The Oncology Nurse’s Perspective on Recently Reported SOLAR-1 Findings

December 2021 Vol 12, No 12
Jaimie Heldstab, FNP-BC, AOCNP
The University of Kansas Cancer Center, Westwood, KS
Janie A. Metsker, RN, BSN, CN-BN, ONN-CG
Saint Luke’s Breast Center and Saint Luke’s Koontz Center for Advanced Breast Cancer, Kansas City, MO

Background: PIK3CA, the gene encoding the α-subunit of phosphatidylinositol-3-kinase (PI3Kα), is mutated in ~40% of hormone receptor–positive (HR+), HER2– advanced breast cancer (ABC) tumors. These mutations can drive malignant transformation and are a negative prognostic factor in these patients. Alpelisib, an α-selective PI3K inhibitor and degrader, plus fulvestrant is approved for PIK3CA-mutated, HR+, HER2– ABC based on the phase 3 SOLAR-1 trial (NCT02437318). For patients with PIK3CA-mutated disease, alpelisib plus fulvestrant compared with placebo plus fulvestrant improved progression-free survival (hazard ratio, 0.65, median 11.0 months vs 5.7 months) and had a tolerable safety profile. Hyperglycemia and rash, which are considered on-target effects of PI3K inhibitors, were frequently observed.

Objective: To provide an oncology nurse’s perspective on recent SOLAR-1 findings that may affect the care of alpelisib-treated patients. The rationale is that more detailed adverse event (AE) management guidelines have been shown to improve alpelisib safety outcomes.1

Methods: A qualitative analysis of SOLAR-1 data of potential interest to oncology nurses presented at congresses between July 1, 2020, and July 10, 2021, was performed.

Results: Overall, PI3K inhibitor–associated hyperglycemia management continues to be a highly active area of investigation. In a recent ad hoc analysis, a risk factor model identified baseline fasting plasma glucose, body mass index (BMI), glycosylated hemoglobin, monocyte count, and age as top predictors for developing grade 3/4 hyperglycemia.2 When applied to SOLAR-1, this model showed that ~90% of the 106 patients classified as “high risk” developed grade 3/4 hyperglycemia (vs 7% of the 178 low-risk patients). Notably, most (86%) high-risk patients remained on alpelisib treatment. Another study showed that 6 SOLAR-1 patients who received sodium-glucose cotransporter-2 inhibitors with other antihyperglycemia agents were able to stay on alpelisib treatment despite having ≥1 baseline risk factors for this AE (prediabetic/diabetic status, BMI ≥30, or age ≥75 years) and had longer duration of alpelisib treatment versus all patients.3 Another analysis showed that, for patients with grade 1/2 hyperglycemia, delayed intervention with antihyperglycemia medication (44 patients) resulted in a higher chance of hyperglycemia not improving or worsening versus early intervention (22 patients).4 Finally, an analysis of long-term disease control (progression-free survival ≥18 months, which was achieved by 30% of alpelisib-treated patients) showed that diabetes/prediabetes at baseline, as well as poor prognosis and heavy pretreatment, do not preclude long-term benefit from this combination.5

Conclusions: From the nursing perspective, results from these studies reinforce our observations that alpelisib-associated hyperglycemia can be effectively managed with early detection and intervention. Notably, this also appears to be true for patients with baseline risk factors such as high blood glucose and high BMI. Ultimately, the goal of AE management is to keep patients on therapy for as long as possible to help delay disease progression. In our experience, patient education before alpelisib initiation and follow-up is also critical for optimal control and prevention of hyperglycemia. Further studies are needed on potential barriers to monitoring and managing hyperglycemia, such as insurance coverage for proactive use of medication and at-home monitoring devices.


  1. Rugo HS, André F, Yamashitaet T, et al. Time course and management of key adverse events during the randomized phase III SOLAR-1 study of PI3K inhibitor alpelisib plus fulvestrant in patients with HR-positive advanced breast cancer. Ann Oncol. 2020;31:1001-1010.
  2. Rodon J, Demanse D, Rugo HS, et al. A risk analysis of alpelisib (ALP)-induced hyperglycemia (HG) using baseline factors in patients (pts) with advanced solid tumors and breast cancer (BC): a pooled analysis of X2101 and SOLAR-1. ESMO 2021. Abstract 96MO.
  3. Lu Y-S, Chiu J, Airoldi M, et al. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors for alpelisib (ALP)-induced hyperglycemia: a report of 6 cases from SOLAR-1. ESMO 2020. Abstract 301P.
  4. Mayer I, Farooki A, Rugo HS, et al. Early intervention for and management of alpelisib (ALP)-induced hyperglycemia: case studies from the phase III SOLAR-1 trial. SABCS 2020. Abstract PS10-35.
  5. Juric D, Andre F, Panwaret U, et al. Long-term (LT) disease control in patients (pts) with hormone receptor–positive (HR+), PIK3CA-altered advanced breast cancer (ABC) treated with alpelisib (ALP) + fulvestrant (FUL). ASCO 2021. Poster 1054.
Related Articles
Assessment of Side Effects (SEs) Impacting Quality of Life (QOL) in Patients (Pts) Undergoing Treatment (tx) for Advanced Breast Cancer (ABC) in Clinical Practice: A Real-World (RW) Multicountry Survey
November 2022 Vol 13, No 11
To examine how SEs impacting QOL in pts with ABC are perceived.
Intracranial Activity of Tepotinib in Patients with MET Exon 14 (METex14) Skipping Non–Small-Cell Lung Cancer (NSCLC) Enrolled in VISION
November 2022 Vol 13, No 11
To provide analysis of the intracranial activity of tepotinib in patients with METex14 skipping NSCLC with BM from the VISION study to aid oncology nurse navigators who manage this population of patients.
MOMENTUM: Phase 3 Randomized Study of Momelotinib (MMB) versus Danazol (DAN) in Symptomatic and Anemic Myelofibrosis (MF) Patients Previously Treated with a JAK Inhibitor
November 2022 Vol 13, No 11
MF is a rare bone marrow cancer characterized by fibrosis, abnormal blood cell production, and dysregulated JAK/STAT signaling.1,2
Last modified: August 10, 2023

Subscribe Today!

To sign up for our print publication or e-newsletter, please enter your contact information below.

I'd like to receive:

  • First Name *
    Last Name *
    Profession or Role
    Primary Specialty or Disease State