In the phase 3, double-blind, randomized INAVO120 trial, treatment with inavolisib plus palbociclib–fulvestrant led to a significant progression-free survival benefit, as compared with placebo plus palbociclib–fulvestrant, among patients with PIK3CA-mutated, hormone receptor–positive, human epidermal growth factor receptor 2 (HER2)–negative locally advanced or metastatic breast cancer who had had relapse during or within 12 months after completion of adjuvant endocrine therapy.
We randomly assigned patients with PIK3CA-mutated, hormone receptor–positive, HER2-negative locally advanced or metastatic breast cancer who had had disease recurrence or progression during or within 12 months after completion of adjuvant endocrine therapy to receive inavolisib plus palbociclib–fulvestrant (inavolisib group) or placebo plus palbociclib–fulvestrant (placebo group). In the current report, we provide the results of the final analysis of overall survival, including updated data on efficacy and safety. Research Summary Overall Survival with Inavolisib in PIK3CA-Mutated Advanced Breast Cancer
A total of 161 patients were assigned to the inavolisib group, and 164 to the placebo group. After a median follow-up of 34.2 months in the inavolisib group and 32.3 months in the placebo group, the median overall survival was 34.0 months (95% confidence interval [CI], 28.4 to 44.8) with inavolisib and 27.0 months (95% CI, 22.8 to 38.7) with placebo (hazard ratio for death, 0.67; 95% CI, 0.48 to 0.94; P=0.02 [prespecified boundary for statistical significance, P<0.0469]). An objective response occurred in 62.7% (95% CI, 54.8 to 70.2) of patients in the inavolisib group and 28.0% (95% CI, 21.3 to 35.6) of those in the placebo group (P<0.001). The updated hazard ratio for disease progression or death was 0.42 (95% CI, 0.32 to 0.55). Adverse events led to discontinuation of inavolisib in 6.8% of patients and discontinuation of placebo in 0.6%. The incidence of hyperglycemia, stomatitis or mucosal inflammation, gastrointestinal toxic effects (e.g., diarrhea), and ocular toxic effects (e.g., dry eye and blurred vision) was higher with inavolisib than with placebo.
Treatment with inavolisib plus palbociclib–fulvestrant led to a significant overall survival benefit, as compared with placebo plus palbociclib–fulvestrant. Hyperglycemia, stomatitis or mucosal inflammation, gastrointestinal toxic effects, and ocular toxic effects were reported more frequently with inavolisib than with placebo. (Funded by F. Hoffmann–La Roche; INAVO120 ClinicalTrials.gov number, NCT04191499.)
Progression-free survival (PFS) was statistically significantly improved with addition of tucatinib versus placebo 24.9 v 16.3 months regardless of the presence/absence of BM or hormone receptor status.
1467 pts with RS > 25 and 551 with clinically (neoadjuvant cohort in ADAPT-HR+/HER2-) or pathologically N2, (longer) docetaxel-based CTx showed better distant, invasive disease-free survival in N2-3 pts patients with RS ≤25, OS was also shown in pts with RS>25 anthracycline regimens did not show a significant survival difference in high-risk HR+/HER2 whether used in neoadjuvant or adjuvant setting. So may be no anthracycline for HR+ve pts who are high risk disease.
Primary objective not met, ctDNA clearance post- neoadjuvant therapy (NAT) cannot reliably predict pathologic complete response (pCR) and shouldn't be used to defer surgery. But the prognostic data are striking: post-NAT ctDNA positivity independently predicted recurrence in triple-negative breast cancer (TNBC) (HR 8.9), and the postsurgical landmark analysis is essentially binary, 100% of ctDNA-positive patients recurred while 94% of ctDNA-negative patients were disease-free at 5 years (HR 128). Not practice-changing yet pending prospective utility trials, but this strongly validates ultrasensitive ctDNA as a prognostic tool and a smart enrollment biomarker for future escalation/de-escalation trials.
Gedatolisib potently targets all four class I PI3K isoforms and mTORC1 and mTORC2 to comprehensively block the PI3K/AKT/mTOR pathway. PFS was 9.3 m in the gedatolisib-triplet group vs 2.0 m in the fulvestrant group (hazard ratio) HR 0.24, and 7.4 m in the gedatolisib-doublet group HR 0.33 v fulvestrant.
This is impressive. However, there is no reported placebo trastuzumab deruxtecan arm, so this is not truly a “no chemotherapy” regimen. It is important to remember that deruxtecan is itself a chemotherapy agent. So, this is really comparing deruxtecan vs taxol or more accurately, a comparison of chemotherapy delivery systems.