Sionna preps dual combo cystic fibrosis attack, salvaging AbbVie assets

Sionna Therapeutics, a Boston-based biotech company, has strategically utilized part of its recent $182 million series C funding by securing a deal with AbbVie. This agreement allows Sionna to integrate three clinical-phase candidates into its growing pipeline focused on cystic fibrosis treatments.

Sionna is positioning itself as a significant competitor to Vertex Pharmaceuticals, which currently dominates the cystic fibrosis market. The company is advancing programs that specifically target the correction of the NBD1 domain, a key component in restoring CFTR function in patients with the most prevalent cystic fibrosis mutation. Sionna believes that combining different treatment modalities may offer the best outcomes for these patients.

On Tuesday, Sionna accelerated its combination treatment strategy by acquiring three molecules from AbbVie. These include two mid-phase compounds: ABBV-2222, a CFTR corrector, and ABBV-3067, a CFTR potentiator. Also known as galicaftor and navocaftor, respectively, these molecules were previously tested by AbbVie in combination with a C1 or C2 inhibitor in a mid-phase clinical trial. Unfortunately, the combinations did not meet AbbVie’s expectations, leading the company to halt the study and subsequently discontinue its cystic fibrosis program. AbbVie had initially expanded its cystic fibrosis efforts by paying Galapagos $45 million upfront in 2018.

In addition to the mid-phase compounds, Sionna has acquired rights to a phase 1 corrector, ABBV-2851. According to Sionna, both ABBV-2222 and ABBV-2851 are designed to correct TMD1, one of the functional domains of the CFTR protein. Sionna’s own pipeline includes a TMD1-directed corrector, SION-676, currently in preclinical development, and an ICL4-targeted candidate, SION-109, which is in phase 1.

This acquisition offers Sionna a variety of choices for advancing its pipeline. The company reported that pairing its NBD1 stabilizers with any of the three newly acquired AbbVie assets or SION-109 demonstrated superior efficacy compared to the current standard of care in cystic fibrosis assays. Sionna plans to prioritize one of these combinations, advancing it in conjunction with its most advanced NBD1 stabilizer.

The deal with AbbVie involved an upfront payment, an equity investment in Sionna, and provisions for AbbVie to receive potential late-stage development and commercial milestones, as well as royalties. However, the financial specifics of the agreement have not been disclosed.