The effectiveness of monotherapy with PI3K/AKT/mTOR pathway inhibitors in ovarian cancer: A meta-analysis

Gynecol Oncol. 2021 Nov;163(2):433-444. doi: 10.1016/j.ygyno.2021.07.008. Epub 2021 Jul 10.

Abstract

Objective: To determine the clinical benefit of monotherapy with PI3K/AKT/mTOR inhibitors in patients diagnosed with advanced or recurrent ovarian cancer and to investigate the predictive value of current PI3K/AKT/mTOR biomarkers on therapy response.

Methods: A systematic search was conducted in PubMed, Embase and the Cochrane Library for articles reporting on treatment with PI3K/AKT/mTOR inhibitors in ovarian cancer. The primary endpoint was defined as the clinical benefit rate (CBR), including the proportion of patients with complete (CR) and partial response (PR) and stable disease (SD). Secondary endpoints included the overall response rate (ORR, including CR and PR) and drug-related grade 3 and 4 adverse events.

Results: We included 233 patients from 19 studies and observed a pooled CBR of 32% (95% CI 20-44%) and ORR of 3% (95% CI 0-6%) in advanced or recurrent ovarian cancer patients treated with PI3K/AKT/mTOR inhibitors. Subgroup analysis tended to favor the studies who selected patients based on current PI3K/AKT/mTOR biomarker criteria (e.g. genomic alterations or loss of PTEN protein expression), but the difference in CBR was not statistically significant from studies with unselected populations (respectively, CBR of 42% (95% CI 23-62%) and 27% (95% CI 14-42%), P = 0.217). To better reflect true patient benefit, we excluded SD <6 months as a beneficial outcome which resulted in a pooled CBR of 7% (95% CI 2-13%). The overall proportion of patients with drug-related grade 3 and 4 adverse events was 36%.

Conclusions: The efficacy of monotherapy with PI3K/AKT/mTOR inhibitors in advanced recurrent ovarian cancer patients is limited to a small subgroup and selection of patients with the use of current biomarkers did not improved the CBR significantly. Given the toxicity profile, we suggest that current treatment with PI3K/AKT/mTOR inhibitors should not be initiated unless in clinical trials. Furthermore, improved biomarkers to measure functional PI3K/AKT/mTOR pathway activity are needed to optimize patient selection.

Keywords: Akt; Mammalian target of rapamycin; Ovarian cancer; Phosphatidylinositol-3-kinase; Signal transduction pathway; Targeted therapy.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / antagonists & inhibitors
  • Biomarkers, Tumor / metabolism
  • Clinical Decision-Making
  • Female
  • Humans
  • MTOR Inhibitors / administration & dosage*
  • MTOR Inhibitors / adverse effects
  • Neoplasm Staging
  • Ovarian Neoplasms / diagnosis
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / mortality
  • Patient Selection
  • Phosphatidylinositol 3-Kinases / analysis
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors / administration & dosage*
  • Phosphoinositide-3 Kinase Inhibitors / adverse effects
  • Predictive Value of Tests
  • Proto-Oncogene Proteins c-akt / analysis
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / analysis
  • TOR Serine-Threonine Kinases / antagonists & inhibitors
  • TOR Serine-Threonine Kinases / metabolism
  • Treatment Outcome

Substances

  • Antineoplastic Agents
  • Biomarkers, Tumor
  • MTOR Inhibitors
  • Phosphoinositide-3 Kinase Inhibitors
  • MTOR protein, human
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases