FDA Approval Summary: Alpelisib Plus Fulvestrant for Patients with HR-positive, HER2-negative, PIK3CA-mutated, Advanced or Metastatic Breast Cancer.

On May 24, 2019, the FDA granted regular approval to alpelisib in combination with fulvestrant for postmenopausal women, and men, with hormone receptor (HR)-positive, HER2-negative, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-mutated, advanced or metastatic breast cancer as detected by an FDA-approved test following progression on or after an endocrine-based regimen. Approval was based on the SOLAR-1 study, a randomized, double-blind, placebo-controlled trial of alpelisib plus fulvestrant versus placebo plus fulvestrant. The primary endpoint was investigator-assessed progression-free survival (PFS) per RECIST v1.1 in the cohort of trial participants whose tumors had a PIK3CA mutation. The estimated median PFS by investigator assessment in the alpelisib plus fulvestrant arm was 11 months [95% confidence interval (CI), 7.5-14.5] compared with 5.7 months (95% CI, 3.7-7.4) in the placebo plus fulvestrant arm (HR, 0.65; 95% CI, 0.50-0.85; two-sided P = 0.001). The median overall survival was not yet reached for the alpelisib plus fulvestrant arm (95% CI, 28.1-NE) and was 26.9 months (95% CI, 21.9-NE) for the fulvestrant control arm. No PFS benefit was observed in trial participants whose tumors did not have a PIK3CA mutation (HR, 0.85; 95% CI, 0.58-1.25). The most common adverse reactions, including laboratory abnormalities, on the alpelisib plus fulvestrant arm were increased glucose, increased creatinine, diarrhea, rash, decreased lymphocyte count, increased gamma glutamyl transferase, nausea, increased alanine aminotransferase, fatigue, decreased hemoglobin, increased lipase, decreased appetite, stomatitis, vomiting, decreased weight, decreased calcium, decreased glucose, prolonged activated partial thromboplastin time, and alopecia.

Narayan P ，Prowell TM ，Gao JJ ，Fernandes LL ，Li E ，Jiang X ，Qiu J ，Fan J ，Song P ，Yu J ，Zhang X ，King-Kallimanis BL ，Chen W ，Ricks TK ，Gong Y ，Wang X ，Windsor K ，Rhieu SY ，Geiser G ，Banerjee A ，Chen X ，Reyes Turcu F ，Chatterjee DK ，Pathak A ，Seidman J ，Ghosh S ，Philip R ，Goldberg KB ，Kluetz PG ，Tang S ，Amiri-Kordestani L ，Theoret MR ，Pazdur R ，Beaver JA ... -  《-》

Alpelisib Plus Fulvestrant in PIK3CA-Altered and PIK3CA-Wild-Type Estrogen Receptor-Positive Advanced Breast Cancer: A Phase 1b Clinical Trial.

Juric D ，Janku F ，Rodón J ，Burris HA ，Mayer IA ，Schuler M ，Seggewiss-Bernhardt R ，Gil-Martin M ，Middleton MR ，Baselga J ，Bootle D ，Demanse D ，Blumenstein L ，Schumacher K ，Huang A ，Quadt C ，Rugo HS ... -  《-》

Alpelisib for PIK3CA-Mutated, Hormone Receptor-Positive Advanced Breast Cancer.

PIK3CA mutations occur in approximately 40% of patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. The PI3Kα-specific inhibitor alpelisib has shown antitumor activity in early studies. In a randomized, phase 3 trial, we compared alpelisib (at a dose of 300 mg per day) plus fulvestrant (at a dose of 500 mg every 28 days and once on day 15) with placebo plus fulvestrant in patients with HR-positive, HER2-negative advanced breast cancer who had received endocrine therapy previously. Patients were enrolled into two cohorts on the basis of tumor-tissue PIK3CA mutation status. The primary end point was progression-free survival, as assessed by the investigator, in the cohort with PIK3CA-mutated cancer; progression-free survival was also analyzed in the cohort without PIK3CA-mutated cancer. Secondary end points included overall response and safety. A total of 572 patients underwent randomization, including 341 patients with confirmed tumor-tissue PIK3CA mutations. In the cohort of patients with PIK3CA-mutated cancer, progression-free survival at a median follow-up of 20 months was 11.0 months (95% confidence interval [CI], 7.5 to 14.5) in the alpelisib-fulvestrant group, as compared with 5.7 months (95% CI, 3.7 to 7.4) in the placebo-fulvestrant group (hazard ratio for progression or death, 0.65; 95% CI, 0.50 to 0.85; P<0.001); in the cohort without PIK3CA-mutated cancer, the hazard ratio was 0.85 (95% CI, 0.58 to 1.25; posterior probability of hazard ratio <1.00, 79.4%). Overall response among all the patients in the cohort without PIK3CA-mutated cancer was greater with alpelisib-fulvestrant than with placebo-fulvestrant (26.6% vs. 12.8%); among patients with measurable disease in this cohort, the percentages were 35.7% and 16.2%, respectively. In the overall population, the most frequent adverse events of grade 3 or 4 were hyperglycemia (36.6% in the alpelisib-fulvestrant group vs. 0.7% in the placebo-fulvestrant group) and rash (9.9% vs. 0.3%). Diarrhea of grade 3 occurred in 6.7% of patients in the alpelisib-fulvestrant group, as compared with 0.3% of those in the placebo-fulvestrant group; no diarrhea of grade 4 was reported. The percentages of patients who discontinued alpelisib and placebo owing to adverse events were 25.0% and 4.2%, respectively. Treatment with alpelisib-fulvestrant prolonged progression-free survival among patients with PIK3CA-mutated, HR-positive, HER2-negative advanced breast cancer who had received endocrine therapy previously. (Funded by Novartis Pharmaceuticals; SOLAR-1 ClinicalTrials.gov number, NCT02437318.).

André F ，Ciruelos E ，Rubovszky G ，Campone M ，Loibl S ，Rugo HS ，Iwata H ，Conte P ，Mayer IA ，Kaufman B ，Yamashita T ，Lu YS ，Inoue K ，Takahashi M ，Pápai Z ，Longin AS ，Mills D ，Wilke C ，Hirawat S ，Juric D ，SOLAR-1 Study Group ... -  《-》

Alpelisib plus fulvestrant for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: final overall survival results from SOLAR-1.

Activation of the phosphatidylinositol-3-kinase (PI3K) pathway via PIK3CA mutations occurs in 28%-46% of hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancers (ABCs) and is associated with poor prognosis. The SOLAR-1 trial showed that the addition of alpelisib to fulvestrant treatment provided statistically significant and clinically meaningful progression-free survival (PFS) benefit in PIK3CA-mutated, HR+, HER2- ABC. Men and postmenopausal women with HR+, HER2- ABC whose disease progressed on or after aromatase inhibitor (AI) were randomized 1 : 1 to receive alpelisib (300 mg/day) plus fulvestrant (500 mg every 28 days and once on day 15) or placebo plus fulvestrant. Overall survival (OS) in the PIK3CA-mutant cohort was evaluated by Kaplan-Meier methodology and a one-sided stratified log-rank test was carried out with an O'Brien-Fleming efficacy boundary of P ≤ 0.0161. In the PIK3CA-mutated cohort (n = 341), median OS [95% confidence interval (CI)] was 39.3 months (34.1-44.9) for alpelisib-fulvestrant and 31.4 months (26.8-41.3) for placebo-fulvestrant [hazard ratio (HR) = 0.86 (95% CI, 0.64-1.15; P = 0.15)]. OS results did not cross the prespecified efficacy boundary. Median OS (95% CI) in patients with lung and/or liver metastases was 37.2 months (28.7-43.6) and 22.8 months (19.0-26.8) in the alpelisib-fulvestrant and placebo-fulvestrant arms, respectively [HR = 0.68 (0.46-1.00)]. Median times to chemotherapy (95% CI) for the alpelisib-fulvestrant and placebo-fulvestrant arms were 23.3 months (15.2-28.4) and 14.8 months (10.5-22.6), respectively [HR = 0.72 (0.54-0.95)]. No new safety signals were observed with longer follow-up. Although the analysis did not cross the prespecified boundary for statistical significance, there was a 7.9-month numeric improvement in median OS when alpelisib was added to fulvestrant treatment of patients with PIK3CA-mutated, HR+, HER2- ABC. Overall, these results further support the statistically significant prolongation of PFS observed with alpelisib plus fulvestrant in this population, which has a poor prognosis due to a PIK3CA mutation. CLINICALTRIALS. NCT02437318.

André F ，Ciruelos EM ，Juric D ，Loibl S ，Campone M ，Mayer IA ，Rubovszky G ，Yamashita T ，Kaufman B ，Lu YS ，Inoue K ，Pápai Z ，Takahashi M ，Ghaznawi F ，Mills D ，Kaper M ，Miller M ，Conte PF ，Iwata H ，Rugo HS ... -  《-》

Patient-Reported Outcomes in Patients With PIK3CA-Mutated Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer From SOLAR-1.

Ciruelos EM ，Rugo HS ，Mayer IA ，Levy C ，Forget F ，Delgado Mingorance JI ，Safra T ，Masuda N ，Park YH ，Juric D ，Conte P ，Campone M ，Loibl S ，Iwata H ，Zhou X ，Park J ，Ridolfi A ，Lorenzo I ，André F ... -  《-》