Why Is Breast Cancer-Focused G1 Therapeutics Stock Trading Lower Today?

G1 Therapeutics Inc GTHX shares are trading lower after the company provided an interim update on the Phase 3 PRESERVE 2 trial of trilaciclib as the first-line treatment of metastatic triple-negative breast cancer (mTNBC).

This clinical trial evaluates trilaciclib combined with gemcitabine and carboplatin as a first-line treatment for mTNBC. The independent Data Monitoring Committee (DMC) overseeing the trial has recommended it continue to the final analysis.

In its third quarter 2023 earnings release, G1 said it expected the interim OS analysis to be conducted by its data monitoring committee in the first quarter of 2024. 

If the trial meets the interim analysis stopping rule, it will be unblinded, and G1 will report the top-line results. 

If it does not, the trial will continue to the final analysis, which is expected later in 2024. Investors are probably reacting due to the need to continue the study.

If the results of the interim OS analysis are positive, the company intends to meet with the FDA to discuss filing a supplemental new drug application as soon as possible in 2024, the company said in November.

The DMC did not express any safety concerns or recommend any other changes to the study. G1 remains blinded to all data as the early stopping criteria were not met during the interim analysis.

“While a positive interim analysis would have enabled us to bring this therapy to patients in need sooner, we look forward to completing the study and potentially making this meaningful new treatment option available to patients with this highly aggressive form of breast cancer as early as next year.”

This final analysis evaluating Overall Survival is estimated to occur in the third quarter of 2024 and will be conducted on the intent-to-treat population. 

The company ended the third quarter with cash, cash equivalents, and marketable securities of $94.4 million, which is expected to be sufficient to fund G1’s operations and capital expenditures beyond the third quarter of 2024.

Wedbush maintains the Outperform rating but lowered the price target from $5 to $4.

Needham also maintains G1 Therapeutics with a Buy, lowering the price target from $14 to $12.

Price Action: GTHX shares are down 51.6% at $2.17 on the last check Tuesday.