How Chinese and Overseas Enterprises Catch the Next Immunotherapy Wave

The complex interplay between tumor cells and immune system is becoming increasingly clear, and the clinical efficacy of tumor immunotherapies like immune checkpoint inhibitors has been verified, however, overall, the tumor response rate is not high. New breakthroughs are urgently needed in the tumor immunity field. Oncolytic viruses can selectively replicate in tumor cells to turn "cold" tumors into "hot" ones, strengthen immunogenicity of the tumor microenvironment, and boost immune response; they are expected to become an effective combination of immune checkpoint inhibitors such as PD-1 inhibitors.

1.    What are oncolytic viruses

Oncolytic viruses are a kind of virus that can naturally or, after gene editing, specifically replicate in tumor cells to exert the antitumor effect. Oncolytic viruses selectively replicate and proliferate in tumor cells, and cause tumor cell death through apoptosis and autophagic death, etc.; the dead tumor cells will release antigens to trigger natural and acquired immune responses and strengthen systemic antitumor effect.

2.    Advantages of oncolytic viruses compared to other immunotherapies

• Selectively replicate in tumor cells to turn "cold" tumors into "hot" ones, strengthen immunogenicity of the tumor microenvironment, and trigger extensive antitumor immune responses
• Have a multi-path killing mechanism, act in many links of tumor immunity, and have broad-spectrum antitumor activity
• Have high safety and small toxic and side effects, which benefits their combination with other immunotherapies and other antitumor drugs
• Have lower production costs and incur less treatment costs compared to cellular immunotherapies such as CAR-T

3.    Oncolytic viruses approved for marketing

Sales of the oncolytic virus products approved for marketing are not impressive because their administration route is limited only to intratumoral injection, and more importantly, the monotherapy has a limited response rate, and the approved indication is mainly melanoma, making them uncompetitive compared to the PD-1 inhibitors in that field.

Oncolytic Viruses Approved for Marketing

4.    International research progress and layout of international pharmaceutical giants in the oncolytic virus field

Relevant products currently in Phase III clinical studies mainly include ProstAtak (Advantagene), CG0070 (Cold Genesys), Pexa-vac (Jennerex Biotherapeutics), and Reolysin (Oncolytics Biotech).

International Oncolytic Virus Products in Clinical Development

Amgen acquired BioVex in 2011 by paying USD 425 million upfront, plus USD 575 million in milestone payments, to obtain T-vex, and has made it the first oncolytic virus marketed in the U.S.

AstraZeneca reached a licensing agreement with Omnis in 2015, to allow key agents from its immunotherapy portfolio to be used and developed in combination with Omnis’ main product: VSV.

BMS acquired the worldwide commercial license for NG-348, a product of Psioxus Therapeutics, in 2016 by paying USD 50 million upfront and up to USD 886 million in milestone payments; the Phase I clinical trial of the combination of NG-348 and Opdivo is underway.

Transactions of oncolytic viruses have been more frequent in 2018: Merck has acquired Viralytics to obtain the product Cavatak, and expects it to be used in combination with Keytruda; J & J has acquired BeneVir, to obtain the T-Stealth™ oncolytic virus platform; Boehringer Ingelheim has acquired ViraTherapeutics for EUR 210 million after two years of cooperation therewith, to obtain the core product VSV-GP.

Transaction Situation of International Pharmaceutical Giants on Oncolytic Virus Products