Physician Views Off-Label Use A 'Double-Edged Sword' For TG Therapeutics

Benjamin noted Farber's practice treats approximately 80 patients per week who suffer from chronic lymphocytic leukemia, of which up to 12 are being treated with TG Therapeutics' ibrutinib.

The doctor also said that among new patients recently diagnosed with CLL, one-third need treatment right away, one-third will likely be treated anywhere from one to 10 years down the road and the remaining one-third don't receive any treatment.

Among the patients who require therapy, Farber does not think there is a mandatory guideline in terms of which regimen needs to be prescribed since every patient is different.

Double-Edged Sword

Farber told the analyst he prefers not to prescribe a patient with an off-label therapy, as this creates a risk of not being reimbursed for an oncology drug.

Benjamin believes Farber's comments are likely shared across the community setting and should be viewed as a "double-edged sword." On one hand, physicians wouldn't "substitute rituximab or Gazyva for TG-1101 if the TG-1101/ibrutinib combination were to be approved in relapsed/refractory high-risk CLL," which is a clear positive for TG Therapeutics. On the other hand, "If the combination is approved in the r/r setting, it is unlikely to be used in the front-line setting unless the company is able to secure a very broad label" — something which is unlikely.

The Winning Combination

Farber indicated that if TG-1101 plus ibrutinib is approved for high-risk CLL patients he would "certainly" give the combination instead of ibrutinib monotherapy given a superior greater overall response rate based on the Phase III GENUINE results.

Finally, Farber argued for his preferences of the combo, especially if it gets a broader label to include all patients, although the analyst believes this is "not likely."