Merck & Co. has acquired exclusive global rights to develop, manufacture, and commercialize SciBrunch Therapeutics’ preclinical oral precision cancer candidate SPR2015, through a licensing and collaboration deal that could generate up to $2.13 billion for the Chinese small molecule oncology drug developer.
SPR2015 is a preclinical molecular glue, more specifically an oral KRAS G12D (ON) inhibitor that SciBrunch is developing for forms of cancer that include colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and pancreatic ductal adenocarcinoma (PDAC)—the most common and aggressive type of pancreatic cancer.
KRAS G12D is the most common oncogenic RAS mutation in human tumors—with a 38% prevalence in pancreatic cancer, CRC, and NSCLC, according to a 2023 study. The mutation results from a substitution of glycine with aspartate at position 12, a change that leaves KRAS active and continuously signaling for cell proliferation and survival, SciBrunch said.
According to SciBrunch, SPR2015 has shown nanomolar antiproliferative activities in various KRAS G12D-mutant cell lines while maintaining good selectivity over KRAS wildtype cells.
At the 2026 American Association for Cancer Research (AACR) Annual Meeting, a team of SciBrunch researchers that included founder, chairman, and CEO Tao Hu, PhD, presented preclinical data showing SPR2015 to have demonstrated what it termed compelling antitumor efficacy as a monotherapy across multiple in vivo cell-derived and patient-derived xenograft (CDX and PDX) models.
“SPR2015 is a highly potent and selective KRAS G12D (on) inhibitor with nanomolar proliferation inhibitory activities in various KRAS G12D cell lines while with good selectivity over KRAS wild type,” Hu and SciBrunch researcher colleagues reported in a poster presentation during AACR 2026. They added that PR2015 was expected at the time to human Phase I studies by the end of this year.
In a head-to-head mouse study comparing a single oral once-daily dose at 100 mg/kg of SPR2015 to another unspecified G12D (ON) inhibitor in over 15 CRC CDX or PDX models, SPR2015 showed significantly superior efficacy in the in vivo CRC xenograft models, achieving a 64.7% objective response rate (ORR) and 94.1% disease control rate (DCR) as monotherapy.
“The diligence question is whether those properties survive translation into humans strongly enough to compensate for SPR2015’s later start,” Sreyashi Paul, PhD, business analyst with Lucidquest Ventures, commented on the firm’s website.
Paul cited the 52% confirmed ORR and 93% disease control rate of Revolution Medicines’ zoldonrasib (RMC-9805) in 27 efficacy-evaluable previously treated KRAS G12D NSCLC patients, reported in May, as well as the early human clinical data produced by Verastem’s VS-7375 in the Phase I/II TARGET-D 101 dose escalation and dose expansion trial (NCT07020221). In June, Verastem reported Phase I/II trial (NCT06162221) data showing 93% (13/14) of heavily pretreated (second- to fourth-line) patients with metastatic PDAC who received 900 mg once-daily monotherapy achieved greater than 50% reduction in the tumor marker CA19-9.
In their announcement, Merck and SciBrunch did not disclose a current timeframe for taking SPR2015 into Phase I.
“Validates R&D strength”
“This agreement with Merck not only validates the R&D strength of our platform but also underscores the potential of SPR2015 in addressing longstanding unmet medical needs in oncology,” Hu said in the companies’ statement. “We are excited that Merck, a global leader in oncology, will take SPR2015 forward.”
Merck agreed to pay SciBrunch up to $2.13 billion consisting of $400 million upfront and the remainder in payments tied to achieving development, commercialization, and other milestones across multiple indications.
Merck will record a pre-tax charge of $400 million related to the SciBrunch agreement, or approximately $0.13 per share, to be included in its GAAP and non-GAAP results for the third quarter. The transaction has closed.
“Evidence continues to accumulate for the therapeutic potential of targeting the KRAS pathway, a well-characterized factor in tumor cell growth,” stated George Addona, senior vice president, discovery, preclinical development and translational medicine, Merck Research Laboratories. “This agreement complements and diversifies our expanding pipeline of precision targeted candidates with SPR2015, a potent engineered inhibitor for one of the most prevalent mutant forms of KRAS found in human cancers.”
The deal continues the trend of U.S. and other Western pharmas partnering with Chinese biotechs on drug development—and in Merck’s case, a trend of striving to rebuild its cancer pipeline in hopes of recouping sales that it stands to lose when its anchor drug, the multi-indication cancer immunotherapy Keytruda® (pembrolizumab), loses exclusivity for key U.S. patents in 2028.
Keytruda generated $15.81 billion in Q1–Q2 2026 sales in addition to the $31.641 billion it generated last year. Those figures do not include the $590 million racked up by Keytruda Qlex, a subcutaneous injection form of Keytruda that won FDA approval in September 2025. A consensus of Wall Street analysts has forecast peak annual revenue for Keytruda of approximately $33 billion by 2028.
$70B potential opportunity
However, Merck envisions more than making up for the loss of Keytruda, having foreseen more than $70 billion of potential commercial opportunity by the mid-2030s, Louise Chen, a managing director with Scotiabank, told Reuters.
Founded in 2014, Shanghai-based SciBrunch focuses on small molecule oncology therapeutics based on clinically validated targets and differentiated product design strategies. Hu, a serial entrepreneur, founded SciBrunch with medicinal chemist Yang Zhang, PhD, who is the company’s CSO.
In January, SciBrunch completed an oversubscribed Pre-A round financing of over $35 million, bringing its total capital raised to $65 million over two rounds. Among intended uses for the proceeds, the company announced at the time, was “advancing IND-enabling studies for a new generation of innovative molecular glue RAS inhibitors, exploring their clinical potential in RAS-mutated refractory tumors including colorectal cancer, pancreatic cancer, and non-small cell lung cancer, with the goal of developing preferred therapies for RAS-driven cancers.”
HighLight Capital led the $35 million Pre-A round, with participation from new investor InnoPinnacle Fund and existing shareholders that increased their investments in SciBrunch, including Hankang Capital, BioTrack Capital, LongRiver Investments, and Elikon Venture.
“Since our founding, SciBrunch has remained focused on advancing innovative therapies targeting the RAS pathway and is committed to delivering transformative treatment options for patients with pancreatic, colorectal, lung, and other major malignant tumors,” Hu added.
SPR2015 is not SciBrunch’s lead candidate. That distinction belongs to SPR1020, a brain-penetrant PARP1 selective inhibitor being developed to fight metastatic brain cancer (mBC, with or without brain metastases), ovarian cancer, PDAC, prostate cancer, and glioblastoma. SPR1020 is under study in patients with advanced solid tumors in a Phase I/II open-label, first-in-human trial (NCT07359066) which dosed its first patient on January 8.
“SPR1020 is expected to demonstrate significant efficacy against tumors harboring BRCA mutations or homologous recombination repair (HRR) pathway gene alterations (e.g., breast cancer, prostate cancer),” SciBrunch predicted in the trial’s page on ClinicalTrials,gov.
