Phanes secures second FDA orphan status for bispecific antibody

Phanes Therapeutics has achieved a significant regulatory milestone as its bispecific antibody PT217 has been granted orphan drug designation by the U.S. Food and Drug Administration (FDA) for the treatment of neuroendocrine carcinoma (NEC). This designation follows a previous orphan drug status awarded in 2022 for the treatment of small cell lung cancer (SCLC).

Orphan drug designation by the FDA provides several benefits, including tax credits for clinical trials, exemption from user fees, and potential market exclusivity for up to seven years following the approval of the therapy, which exceeds the typical five-year market exclusivity period. These incentives are designed to encourage the development of treatments for rare diseases.

PT217 is a bispecific antibody targeting delta-like ligand 3 (DLL3) and cluster of differentiation 47 (CD47). Phanes Therapeutics is actively investigating PT217 in patients with advanced or refractory cancers that express DLL3, including SCLC, extrapulmonary NECs, and large cell neuroendocrine carcinoma of the lung (LCNEC). The ongoing Phase I SKYBRIDGE trial (NCT05652686) aims to evaluate the safety, tolerability, and pharmacokinetics of PT217 in combination with Roche’s PD-L1 inhibitor Tecentriq (atezolizumab).

The development of bispecific antibodies has garnered significant interest within the pharmaceutical industry. For instance, Merck & Co (MSD) recently announced its intention to acquire a CD3 and CD19-targeting T cell engager bispecific antibody, CN201, from Curon Biopharmaceutical. This acquisition deal is valued at approximately $1.3 billion, encompassing both upfront and milestone-based payments, with the transaction expected to finalize in the third quarter of this year.

Similarly, in May, Johnson & Johnson (J&J) secured global rights for Numab Therapeutics’ bispecific antibody targeting IL-4R and IL-31 for $1.25 billion. This therapy is presently being evaluated for the treatment of atopic dermatitis in a Phase I clinical trial (NCT05859724).

In addition to PT217, Phanes Therapeutics' pipeline includes several other promising candidates. PT199 is a CD73-targeting monoclonal antibody being tested in combination with BeiGene’s Tivimbra (tislelizumab) for solid tumors in the Phase I MORNINGSTAR trial (NCT05431270). Another notable candidate is PT886, a bispecific antibody targeting Claudin 18.2 (CLDN18.2) and CD47. PT886 is currently being evaluated in combination with MSD’s Keytruda (pembrolizumab) in the Phase I/II TWINPEAK study (NCT05482893). This trial aims to enroll approximately 114 participants with unresectable or metastatic gastric adenocarcinoma, gastroesophageal junction (GEJ) adenocarcinoma, and pancreatic ductal adenocarcinoma (PDAC).

The recent advancements and strategic acquisitions in the bispecific antibody space underscore the growing recognition of their potential in addressing complex and unmet medical needs. Phanes Therapeutics, with its diverse pipeline and innovative approaches, continues to make substantial strides in the oncology field, aiming to provide new therapeutic options for patients with challenging cancers.