Shares of G1 Therapeutics Inc ( GTHX ) are trading lower after the company released topline results from the final OS analysis of its Phase 3 PRESERVE 2 trial evaluating the efficacy and safety of trilaciclib administered before chemotherapy (gemcitabine and carboplatin; GCb) for metastatic Metastatic Triple Negative Breast Cancer (TNBC).

In February, G1 Therapeutics ( GTHX ) shared an interim update on the Phase 3 PRESERVE 2 trial of trilaciclib.

The study did not demonstrate a statistically significant treatment effect in the Intent-to-Treat  (ITT) population (n=187) with a hazard ratio (HR) of 0.91 (p=0.884).

The median overall survival (OS) in the trilaciclib plus GCb arm was 17.4 months compared to 17.8 months in the control arm.

Median OS numerically favored the trilaciclib arm in both PD-L1 subgroups (positive and negative), though neither achieved statistical significance.

Varying effects were observed across regions and patients who received different types of subsequent therapies.

The safety profile of trilaciclib with GCb observed in the trial was consistent with prior studies, and no new safety signals were identified.

Consistent with other trilaciclib studies, evidence of myeloprotection was observed, including a reduction in the occurrence of severe neutropenia, which occurred in 8% of patients who received trilaciclib compared to 29% of patients in the control arm.

Jack Bailey, CEO said, “We will now further our focus on both accelerating and expanding the growth of the ES-SCLC business to achieve anticipated company profitability in the second half of 2025 and evaluating other myeloprotection uses for trilaciclib. We are also pursuing ex-US partners to expand the use of COSELA (trilaciclib) globally.”

G1 today reaffirmed its full-year 2024 COSELA net revenue guidance and updated its cash runway guidance.

The company expects to generate between $60 million and $70 million in COSELA net revenue in 2024.

Additionally, G1 plans to wind down the Phase 3 PRESERVE 2 trial, discontinue the anticipated hiring of staff and investment for a 1L TNBC indication, and make targeted headcount reductions outside of the existing commercial organization to streamline the company.

These efforts are expected to provide sufficient cash runway to achieve anticipated company profitability in the second half of 2025.

Price Action: GTHX shares are down 33.1% at $1.66 at last check Monday.