Gilead picks up small PARP1 biotech to find a mate for Trodelvy and take on Lynparza

Gilead has found a potential friend for breast cancer med Trodelvy in PARP1 and MK2 inhibitor specialist XinThera, which will now come under the Big Pharma's wing. 

The acquisition will add to Gilead’s stable of well-validated targets in oncology and inflammation and bolster its early-stage pipeline, according to a Tuesday press release. Gilead did not disclose the price paid for the privately-held biotech. XinThera previously raised $50 million in an August 2021 series B, bringing its total raise at that time to $80 million.

Gilead is most interested in XinThera’s PARP1 for cancer and MK2 for inflammatory diseases, both programs with small molecules that could enter the clinic this year. Gilead hopes the candidates could provide for multiple indications.

XinThera lists five preclinical candidates on its pipeline: XIN5104 and XIN5789 for HRD+ solid tumors. XIN6301 lists the same indications plus brain tumors. The biotech's MK2 immunology program has XIN5494 and XIN5404 for various autoimmune conditions including rheumatoid arthritis. Other research projects have yet to be disclosed. 

Gilead said that first-generation PARP1/2 inhibitors have shown high efficacy in tumors that have BRCA mutations, including breast, ovarian, prostate and pancreatic cancers. Approved drugs in the class include Merck & Co. and AstraZeneca’s blockbuster Lynparza, which clocked $2.6 billion in sales for the latter company alone in 2022. Other options are Pfizer’s Talzenna, GSK’s Zejula and Clovis Oncology’s Rubraca.

But use has been limited due to toxicities, according to Gilead. XinThera’s candidate offers a more selective PARP1 inhibitor that could lessen the hematological toxicities and perhaps be paired with other chemotherapies or targeted therapies. Gilead name-checked its own Trodelvy as a potential combo option. The therapy just received a new FDA nod in pretreated HR-positive/HER2-negative metastatic breast cancer.

Gilead is ramping up R&D, including a 25% bump in spending during the first quarter. Last year, the Big Pharma laid out a plan to generate one-third of its revenues from oncology products by 2030.