TwoStep Therapeutics launched on Tuesday with $6.5 million in seed funding and a stellar crew of co-founders, including renowned protein expert and Nobel Laureate Carolyn Bertozzi, to develop targeted cytotoxic drugs and immunotherapies to treat solid cancers.The seed funding was led by NFX with participation from 2048 Ventures, Alexandria Venture Investments, GC&H Investments, and the family office of the founder of Arcadia Investment Partners. It’s the second Bertozzi-backed biotech to emerge this year. Degrader-antibody conjugate (DAC) developer Firefly Bio debuted with $94 million in February. TwoStep’s other co-founders also hail from Stanford: Jennifer Cochran is a bioengineering professor and the senior associate vice provost for research, and Ronald Levy serves as a professor of medicine and oncology. CEO Caitlyn Miller’s postdoc advisors were Cochran and Bertozzi before she joined the Stanford Innovative Medicines Accelerator (IMA) entrepreneur-in-residence programme, from which TwoStep is the first company to emerge. Altogether, the founding team boasts expertise in chemical biology, antibody-drug conjugates (ADCs), and immuno-oncology.Targeted deliveryTwoStep’s goal is to solve an extracellular target scarcity problem that is often seen with solid tumours. The start-up is developing polyspecific integrin-binding peptide (PIP) molecules that can selectively bind several targets for effective therapeutic delivery, overcoming the limitations of single-antigen directed-treatments. Ultimately, the company aims to “viably treat the majority of solid tumours.”“In its compact form, PIP is a synthetic, ultra-stable peptide that has been engineered to localise and penetrate tumours – ideal properties for broad targeted therapy applications,” said Cochran, whose laboratory first developed the PIP molecule.According to the company, its PIPs can enable targeted delivery to virtually any solid tumour due to its ability to bind with multiple integrins, and in particular specific conformations that are highly expressed on cancers, thereby avoiding healthy tissues. The tumour-targeting technology is modality-agnostic and can be paired with diverse, “clinically-validated payloads, which has the potential to extend the benefits of paradigm-shifting therapies to a greater number of patients,” said Miller.TwoStep’s team has generated in vivo data supporting the use of its PIPs with various therapeutic payloads and fusion proteins.