SGO 2019: TWiST Backs Benefits of PARP Inhibitor in Ovarian Cancer

March 21, 2019

The TWiST analysis of the phase III ENGOT-OV16/NOVA trial evaluated the time without symptoms or toxicity for niraparib vs placebo in patients with recurrent ovarian cancer.

As a maintenance therapy, niraparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, prolonged the time without symptoms or toxicity (TWiST) for patients with recurrent ovarian cancer compared with placebo, regardless of germline BRCA status. The results of the TWiST analysis of the ENGOT-OV16/NOVA trial were presented at the 2019 Society of Gynecologic Oncology (SGO) 50th Annual Meeting on Women’s Cancer, held March 16–19 in Honolulu, Hawaii.

“When patients with recurrent ovarian cancer enter into a remission following platinum-based treatment, they now have the option to prolong their progression-free survival with a PARP inhibitor,” said Ursula A. Matulonis, MD, presenting author and the director and chief of Gynecologic Oncology at Dana-Farber Cancer Institute, in a press release.

The ENGOT-OV16/NOVA study previously showed that women with recurrent ovarian cancer who received niraparib following platinum-based treatment went longer without disease progression compared with placebo. Matulonis said, “It’s really important to demonstrate that, if we’re adding a maintenance therapy, we’re not significantly altering women’s quality of life.”

The TWiST analysis was based on data from 553 patients from the phase III NOVA trial and calculated using mean progression-free survival (PFS) and mean time with toxicity. For each maintenance treatment arm (niraparib and placebo), mean PFS and mean time with toxicity were estimated, and the difference between treatment arms for mean PFS and mean time with toxicity were used to calculate TWiST.

The symptomatic adverse events captured in the TWiST analysis were grade 2 or higher fatigue, nausea, and vomiting. The total number of days a patients had an adverse event after randomization but before disease progression was defined as toxicity time. TWiST assessments were reported for patients with a germline BRCA mutation and for those without a germline BRCA mutation.

Overall, patients who received maintenance therapy with niraparib experienced longer time without disease progression and longer time without having impactful toxicity, as measured by grade 2 events of fatigue, nausea, or vomiting.

For patients with a germline BRCA mutation, maintenance therapy with niraparib led to a mean PFS benefit of 3.23 years, a mean toxicity time of 0.28 years, and overall TWiST benefit of 2.95 years compared with placebo. For patients without a germline BRCA mutation, maintenance therapy with niraparib led to a mean PFS benefit of 1.44 years, a mean toxicity time of 0.10 years, and overall TWiST benefit of 1.34 years compared with placebo.

“The TWiST data gives us insight into not only the amount of time this drug provided but also the quality of this time. When you are looking at a maintenance drug, qualitative data is extremely important,” said Stephanie Blank, MD, director of the Division of Gynecologic Oncology for the Mount Sinai Health System, during an interview with Cancer Network. However, she cautioned, “The TWiST data looks at three symptoms-fatigue, nausea, and vomiting-and these cannot capture the complete picture of how a woman with ovarian cancer is living.”

“It is wonderful that the investigator looked at this,” Blank added. “It is really important that these type[s] of data be included when defining outcomes.”