ProPhase Labs, Inc. provided an update regarding its progress and development strategy for Linebacker-1 (LB-1), a small molecule PIM kinase inhibitor that is being developed by the Company's wholly owned subsidiary, ProPhase BioPharma, Inc., as a potential therapy enhancer for traditional chemotherapeutic agents to both increase efficacy and decrease toxicity in current cancer treatments. In January 2023, REPROCELL completed its independent review of Linebacker-1, which included testing of 25 cell lines with LB-1 and confirmed previous in vitro studies conducted by Charles River. These cell lines confirmed efficacy of LB-1 on ovarian, kidney, colon and lung adenocarcinoma/small cells.

The two-year research collaboration for Linebacker-1 with Dana-Farber Cancer Institute and Harvard Medical School (which was announced in the third quarter of last year) has officially commenced, with cell culture studies currently ongoing. The ongoing studies are focused on identifying the most effective combination of cancer cell lines and agents with LB-1. Initial focus areas include hepatic, colon and breast cancer, and initial therapy agents include Topotecan and Doxorubicin. Initial results from these cell culture studies are very promising.

Additionally, selection has been confirmed for animal studies; Dana-Farber/Harvard will deploy two animal xenograft models, with and without radiation. The goal for completion of the animal studies is the end of second quarter 2023, with data expected to be published in third quarter 2023. Initial GMP manufacturing for LB-1 is expected to kick off in the third quarter of 2023, in tandem with toxicology studies.

ProPhase expects to initiate the preclinical requirements for investigational new drug (IND) application submission in the fourth quarter of 2023. These requirements include: Study Protocol Design: select optimized co-therapy combo from animal study and complete the protocol design for IND submission Toxicity Testing: toxicological studies on small animals according to study protocol Dosing Studies: dosing studies on small animals according to study protocol Large Animal Studies: combined therapy studies on large animals according to study protocol ProPhase aims to submit its IND application for Linebacker-1 in mid-2024. The Company plans to operate its own Phase 1 safety study for LB-1 and will seek a strategic partner for future development following Phase 1. The Company estimates that the total cost for development prior to exploring a strategic partner will be $3 - $5 million.