with a subsidiary in San Francisco, is an innovative clinical stage biopharmaceutical company. Yingli Pharma is developing best-in-class and first-in-class oral investigational agents for the treatment of cancer, metabolic and autoimmune diseases. Yingli Pharma currently has three investigational agents in clinical development, linperlisib (YY-20394) and YL-13027 in advanced cancers, as well as YL-90148, an investigational oral URAT-1 inhibitor for the treatment of in hyperuricemia/gout. Several additional oncology programs are in IND-enabling or candidate development stages.