TIDAL: a phase 2 study of a new drug called zandelisib in people with relapsed or refractory follicular lymphoma

This trial is testing a new targeted drug in people with follicular lymphoma or marginal zone lymphoma that has come back or has not responded to at least two previous courses of treatment.

Note that this trial is no longer recruiting people with follicular lymphoma.

Purpose of trial

The aim of this trial is to find out whether zandelisib is safe and effective in treating people with follicular lymphoma or marginal zone lymphoma (nodal marginal zone lymphoma, extranodal marginal zone lymphoma or splenic marginal zone lymphoma) that has come back (relapsed) or didn’t respond (refractory) to previous treatment.


Zandelisib (previously called ME-401) is a cell-signal blocker that targets a protein called P13K. P13K plays an important role in the growth and survival of B lymphocytes (the type of white blood cells that become abnormal in B-cell lymphomas). Blocking PI3K can stop lymphoma cells dividing or cause them to die.

Everybody in this trial has zandelisib every day for two cycles (56 days). After this, you are randomly put into one of two groups:

  • Group A takes zandelisib as a capsule every day for each 28 day cycle.
  • Group B takes zandelisib as a capsule every day for 7 days followed by 21 days of placebo for the remaining 28 days of each cycle.

You can’t choose which group you are in and neither can your doctor. You are told which group you are in and given information about how you take the medicine. You carry on taking the medicine unless your lymphoma gets worse or you get troublesome side effects.

Who can enter

Your consultant can give you advice on whether you might be suitable for this trial.

Around 180 people are needed for this trial.

You may be able to enter if:

  • You have follicular lymphoma or marginal zone lymphoma. Note that this trial is no longer recruiting people with follicular lymphoma.
  • Your lymphoma is stage 1, 2 or 3a.
  • You have previously had at least two courses of treatment for your lymphoma, including antibody therapy that targets the CD20 antibody (for example, rituximab or obinutuzumab) and chemotherapy with certain drugs. Your doctor can tell you if this is the case.
  • Your lymphoma is measurable by the tests used in the trial.
  • Your blood and other health test results are satisfactory.
  • Your liver, kidneys and heart are healthy enough to take part in the trial.
  • You and your partner are willing to use reliable contraception if there is any chance of you or your partner becoming pregnant.
  • You are 18 or over.

You won't be able to enter if:

  • Your lymphoma has changed (transformed) into a faster-growing (high-grade) type.
  • You have ever had lung inflammation caused by drug treatments.
  • You have a serious heart condition, illness affecting your digestive system or any other illness that is not controlled with treatment.
  • You have hepatitis B.
  • You are pregnant or breastfeeding.
  • Any of the study drugs are not suitable for you.

Further information

More information about this trial is available at clinicaltrials.gov/ct2/show/study/NCT03768505.