PKB171 Against Placebo in Couples With Mild Male Factor Infertility

The test medication Gel PKB171 is a vaginal gel that has not yet been licensed by the regulatory authorities. However, the active substance pentoxifylline has been available as tablets for decades and is used to increase peripheral blood flow in patients with circulation problems. Additionally, pentoxifylline is used to treat sperm samples in artificial insemination and test tube fertilisation to increase the mobility of sperm.

A phase I clinical trial, 30 women were treated with Gel PKB171 for up to three times. Gel PKB171 was generally well tolerated and the most common side effects were local reactions like vaginal discharge and itching.

A phase II clinical trial, investigate the efficacy and safety of two concentrations of PKB171 versus placebo in couples with asthenozoospermia who wish to conceive. A total of 72 couples were planned to be included in the study. Finally, 28 couples were enrolled, and 11 couples were randomised. Within this trial, two concentrations of pentoxifylline gel were compared (5 mL of gel PKB171 containing 150 mg (3%) of pentoxifiylline, and 5 mL of gel PKB171 containing and 200 mg (4%) of pentoxifylline. Both doses were tolerated well and revealed no safety concerns as assessed by AEs, local Gel PKB171 tolerability, laboratory parameters, vital signs, gynaecologic and physical examination, or transvaginal ultrasound findings. This study was prematurely discontinued due to low numbers of eligible subjects and high recruitment failure rates, despite several protocol amendments. PKB171 gel was well tolerated and revealed no safety concerns as assessed by AEDTs, local IMP tolerability, analytical parameters, vital signs, physical and gynecological examination, or transvaginal ultrasound findings.

The aim of this clinical trial is to assess the safety and efficacy of the gel PKB171 compared to a placebo gel in couples with mild male factor infertility, unable to conceive in the last 6 and 24 months.

Additionally, the safety and local tolerability of Gel PKB171 will be further investigated.