Roche celebrates Pharma Day by buying Regor's CDK inhibitors, regenerative med-focused AntlerA

Genentech is paying $850 million upfront for Regor Pharmaceuticals’ portfolio of CDK inhibitors, taking ownership of a breast cancer candidate that has shown signs of single-agent efficacy in patients failed by existing options. 

The deal was announced on Roche's Pharma Day, where the Swiss Big Pharma—which owns Genentech—also disclosed (PDF) the acquisition of Wnt signaling-focused biotech AntlerA Therapeutics.

Regor, a Chinese-American biotech, presented phase 1a results on its next-generation CDK inhibitor late last year. The biotech designed the drug candidate to have high potency against CDK4, additional activity versus CDK2 and selectivity against CDK6. Those features are intended to overcome resistance to CDK4/6 inhibition and reduce hematologic toxicity.

The biotech is testing the molecule, which is called RGT-419B, in hormone receptor (HR)-positive, HER2-negative advanced or metastatic breast cancer patients who progressed on prior CDK4/6 inhibitors. All 12 of the women in the analysis had previously received Pfizer’s CDK4/6 inhibitor Ibrance. Two patients had also taken Novartis’ Kisqali or Eli Lilly’s Verzenio, other approved CDK inhibitors.

Regor saw (PDF) two confirmed and one unconfirmed partial responses during dose escalation. The monotherapy’s 28.6% confirmed partial response rate in seven patients with measurable disease, plus absence of grade 3 or higher adverse events, led Regor to plan dose expansions of RGT-419B as a single agent and in combination with endocrine therapy.

The biotech will manage two ongoing phase 1 trials of RGT-419B to completion. After that, Genentech will be responsible for clinical development, manufacturing and commercialization worldwide. As the CDK inhibitors advance, Genentech could pay development, regulatory and commercial milestones of undisclosed size.

Buying RGT-419B continues Roche’s push into HR-positive breast cancer, which represents around 70% of all cases. The Swiss drugmaker is developing giredestrant, a selective endocrine receptor degrader, and inavolisib, a PI3K inhibitor, in HR-positive disease. Roche sees giredestrant as a potential replacement for endocrine therapies that combines tolerably with CDK inhibitors. The ability to combine inavolisib with CDK inhibitors is central to Roche’s attempt to differentiate the PI3K inhibitor.

To date, Roche has paired its candidates with CDK inhibitors from Lilly, Novartis and Pfizer. Genentech’s acquisition of the Regor portfolio, which is expected to close in the fourth quarter, will give Roche its own CDK inhibitors.

After selling the CDK inhibitor portfolio, Regor will focus on its remaining oncology, metabolic disease and autoimmune assets. The pipeline is led by an oral GLP-1 receptor agonist that is in clinical development in diabetes and obesity. Lilly partnered with the biotech to work on metabolic disorders in 2021. 

Meanwhile, the acquisition of AntlerA, which Roche called a leader in Wnt signaling, gives the pharma ownership of a library of anti-FZD/LRP drug candidates. Roche sees AntlerA’s preclinical lead asset as a potential best-in-class treatment for neovascular age-related macular degeneration and diabetic macular edema.

Roche wouldn't disclose the financial details of the deal, but a spokesperson told Fierce Biotech that the biotech's pipeline is “a strong fit with our interest in ophthalmology and ... the Wnt pathway could be very promising for the treatment of other diseases.”

Today's oncology and eye-focused deals strengthen Roche’s pipeline in two of the five priority areas for its new pharma strategy, which the company reaffirmed at its Pharma Day in London this morning. Roche’s 10-year ambition is to deliver 20 transformative medicines addressing diseases with the highest societal burden, executives explained to attendees at the event.