Gilead spends $275m on half-share in immuno-oncology firm Pionyr

Gilead chief executive Daniel O’Day (pictured) is on the acquisition trial again, paying $275m for a stake in Pionyr Immunotherapeutics and its pipeline of drugs for patients who don’t benefit from checkpoint inhibitors for cancer.

Gilead has taken a 49.9% stake in South San Francisco-based Pionyr for $275m, plus an option to buy the entire company outright for another $315m fee. Shareholders in Pionyr are also in line for up to $1.15bn in milestones if development of its drug candidates goes according to plan.

It’s yet another bolt-on deal for Gilead, that has already added to its pipeline this year with a ten-year, strategic alliance with Arcus Biosciences valued at $2bn, as well as the purchase of Forty Seven for $4.9bn and smaller deals with oNKo-innate, Second Genome, Teneobio and Rockefeller University.

That crop came after a busy 2019 as well, which included another decade-long, $5.1bn alliance with Galapagos that added dozens of new drug candidates to its portfolio. Crucially, O’Day’s approach to these deals is to leave the partner companies mostly independent, retaining their nimbleness and flexibility.

Gilead’s interest in Pionyr lies in the biotech’s ‘Myeloid Tuning’ therapies – headed by preclinical-stage antibodies PY314 and PY159 – which have shown promising results in combination with PD-1/PD-L1-targeting checkpoint inhibitors.

Gilead says Pionyr is planning to file with the FDA for approval to start clinical testing of both drugs in the third quarter of this year. Gilead’s option kicks in after phase 1b data comes in for either candidate unless it decides to follow through earlier on a takeover.

The drugs are based on lab findings which show that the microenvironment of a tumour – the cells and tissues that surround it – can be manipulated to favour cells that activate immune responses against cancer over those that suppress them.

PY314 and PY159 target TREM2 and TREM1, respectively. Both are found on tumour-associated macrophages (TAMs), a form of white cell, while TREM1 is also observed on tumour-associated neutrophils (TANs). Blocking their activity stimulates an inflammatory response against tumour cells, according to the biotech.

Pionyr’s work in this area stems from the lab of scientific co-founder Max Krummel, from the University of California San Francisco (UCSF), who has described the company’s technology as “the third generation of immuno-oncology, after checkpoint inhibitors and CAR-T therapies”.

Dr Krummel is a co-inventor of Bristol-Myers Squibb’s CTLA4 inhibitor Yervoy (ipilimumab), the first checkpoint inhibitor, which was approved in 2011 to treat melanoma.

“The agreement represents important progress as we continue to build Gilead's presence in immuno-oncology with innovative and complementary approaches,” commented O’Day.

“We look forward to seeing the programmes advance with the goal of developing new therapies that will improve the treatment of cancer.”