Pfizer to acquire 9.9% stake in CStone for $200m

30 September 2020 (Last Updated October 1st, 2020 06:43)

CStone Pharmaceuticals has entered into a strategic partnership with Pfizer to develop and commercialise late-stage oncology therapies in China.

Pfizer to acquire 9.9% stake in CStone for $200m
Sugemalimab is being developed for high-incidence cancer indications in China. Credit: Colin Behrens from Pixabay.

CStone Pharmaceuticals has entered a strategic partnership with Pfizer to develop and commercialise late-stage oncology therapies in China.

Under the deal, Pfizer Hong Kong will invest $200m in CStone, acquiring 115,928,803 CStone shares at $1.725 per share. This equity investment will provide Pfizer with a 9.9% stake in CStone.

The companies will work together to develop and commercialise CStone’s drug candidate sugemalimab (CS1001) in mainland China.

Sugemalimab is a potential anti-PD-L1 monoclonal antibody. The drug candidate mimics the G-type immunoglobulin 4 (IgG4) human antibody, which may decrease immunogenicity and toxicity risks in patients.

The drug candidate could potentially treat high-incidence cancers in China, including lung, gastric and oesophageal cancers, among others.

A Phase I dose-escalation trial of sugemalimab took place in China. In Phase Ia and Ib stages, the drug candidate demonstrated anti-tumour activity in various tumour types and proved well-tolerated.

As part of the collaboration, CStone will get financing support for developing sugemalimab.

Pfizer will in-license the drug candidate and hold exclusive commercialisation rights in mainland China, while CStone will be responsible for clinical development and regulatory strategy for five selected indications.

Under the agreement, CStone is eligible for up to $280m in milestone payments for sugemalimab, along with royalties. The company will hold all development and commercialisation rights outside mainland China.

This deal will allow the companies to select and jointly develop additional late-stage oncology assets in the Greater China market. These assets could also be from Pfizer’s pipeline or joint in-licensing.

CStone Pharmaceuticals chairman and CEO Frank Jiang said: “By joining forces with Pfizer and leveraging its commercialisation infrastructure, we will ensure that patients across a vastly expanded number of markets in China have quicker access to our highly differentiated PD-L1 treatment.”

Goldman Sachs is the financial adviser to CStone while Cooley served as legal advisor. Pfizer’s legal adviser was Clifford Chance.

In January, Pfizer signed an exclusive worldwide licence and collaboration agreement with eFFECTOR in the oncology field.