I think the plant is Marsdenia tenacissima (Roxb.) Moon (Synonyms include: Asclepias echinata Hook.f.) of Asclepiadaceae.
There are publications showing it as a member of Apocynaceae.
It is known for its anticancer and many other medicinal properties.
Here is a paper on its medicinal properties:
ZHENGRONG HUANG,HAO LIN, YONG WANG, ZHIYUN CAO, WEI LIN, and QIANG CHEN, Studies on the anti-angiogenic effect of Marsdenia tenacissima extract in vitro and in vivo.