New targeted therapies for relapsed or refractory mantle cell lymphoma

This study reviewed current and new targeted therapies for relapsed or refractory (does not respond to treatment) mantle cell lymphoma.

Ibrutinib (Imbruvica) remains the current standard of care for patients with mantle cell lymphoma (MCL) who relapse or develop refractory disease after initial therapy.

Ibrutinib is a targeted therapy. This type of treatment only targets cancer cells, and blocks their growth. This leads to cancer cell death. However, 33% of patients do not achieve long-term remission with ibrutinib. New targeted therapies remain under investigation.

Acalabrutinib (Calquence) and tirabrutinib are new therapies similar to ibrutinib with fewer side effects. In a study with 12 patients, 92% responded to tirabrutinib. Research comparing these therapies to ibrutinib is ongoing.

Idelalisib (Zydelig) and copanlisib (Aliqopa) block cancer cell division. In a study with 40 patients, 40% of patients responded to idelalisib. However, progression-free survival (PFS; time from treatment until disease progression) was 3.7 months. In another study with 11 patients, 63.6% responded to copanlisib.

Bortezomib (Velcade) disrupts cancer cell function. This blocks cancer cell growth and survival. In a study with 141 patients with relapsed or refractory disease, 33% responded to bortezomib. The average overall survival (OS; time from treatment until death from any cause) was 23.5 months.

Lenalidomide (Revlimid) helps the body’s immune system attack cancer cells. In a study with 134 patients who did not respond to bortezomib, 28% responded to lenalidomide. The average PFS was 4.0 months. In another study with 40 patients who did not respond to ibrutinib, 27% responded to lenalidomide.

Temsirolimus (Torisel) blocks cancer cell growth. In a study with 26 patients, 92% responded to temsirolimus combined with bendamustine (Treanda) and rituximab (Rituxan). The average PFS was 33 months. The average OS was 3.55 years.

Venetoclax (Venclexta) is a new therapy that blocks cancer cell survival. In a study with 28 MCL patients, 75% responded to treatment. 21% had disappearance of all signs of cancer. The average PFS was 14 months. 1-year OS was 82%. 11% of all patients (106) reported severe to life-threatening low white blood cell count. 2.83% experienced tumor lysis syndrome (a toxic side effect of dead cancer cells) that was successfully treated.

Combinations of ibrutinib with other targeted therapies remain under investigation in clinical trials.

This study reviewed current and new targeted therapies for relapsed or refractory mantle cell lymphoma.